Category Archives: Weapons Education

Make the Tools to Make Bullet Jackets

John at NYC CNC shows you how to do it in this video playlist at You Tube.

Here’s the first of the series, so you can see what it’s all about:

If you let it play, it should play the whole list, but our You-Tube-fu is not strong.

John says:

 

Having been a long time shooter and reloader, I am undertaking my next project for my new Emco V13 lathe: Making Copper Bullet Jackets. The process steps are to blank a copper coin out of a strip of copper, cup it, then draw it in to progressively longer and thinner-walled shapes. The goal in this project is to end up with a 9MM jacket which will be about 0.6″ long and 0.352″ in diameter. That jacket can then be used in a swaging system (e.g. Corbin) and combined with a lead slug to make an actual bullet!

As he suggests, this doesn’t get you all the way there, but takes you far enough that fairly common reloading tools (the Corbin bullet swaging set-up) take you the rest of the way.  Corbin makes a bullet-jacket-drawing press set for .45 and .224, but not for 9mm.

The process John displays here is the identical process that large bullet manufacturers like Remington, ATK and Sierra use — theirs is just automated. Moreover, the same process that he uses here to swage bullets from copper sheet are used with brass to make cartridge cases.  (You just leave a thicker base for fashioning a primer cup and a rim).

Perhaps this will answer some of you preppers who fear that the loss of availability of commercially made cartridges mean an end to shooting. (You don’t even need electricity, although it surely helps. But in the early days of cartridge arms, lathes were powered by treadles, or water wheels.

Perhaps this will also give pause to some of the bansters who think they can disarm the public — for that is their aim, not the disarmament of criminals, who, like the poor, have always been, and will always be, with us — by banning ammunition.

For example, the late and unlamented Ted Kennedy, the intellectual runt of a Hitler-admiring anti-semitic bootlegger’s litter, saw an ammo ban as a backdoor gun ban:

Back in 1974, Kennedy knew that banning ammunition would have the same practical effect as banning guns. On the floor of the Senate, Kennedy said that the “manufacture and sale of handguns should be terminated” and that “existing handguns should be acquired by states.” And toward that end, he urged passage of his amendment to “require the registration of every civilian-owned handgun in America,” to “establish and maintain a nationwide system to license every American who owns a handgun,” and “to reduce the number of handguns in civilian ownership, by outlawing . . . all handguns except those intended for sporting purposes.”

But, Kennedy added, “if [banning handguns] is not feasible we may be obliged to place strict bans on the production and distribution of ammunition. No bullets, no shooting.”

It’s a measure of how far we’ve come in a third of a century that even the most liberal politician with the most secure seat (i.e., Kennedy’s successors in MA) have to preface their ban language with, “I support the 2nd Amendment, but…” or, “No one wants to ban your guns, but….

Sure, that’s the “reversionary but” that renders that part of the sentence before it a nullity, somewhat like the several minutes of praise for allah and the prophet that must be recited as the ritual opening of any cutthroat negotiation in the lands of the Arabs. It’s intended as a sop for uninformed voters.

But, this: many of the attempted legislative bans whose dead-ends were described in that April, 2008 article are non-starters today, given Heller and McDonald. They’re not just dead because they’re politically noxious, they’re equally toxic Constitutionally. Progress over the last dozens of years adds up; we’ve really shifted the Overton window towards gun rights and freedom. Not that we can relax.

But, reverting to the point of this post, as long as the know-how to manufacture ammunition survives, or can be recreated by creative minds, the Kennedys of the world can’t achieve their objectives of total concentration of armed power in their own hands. Having seen, and fought against, totalitarian societies of several kinds, all founded on some utopian vision of an improved lot for mankind, we can only view that as a good thing.

Plus… making your own dies for bullet jackets is neat. The videos vary from five to fifteen minutes long, but we found them hugely interesting. Also, if you view them on YouTube rather than on here, each has a comment section with a pretty good s/n ratio.

Here’s a Good Gun Review

The editors of Shooting Illustrated did something wicked smart — they gave one of those new “guns for gals” to an actual gal to review, but even more cleverly, they gave it to one who was able to appreciate the engineering, not only the feminine colors (wait. How many of the women you know drive pink cars? Not knowing any Mary Kay reps, my answer is ze-ro. Interesting fact, that). But in this case, the designers of the gun, European American Armory (and their production partners, Italy’s Fratelli Tanfoglio) redesigned the firearm around the fact that there is sexual dimorphism in the human species.

Di-what? That means, men and women tend to be different sizes and strengths. While there’s a lot of overlap in the distributions, both the mean and the positions of the tails of the distributions of things like size and strength skew far higher for men than for women. Which is why you’re going to see a woman on an NFL offensive line around the time a man wins the ladies’ gymnastics gold at the Summer Olympics, and Satan stops burning coal because he needs the carbon credits.

There was a time when metalflake was a guy thing, on cars. Just sayin'.

There was a time when metalflake was a guy thing, on cars. Just sayin’. Some EAA Pavona colors.

Here’s what our distaff, engineering-wise reviewer has to say about the EAA Pavona:

[W]hat sets EAA’s offering apart from so many in the field, is how the company handled the other half of the equation: the engineering side of things. Mechanically, what EAA needed to accomplish was to design a pistol that would be easy for a new shooter—perhaps with small hands and below-average grip strength—to operate, and still have it appeal to more experienced shooters as well. Fortunately, the platform EAA started with was a solid one.

The gun is based on the CZ-75. Back when the Czechoslovak Socialist Republic was being stingy with export licenses to the Evil Capitalists, the licensed their design to the Tanfoglio Brothers, whose early pistols were close copies, and whose current pistols are, like current CZs, more in the line of evolved derivations.

The Pavona is a single-action/double-action semi-automatic, with a long trigger pull for the first shot, and a shorter, lighter pull for subsequent shots. My trigger scale only reads to 8 pounds, and the Pavona’s double-action trigger broke just past the end of the calibrated area. The single-action pull broke consistently right at 4 pounds. The double-action pull, while heavy, was not gritty on the test sample, and the single-action pull had minimal take-up and broke cleanly.

It is just stupid-easy to shoot well, especially for a compact pistol in a service caliber.

Firing controls are also intended to be unobtrusive and snag-resistant. Unfortunately, they are not ambidextrous, although a southpaw might find it easier to activate the slide-stop lever with their trigger finger than a righty would with their thumb. This is a roundabout way of noting the reach to the slide-stop lever is a long one. I

The safety was easy to use and fell naturally under the thumb as the pistol was grasped. Further, unlike a 1911, the Pavona’s slide can be worked with the thumb safety on. That’s a good thing, because it means administrative chores like unloading the handgun or taking it apart for cleaning can be accomplished with the hammer cocked—so the shooter doesn’t have to fight the resistance of the mainspring while running the slide—and still have the safety on as an added layer of precaution.

That’s a CZ-75 feature, as is the ability to carry cocked-and-locked. If you carry cocked-and-locked, why carry a DA pistol? In our case, it’s for a second strike at some Third Worldian primer. The rest of you, keep toting those 1911s. The tradeoff is, as our reviewer notes, that you don’t have a decocker. Some people prefer a decocker to a safety (like in the Beretta 92G). Some want both as independent controls (hence, the fans of SIG’s service pistols). Some of us just live dangerously and point it at the dog while dropping the hammer with our thumb on it (just kidding! No dogs were harmed, or even threatened, in reviewing this review).

Conscious of the needs of new shooters or those with less grip strength, the folks at EAA took a two-pronged approach to remedying this potential pitfall. [The Petter rails-inside-frame design leaves little freeboard for grasping the slide to operate it — Ed.]

First, the company reshaped the serrations on the slide. Despite appearing cosmetically pretty with their shallow, scalloped cuts, when I gripped the slide, I was impressed by the purchase they afforded. There was no problem getting a sufficient grip, even with a thumb-and-forefinger pinch instead of my preferred over-the-top, whole-hand grab.

Another aid built into the handgun is the use of lighter recoil and mainsprings. The reduced-power mainspring (which is accompanied by a heavier firing pin to ensure reliable ignition) also makes it easier for those with less grip strength to cock the hammer before racking the slide.

You know we are going to tell you, especially the chick yous, to go and  Read The Whole Thing™. It’s also a pretty good example to illustrate the kind of stuff to cover in a review. Things like:

  • What’s special about this design?
  • Who is it best suited for?
  • How does it compare to a few guns everybody knows (or thinks he knows?)
  • When you shot it, and it didn’t jam, exactly how many rounds are we talking about?

Finally, a review has places for both subjective impressions and cast-iron facts. An extra plus in this review for trying to verify some of the manufacturer’s specifications. Sure, the manufacturer says it weighs this, has a trigger pull of that, and holds so many rounds in its magazine. I greatly prefer reviews where they verify these factory numbers. The ugly fact is that the numbers that come in the press packet (for those firms turned-on enough to have a press packet) come from the marketing department and they may have nothing but a nodding acquaintance with the numbers the engineering department is using when they QC the guns.

So we always like it when a reviewer gets the trigger gage out and that sort of thing. This was a good review. We liked it. We’re not the target demo for the gun, but we know people who are. And she’s dead right that the gun-store guys recommending snubby revolvers to women as EDC guns need to reexamine their preconceptions.

Oh, did we say who the reviewer was? Tam of A View From the Porch, one of the folks who made gun blogging look so easy that we followed ‘em in. As we close in on three years, it’s a damn sight harder than we expected….

A cool 1911 graphic

We saw this blurbed at Instapundit:

1911_graphic

The full thing by artist Jacob O’Neal is something you have to see. Because as cool this is, even clicked-to-embiggen, this is just one small part of it, as a static graphic. The real thing offers several views, and is animated. 

Boy. Sure wish we’d had this back in Weapons School, when two of us ran a study hall late into the night to try to save the guys who had been recycled from the class before us. (We did, but it was hard work — mostly by them, we just happened to be college boys with good study habits who could help out).

Go to his animations site, animagraffs.com and enjoy Jacob’s artistry. Along with the gun he’s got jet and piston engines and a tarantula. Then come back, hear?

Back now? Was that 1911 animation cool, or what? So, now go see the animated infographic he did for SilencerCo some time back. (And all you 1911 bashers who wanted a Glock, guess what’s hosting the SilencerCo Osprey in the graphic?)

Guy’s a talented artist. Some website looking for differentiation ought to commission him. (We don’t think we can afford him without crimping the toy budgets).

Wednesday Weapons Website(s) of the Week: Two FOIA Pages

question markThis is one of those Wednesday Weapons Websites of the Week, where we send you out to make your own experience. The reason is that there is an almost unlimited amount of quality information available here, but it’s all information that’s going to need to be winkled out using some awkward search facilities.

FOIA stands for the Freedom of Information Act, a 1970s law aimed at government transparency that has made many lawyers indecently rich for finding exceptions to shield misconduct and wrongdoing by government agencies or (more often) by senior government officials. Nonetheless, these sites offer the secrets of two agencies that have had a great deal of success as well as some spectacular failures; released documents tell the tales of both.

CIA FOIA Page

The CIA is subjected to a barrage of FOIA requests daily and has developed robust protocols to respond to  these requests, whether serious or frivolous. (The most frequent request, we’re told? Information on UFOs. The kooks are out there). The CIA has one of the more comprehensive and, fortunately, easily navigated FOIA sites in the Federal government.

A perfect example of the sort of declassified historical information the CIA excels at providing is this collection on the building of the Berlin Wall and what US intelligence knew about it at the time.

cia_west_german_paper_1960Here’s a specific example of the sort of thing you can find on the CIA site: a translated West German set of political objections to the Western Powers potentially renegotiating the status of West Berlin with the Soviet Union, from 1961 or thereabouts. Some of these objections are quite prescient and were narrowly forestalled by statesmanship at the time; others did come to pass, without seriously impeding the Western defeat of the USSR in the Cold War. (Or the USSR’s defeat of itself, perhaps). But the Germans had no way to know it at the time.

In addition, the Center for the Study of Intelligence and the Sherman Kent School for Intelligence Analysis‘s Occasional Papers are not part of the FOIA page, but they’re also on the Agency’s public website and provide a rich trove of declassified as well as never-classified material. Here’s a recent posting from the CSI, an unclassified extract of the classified in-house magazine Studies in Intelligencewhich deals with a secret Australian unit in the invasion of the Philippines and conquest of the Sulu Archipelago in 1944-45.

USAF FOIA Page

We went to the FOIA page looking for something very specific that we were promised was there — an accident report on an aircraft mishap this year in Kyrgyzstan to a tanker flying from Manas. We couldn’t find that, but we found so many other good things that we shrugged it off.

winter_study_group_1

winter_study_group_3To set up a remarkable example of the material available here, we’re looking at a recently (28 Aug 2014) released report of the Winter Study Group’s sensing sub-panel from 1960. The Winter Study Group was set up by Lt. Gen. Bernard Schriever USAF and managed by the Mitre Corporation in approximately 1956 to examine the chaos that electronic systems procurement had become. The sensing panel made interesting assumptions about the Soviet bomber and ICBM threat and about systems for detecting an attack. It is no exaggeration to say that this work led to the DEW Line, NORAD, and satellite early warning, just as the WSG’s overall work led to the AIr Force Systems Command’s Electronic Systems Division (which was established within a year of the final report) and the entire concept of Electronic Command and Control.

The report is a priceless time capsule of 1960 thinking, and the fear of The Bear is palpable in it.

winter_study_group_2

Unfortunately, the bad news: the USAF FOIA website has a human interface that might as well have been designed by Mitre in 1960, and it’s a bear (as in difficulty, not Russian, although it is a bit like a long Russian novel in a bad translation) to link an individual report (and impossible to link an individual .pdf). Your only hope is to search the site for WINTER STUDY GROUP, and Lord alone knows what you’ll find.

More recent information includes a report of investigation of a green-on blue incident in a command center in Kabul, that we hope to analyze soon; there are valuable lessons for everyone in a “safe place” overseas, and some important facts about the limitations everywhere of “good guys with guns” vis-a-vis bad guys with guns.

Both agencies are host to a lot of documents that are low quality (microfiches, photostats, old mimeographs) and tend to do a pretty lousy job preparing them for the web (they’re seldom OCR’d or printed to .pdf yielding a searchable document). But they have information you’ll never find anywhere else.  That’s the trade-off.

Notes

1. For more on the Winter Study Group, see pp. 13-14 of the MITRE history, Fifty Years of Service in the Public Interest. (.pdf) and pp. 192-198 of Johnson, Stephen B. The United States Air Force and the culture of innovation 1945-1965 (.pdf). Bolling AFB, DC: 2002. Johnson refers specifically to this study but it is another thing entirely to review the original document (as he no doubt did, writing an official history).

Ghost Gunner Update

You guys may remember the Ghost Gunner, the open-source CNC mill that we ordered a couple of months ago. According to the makers, the initial units should be shipping RSN1. Cody Wilson hasn’t been on the blog since November, but we didn’t share that update with you guys yet.

The first news is that the machine itself has been tweaked since it was announced.

Ghost Gunner Mk III

Improvements in our Mark III design:

* Single piece powder coated 1018 steel exoskeleton to improve rigidity per unit weight
*Reinforced A36 steel end plates to further improve rigidity
*A new open source GrBLDC brushless motor controller shield for Arduino.
*Oversized 125W NEMA 23 BLDC motor, electronically throttled to 72W.
*Spindle incorporation of industry standard ER11 collet system, supporting tools up to 5/16”

Those are all good improvements, although the steel exoskeleton looks like a manufacturing twofer that saves weight and reduces cost, with no net change to rigidity over the original design. Hey, if it can make the specs he claims, we’re all for it. But the ER11 collet is a big improvement over any proprietary system, as quality ER toolholders are readily available.

The ER system was developed by the Swiss company Fritz Weber Maschinenbau AG (now Rego-Fix) in 1972 and has become a standard. It allows a range of tools to be held in a single holder, which is nice; there are several ER sizes (larger number is larger) and ER11 handles a tool shank to 1/4″ / 6.5mm or so (Wilson says 5/16″). For a ½” shank, you’d need ER-20s. It is not a quick change tool holder, but the holders can be changed in the collet fairly quickly. This thread on Practical Machinist has some details (they’ve had some good luck with import tool holders, and discuss how to check them for run-out).

Back to GhostGunner, here’s what’s up:

For the rest of November we are setting up our work shifts and finishing our packaging. We begin assembly the first week of December and are still on pace for our Holiday fulfillment. Not too shabby, eh?

As for new orders, we’re thinking we will open them again in January. But you can always reserve a spot for the next round of machines on our waitlist.

This has been really fun. Ghost Gunner is still an open source project, and we will be releasing the designs and software as soon as possible. Stay tuned, ghost gunners.

via Ghost Gunner.

We’re a little concerned that we haven’t been contacted, because their lame order page ate the Address 1 line for Hog Manor (& Rong Brothers Aeroplane Works), and replaced it with the digit “4”, and we’ve been unable to reach anybody to make a correction. A bit discouraging, but it’ll work out.

They had no problem charging our credit card the same day, that’s for damn sure. Since it’s Wilson, we’re just glad we didn’t have to pay him in Bitcoin.

Still and all, we are in (IIRC) the third hundred or so — the $1299 batch.

Ghost Gunner Mk III w gun

What excites us about Ghost Gunner is not routing out AR lowers, the one canned application that comes with it, but the potential of using it to automate other small manufacturing gigs. We’re already thinking about setups for engraving and for modifying an A2 forging receiver to A1 profile. We’re going to need Wilson to fulfill his promises of open-source file formats, etc. A .dd format is a useless thing if it’s not documented and there’s no software that writes it. We’d feel a little more comfortable if the machine would take GCode.

But then again, it seems to be all open-source built, Arduino, GRBL, etc., so it probably can.

It may wind up being an expensive toy that gets used as a sweater rack, like a fat guy’s treadmill (wait… we just described our exercise room right now. And us). It wouldn’t be the first.

If there are developments from GhostGunner, they’ll probably be tweeted by the Defense Distributed or Cody Wilson accounts:

https://twitter.com/DefDist

https://twitter.com/Radomysisky

The FOSSCAD channel is unrelated, but also worth watching. Apparently the real goings-on go in in IRC, and only announcements pass in Twitter.

https://twitter.com/fosscad

Notes

1. RSN – Silicon Valley/Startup Culture acronym for “Real Soon Now.” Sometimes serious, sometimes ironic. Here, we’re not sure. They seemed to be on track in November, so we think maybe serious.

Tank Turret Rotation in WWII

a rollin foxholeLet’s adumbrate about tanks again. Fascinating things, although we always took Willie and Joe’s words to heart: a movin’ foxhole attracks th’ eye. (Alas, the only version of that classic we could find does not embiggen). Anyway, our interest has been more, shall we say, historical curiosity than professional.

To put it another way, we’re all about studying them, but we’re just as glad we spent our career under the sky and stars rather than under some inches of cold-rolled.

The nature of tank war is the nature of all war, in general, with some specialized details particularly adapted to the idea of fighting a mobile machine, and units of these mobile machines.

In armored warfare as in any other, the ability to fire the first shot is the guarantor of life. The ways you can get the first shot include:

  1. Seeing the enemy first. This has some impact on tank equipment as well as tactics. Some tanks are ill-equipped for observation in a 360º plane, making them very vulnerable for an off-axis attack. Of course, the crews train to fight the tank they have, and will develop methods to minimize this weakness.

    M26_Fireball

    T26 Pershing named “Fireball”. The 88mm mantlet penetration killed the tank and two of the five crew. Germany, 1945. They probably did not see the Tiger 100m ahead that hit them, but they were backlit by a fire. The Tiger also hit their muzzle brake with another shot.

  2. Concealment and firing from ambush. As many an infantry school instructor has crowed to students at once excited and aghast: “Ambush is murder and murder is fun!” This rewards a tank that can fire from concealment, without making a lot of noise that alerts the enemy’s dismounted scouts, without a lot of movement to betray the position. In addition, there are great advantages in the defense to be able to fire from a hull-down position. (And to a small turret, which complicates the enemy’s target solution).
  3. Outranging the enemy through superior accuracy or terminal ballistics. The components of accuracy are optic, gunner, gun, and integration. While it’s obviously important to hit the enemy first, it’s also important not to hit the enemy at a range beyond that where you can kill him. Otherwise, you’ve exposed yourself and blown your first-shot advantage for nothing.
  4. Getting on target faster. Here optics — including a good field of view for the gunner — and superior speed and control of main gun aim are the objective. If your turret slews very fast, that’s good, but not if the fast slew can’t produce fine control.
  5. Having more tanks, so that the enemy was servicing another target when your first shot kills him. This is a production and reliability play, but also rewards commanders for ingenuity in bringing their forces to bear in greater numbers at a decisive point.

The next best way to win the fight was having the first effective shot because your tank was harder to hit (or, harder to kill). This is clearly a less desirable position to be in than the one where you drop your tungsten calling card into the enemy’s brisket when he still was unaware you were there.

By World War II (and still today, apart from some unusual vehicles in both cases) the design of a tank was stabilized as a rear-engine vehicle with a rotating armored turret carrying primary and (most) secondary armament. The gun was placed on target in elevation by the gunner raising or lowering the barrel, and in azimuth by the gunner (with direction and sometimes assistance from the commander) slewing the turret.

Caught in the open: fate of many a tank and crew.

Caught in the open: fate of many a tank and crew.

In a textbook illustration of the principle of convergent evolution, WWII tanks of all nations were more alike than they were different. But different nations’ main battle tanks rotated their turrets differently — and some were effective despite a much slower rotation than their peers, which seems illogical.

  • British and Russian tanks rotated electrically. If you ever owned a ’60s British car, you have to have some sympathy for the grimy crews and mechanics struggling to keep the ancestor of Lucas electrics humming. British tanks used spade grips for the controls to rotate the turret. The British had a mode switch which let the gunner control traverse on a “coarse” or “fine” setting. The T-34 used electric for coarse and manual for fine traverse. The T-34/76 used separate wheels for electric and manual, attached to the same traversing gear. In the T-34/85, though, the same handle was used as a lever for electrical control and a crank for manual — ingenious! Rather than explain a T-34’s system, which used the same controls for manual and electric traverse, we’ll let the Military Veterans Museum show you in this 1-minute video:

  • Germans used a hydraulic system, driven by power take-off from the main engine. This was a mechanically simple and reliable system, but it had a key deficiency, as we’ll see. The Germans used foot pedals to slew the turret — left pedal went left, right pedal, obviously, right. The gun was then laid with final precision using a manual handwheel.
  • American tanks used a hydraulic system, but drove it electrically. Instead of a PTO from the main powerplant, like a tractor, the hydraulic system was energized by a pump driven by an electrical motor. Also, only the Americans applied stabilization gyroscopes to tank main armament, beginning with the M4 Sherman (on the early Sherman, in elevation only). This gave the tank a rudimentary shoot-on-the-move capability, and perhaps more usefully in tank fighting, reduced the amount of displacement needed to get on target after moving. When hydraulic system production threatened to constrain tank production, some American tanks were fitted with an electrical system also. The electrical substitute system was designed to have similar performance. American tanks used hand controls to slew the turret, and a foot pedal to fire the armament.
  • Most Japanese tanks had manual traverse only. Indeed, some light tanks and tankettes simply had a machine gun turret where the gunner moved the turret by leaning on the machine gun! While Japanese artillery and naval guns often featured bicycle pedals for traverse, the larger tanks had crank wheels to traverse the turret for coarse position. For fine position, the gun itself usually had a few degrees of traverse, and separate hand wheels. While Japanese naval optics led the world, their tank and AT optics lagged, as did most other aspects of tank development. Late in the war, electric traverse was incorporated in the Chi-Ha and Chi-Nu tanks; early Chi-Has, the bulk of those encountered by the Allies, were manually operated.
  • Some early and light tanks of many nations had manual rotation, and almost all power-rotating turrets had manual as a back-up. For example, the Panther had not only the gunner’s fine-tuning handwheel, required because of the lack of precision in the hydraulic system, but also a hand-lever for the gunner and a separate wheel for the loader. Having backups like this was important, because reliability of the systems on WWII tanks was not all that great. Engines, which were often modified or derived from aviation engines, lasted a few hundred hours before an overhaul was required, and hydraulic or electric motors were scarcely more durable. The tanks used at the peak of the war in Europe were war babies, designed once combat was underway and designed and manufactured with all due haste. They hadn’t had a long debugging cycle. Wartime memoirs are full of tales of operating with one or more systems degraded.

While in theory any system can be engineered to give you any rate of rotation, the German approach of shaft-driven hydraulics had a weakness: the turret could only power-traverse if the main engine was running. For the fuel-critical Germans, this was always a problem. This approach also meant that the speed of rotation depended on engine speed. You only got full-speed rotation at full throttle; at anything less, it was degraded.

How fast could turrets rotate?

The vaunted Panther tank had, in its first iteration (Panther Ausführung D), one of the slowest-turning turrets in the war, taking a full minute to traverse 360º. The gearing on the turret was changed in the Ausf. A, the next version, and all subsequent Panthers, giving the tank a competitive 15-second full-circle. But that didn’t last; a November, 1943 decision to govern the engine to a lower max RPM reduced slew rate to 18 seconds on Panthers from that point forward — if the crews didn’t learn about and adjust the governors. This was done to try to increase engine reliability: more Panthers were being lost to breakdowns than to Allied gunfire.

What’s interesting is that even though the early Panther turret was quite slow, it was still fast enough to track all but the fastest-moving tanks. All greater speed than a circle-a-minute buys, then, is ability to change targets, or get on a sighted target, faster.

The American system spun a Sherman turret 360º in fifteen seconds, too. The system in the M36 tank destroyer had the same performance, also. (Not surprising as the automotive  gear in the tank destroyers was lifted from the Shermans).

The undisputed slewing champ of WWII tanks was the Russian T-34, which could bring its turret all the way around in 12 seconds.

We couldn’t find any credible information on the slew or traverse rate of Japanese tanks.

The final lesson in all of this brings us back to convergent evolution: despite the different approaches taken by the major tank producers of the era, their performance was roughly similar (excluding the lagging Japanese, who deemphasized tank development and production because of their limited production capacity, and overwhelming naval requirements).

Sources

Directorate of the Armored Forces of the Red Army. T-34 Tank Service Manual. Translator unknown. Retrieved from: http://www.allworldwars.com/T-34%20Tank%20Service%20Manual.html

Green & Green, Panther: Germany’s Quest for Combat Dominance. pp. 107-120.

Military Intelligence Division. Japanese Tank and Anti-Tank Warfare. Washington: War Department,  1 Aug 1945. Retrieved from: http://usacac.army.mil/cac2/cgsc/carl/wwiispec/number34.pdf (bear in mind that as a wartime intelligence document, this is not fully-processed history!)

Zaloga, Steven J. Japanese Tanks 1939-45. Oxford, England: Osprey, 2011.

Zaloga, Steven J. M4 Sherman vs. Type 97 Chi-Ha. Oxford, England: Osprey, 2012.

Afghan M4 Makeover, Step 1: Vintage Stock

We remember seeing the 6921 as it shook out of the box yesterday. It came with a maybe-good-we-dunno Rogers Super-Stoc, which is not what we had in the hills of the Hazarajat.

unbox_20_new_stock

So we needed to go to the parts box for an original Colt Fiberite stock, of which we had a number even before putting in the order for the carbine.

But it turned out, we had a guardian angel looking out for us. One day, while the 6921 sat waiting for the stamp, we got a ring from an old friend who was then still in the old unit.

“What was your rack number?” Easy enough to remember. Jeez, we inventoried the team, and even the unit, weapons often enough. (The Army requires frequent serial number inventories which must be done by two officers or senior NCOs). Normally used and broken weapons parts are turned in, but the unit had a shipment of new SOPMOD stocks, and someone somewhere made a decision that the decade-plus-old, war-weary and well-worn stocks, were dumpster food. It would cost more to collect and ship them to DRMO than they could possibly bring at auction. So they were thrown out.

Needless to say, any of the guys who wanted one, brought one home. And our buddy — God bless him — brought ours home.

unbox_28_revert_to_fiberlite_stock

Dang. A real piece of the exact gun we had in Afghanistan, is the first part of our reproduction of that stalwart companion. Who else can say that?

Now, practically, the stock is inferior to the Rogers stock on several planes. It’s a little looser and shakier on the stock extension. The Rogers has the trick locking lever, which is nifty. Neither one really has a good cheek weld, but the Rogers curved buttplate is a lot more ergonomic.

And, of course, there are other superior stocks out there. But, like the Marine mantra about This is my rifle, “there are many like it, but this one is mine.” Not to go all seagull or anything.

(Note: we were wrong yesterday if we said the initial weight of the 6921 with the Rogers was 6.6 and then we established it was 6.5 after weighing the rifle with the Fiberite stock. As this photo, which we didn’t look at when writing the post, reveals, the second set of weights was 6.6, meaning the 6.5 was the initial weight result).

There’s a long way to go in our M4 Makeover. Next installment? Rails and foregrip.

Colt M4LE Model 6921 Unboxing

Objective: build the best possible transferable replica of an Afghanistan, early war, Special Forces carbine. Specifically the one we toted around Kandahar, Bagram, and on Operation Roll Tide with the 3rd Battalion of the Afghan National Army in the Khamard and Madr Valleys of central Afghanistan.

We started with noting what a young(er) WeaponsMan toted around the hills: an early M4A1 to which the SOPMOD I kit came as an afterthought (and because our company was remote from, and in a different state from, Battalion and Group HQ, we didn’t get the whole kit until we returned, because the Group S4 ratholed it and forgot about it. Supply, a most under-appreciated field of endeavor). We figured the nearest we could come to it was a Colt LE M4, as it would have roll marks similar to the combat-carried weapon, and the correct barrel length. We ordered the gun two years ago, and it came quickly to our FFL.

unbox_01_box_end

The trip to the workbench was long and eventful. An attempt to set up new trust came unglued, and after a second attempt, we moved forward with an individual purchase. (And yes, that means when we get the trust straightened out we’ll have to pay another two bill transfer tax to put it in the trust). Then, of course, ATF fell far behind in approving NFA transfers. They finally got the paperwork after all of our delays in March, 2014; in October, at the 6-month point, we called NFA Branch for an update.

“It’s all good,” the examiner said. “There’s nothing wrong with your packet, and it’ll probably be approved.”

“Great!”

“…in January.”

“Oh. Well, thanks. Out here.”

But the examiner underpromised and overdelivered. In November, we got a call with the welcome note: “Your stamp’s here!”

Cool. Two months early! We couldn’t pick it up till this month, so it was like getting an early Christmas gift.

You’ve seen the box; overleaf, there’s a photo-rich set of detail pictures of the carbine after the jump below. The photos are unretouched except for cropping, setting levels, erasing serial numbers (a bit silly, as the guys who scan the net for serial numbers already have this one) and stripping EXIF data.

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Gun Oddity: Beretta ‘Combo’

We prowl the halls of GunBroker, half looking for stuff to buy, and half looking for edutainment. This is an example of the latter, in that we never knew it existed: a Beretta 92/96 Combo, which appears to be a factory set with slide/barrel/recoil-spring units in 9mm and in .40 S&W.

beretta 92-96 combo case

Here’s the seller’s blurb:

For sale a Beretta 92/96 Combo, 9mm and 40s&w. As far as I can tell it is unfired, Has the original blow-molded case, original box and all paper work. Barrels and lower are stamped COMBO. Also has extra grips. I will pay for transfer using my local FFL if picked up locally. When I say rare, look around, you won’t find many… IF any! I can send more pictures if you are a serious buyer.

beretta 92-96 combo

Looks legit to us. The number of these that were produced isn’t visible in any official document, but web pages here and there offer up claims of 500 or 2,500. They come up for sale from time to time, at a premium over a 92 or 96 in equivalent condition.

There is a great deal of modularity in the M92 (etc) design, and the 92 and 96 have identical frames. Therefore, they are convertible simply by swapping complete upper (slide-barrel assembly-recoil-spring), and, of course, the magazine. The recoil spring assembly can be reused, but it’s easier to just have a whole unit to swap. (Also, the recoil spring is probably the single most life-limited part in the Beretta, especially the 96, which has the same spring as the 92 but punishes it more).

There are some limitations on swapping, mostly involving odd-lockwork guns and early (pre-92FS) guns. You can even get some use out of just a 92 barrel in a 96 slide, although the reverse won’t work. However, the newer “Brigadier” slide (the one with the thickened area by the locking block) may have fewer interchange options.

What’s amazing is that guys will still write that you can’t swap uppers from 9mm to .40 on Berettas. This Combo is living proof that Beretta thought you could!

Wednesday Weapons Website of the Week: full30.com

You may have been to Full30.com already, as it’s the home of InRangeTV, which we’ve been remiss about promoting, and have been meaning to plug. We’ll let Ian and Karl explain what InRange is:

InRange is a collaborative project between Ian McCollum (Forgotten Weapons) and Karl Kasarda. After watching the gun program landscape of cable television decline into a wasteland of explosions and ginned-up drama, they decided to produce a show that would appeal [to] the intelligent and sophisticated gun owners and gun enthusiasts worldwide.

In an internet video world that’s dominated by the childish play of FPSRussia and the soporific ramblings of 30-minute gun reviews, is there room for a show for the thinking gun enthusiast?

Here’s a far-out example: Karl in a 2-gun match with an updated FG 42. Before you laugh at the idea that a 70-year-old design can keep up with a “modern” AR (which is, after all, a 60-year-old design), watch to the end and see how Karl did out of 47 shooters. And here’s a follow-up with Karl and Ian discussing the features of the modernized FG. It’s like hanging out with two fellow gun nuts — in HD. “We’re putting out this video because we think this is an awesome gun,” Ian says.

In addition to those, there are a handful of other videos from InRange already posted. They’re all good, whether it’s Karl describing the forgotten battle at Dragoon Springs where a small Confederate foraging patrol found itself overwhelmed by… Apaches, one of their patented historical-gun matchups at a live 2-gun match, or an interview with AR pioneer Jim Sullivan.

“But wait!” our inner Ron Popeil cries out. “There’s more!”

Because Full30.com isn’t just the host of InRange TV, even though InRange is our favorite channel there (imagine a cable network with different channels; that’s what Full30 is for people interested in gun-related videos).

Some of the bigger guns (pun definitely intended) of YouTube notoriety are here, including MAC (the Military Arms Channel) and Iraq Veteran 8888. Here, for an example, is a very thorough video by MAC about the FN F2000 and especially FS2000 rifles that hits all the high points (ergonomics, for example, forward ejection makes it ambi-friendly) and low points (STANAG mags only, thank you very much) of the system. The video actually made us want one.