Investigators on the site of the mishap that killed two M18 Hellcat Gun Motor Carriage restorers.

Investigators on the site of the mishap that killed two M18 Hellcat Gun Motor Carriage restorers.

An anonymous commenter using the name “Cannonman” has made some serious allegations about the cause of the deaths of Steve Preston and Austin Lee during a live fire demonstration of an M18 Hellcat tank destroyer in Oregon, previously covered by WeaponsMan here on 27 October and here on 29 October.

The folks were loading their own ammo, the only “correct” component being the M26 cartridge cases. They did not use long enough primer flash tubes. M30 smokeless propellant, triple-based, smaller grain size, was used vice large-grained M1 single-base propellant. Navy projectiles, having longer and larger-diameter driving bands as opposed to Army, were being used. Cases were loaded with 1/2 lb. black powder dumped in base of case, cardboard wad, then 3.5 lbs of M30 propellant.

Why is “Cannonman” using the comments here at WeaponsMan.com to send this message?

I am putting this info here because authorities won’t release any info and the facts need to get out. The very dangerous load caused an extreme overpressure in the chamber shattering the breechblock and cracking the breech ring, sending hot gas and fragments into the occupied turret.

If that was really what they were doing, including using black powder as a sort of gaine in the ignition train, it’s amazing they ever got the thing to fire.

Right now, all we have on this is a single, anonymous source. We welcome further input in the comments or to hognose at network impossible dot com.

This entry was posted in Crew-Served, Safety on by Hognose.

About Hognose

Former Special Forces 11B2S, later 18B, weapons man. (Also served in intelligence and operations jobs in SF).

10 thoughts on “Tank Destroyer Fatalities — Caused by Bad Reloads?

Ordhistorian

Yes indeed, they were using military primers designed for 40mm Bofors cases. They did not use the 19 inch long igniter tube on the top of the primer, that would be filled with black powder to ignite the propellant. They fired 2 or 3 rounds before the gun blew up, and the first couple of rounds were hang-fires. That is when they started putting a black powder igniter charge in the bottom of the case. All of their rounds were short, so instead of raising the barrel, Steve said “I guess we need to add more powder”, upon which Chuck (the supposed explosive expert that was being paid $1500 a day to be there) said “Say no more”. He then increased the powder charge from 3 Lb. to 3-1/2 Lb. and threw a handful of black powder in to mix with the increased propellant charge, intermixing it with the M30 cannon propellant.

I don’t know if they were using a cardboard “distance piece” to hold the powder in place at the bottom of the case. If a distance piece was not used, the powder would lay on its side, allowing the ignition to flash over the top of the charge and possibly detonate it instead igniting it to burn.

The M30 propellant they were using is designed to be used in 155mm Howitzer propelling charges. The grains are much larger (0.46 inches X 0.935 inches) than the M6 propellant (0.3 inches X 0.7 inches) which was designed in the 50’s to be used in the 76mm gun. It is no wonder they were having hang-fires, because the powder grains were too big and slower burning. Intermixing the black powder with the propellant was insane! Anyone that has ever read a reloading manual knows that you never mix powders in the same charge. Adding powder instead of raising the muzzle is the stupidest thing in the world for any shooter to do.

Lastly, as an added note, Chuck Hegele, the supposed “Explosives Expert” has now been involved in blowing up 3 pieces of artillery, the Hellcat twice, once in the summer of 2013, and most recently this particular incident. In the Summer of 2014 he blew up his own 8 inch Howitzer, and the video of that is on YouTube. The first incident with the Hellcat in 2013 occurred because they were using 50 BMG primers, instead of military artillery primers that have an isolated floating firing pin that seals off any gas from the primer. They had a pierced primer in the 2013 incident, and gas blew back through the firing mechanism, destroying it. Luckily no one was hurt at that time.

looserounds.com

May I ask where you are getting this detailed info about their powder charges etc?

S

In the trivial amount of research I did into BPCR, I learned that duplex loads, and worse, short-loaded BP, is dancing with the devil. The things I’m hearing here are shocking….and to read that someone asked 1500 smackeroos a day and then did things like this….removes my compassion for anyone killed alongside them. I was getting set to be ultra cautious with 120 vs 110 grains of BP in a .45/120 case, and Einsteins like this are slinging it around by the pound??? Ok, the average worst I was expecting was a ringed chamber, but thats after I’d shelled out several gunbucks on a properly strong action by a reputable smith….but still, it could have involved an eye. At the least, a missed shot, and how precious can a bullet on target be when it counts….and when it’s driven by look-at-me over here BP??? What in the name of Browning were these schmucks thinking?

If you’re going to play with serious gear like this, ffs why not stick a quarter mile lanyard on the firing mechanism and take the chance on some merely entertainingly expensive footage to laugh off your screwup, rather than eating it all, eye to eye? Sorry, dumb is as dumb does, and the only regret I have at hearing these latest revelations is that some scumbag somewhere will use it as an excuse to ban others from using such equipment, regardless of their proficiency (or rather, as an excuse to disarm the proficient, lest they succeed in defending themselves). Dammit, wakeup. If an amateur like me gets it just a little bit, how about these “experts”? Wtg.Thanks, mate.

Next down the pike here, I may be facing not only ISISjr, but also the regime that imported them while it robs me. What can I use? Repurposed newyear’s fireworks, and battlefield pickups? My fucking body doesn’t do what I tell it to anymore, I have to play safe now. And some of you whine about cc carry or not, or which gun to add to the dozens in the collection, when there are others in this world who’d give their left nut for just a look at the stuff you sneer at in the pawnshops. Wake up, because worse than starving in our drought, you may die of surfeit in your plenty. And the hobbyists entering the Judgement to come, on account of some foolish hubris with toys?…..thanks for the lesson, but we learnt that bit already. Next time, find another entertaining way to die that doesn’t bear such influence on important things…..you dickheads.

Ordhistorian

The information I posted came from a variety of sources. The proper established military load for the gun is documented as 3.75 Lbs. of M6 powder, and is written in the September 1950 print of the Army Manual TM 9-1901 Artillery Ammunition. The data regarding the size of the individual powder grains came from measuring the sample powder grains that I have for reference, using a micrometer. Information about what happened that day regarding the firing and loading of the individual rounds came from a number of people that were there observing what was going on.

913A

While this is not video from the same time as the accident, it does show a reloading process that had been used by these gentlemen, and is very foretelling. https://youtu.be/oKxmrv9uV_s?t=331

Ordhistorian

After watching the video, a person could draw some conclusions, but some of them would be wrong. It is plain to see how they manufactured their first attempt at primers by making the brass insert that held 50 BMG primers. The video editing leads one to believe they were firing High Explosive projectiles, but in reality the projectiles fired were solid zinc, and the ones in the video were just for show. The video shows them firing three rounds, and they might have fired a couple more, but that is when the pierced primer blew up the firing mechanism. Shooting the footage for the video, and their first firing of the gun, was when they blew up the gun the first time. They were using reduced loads with the solid zinc projectiles to shoot the gun for the video shown on YouTube, whereas the loads they were firing when the men were killed were near maximum in order to get the velocity they needed to penetrate the armor plate target.

Here is the video of when they fired the 8 inch howitzer. Observe the “Professionalism and Safety”:

https://www.youtube.com/watch?v=IzdQq1YwE0A

Hognose Post author

Thanks. I couldn’t find that video when you mentioned it before. I’ll view it after posting this comment.

In the Combat Cash video, Chuck’s joking, “If we make any mistakes, we’re dead,” seems a lot less funny in retrospect.

I think the biggest reason that nothing’s been released on this yet is that ATF and the State Police are trying to come up with some way to prosecute somebody for something. If they had concluded it was an accident, harm but no foul, they’d have held a presser already with preliminary information, as they do for highway accidents, as the NTSB does for air and train mishaps.

Things like these videos are evidence. I’d be shocked if the investigators were not reading this site right now. No subpoenas yet; if they try we’ll fight them just as a matter of principle. (And to the extent I understand the law, we may well lose. Any LEO providing insider information best send to hognose at network impossible dot com for a phone number, using a burner address).

Sommerbiwak

“If a distance piece was not used, the powder would lay on its side, allowing the ignition to flash over the top of the charge and possibly detonate it instead igniting it to burn.”

You are sure the deflagration turned into a detonation? Rare thing with gun powders. Serious pressure spikes obviously happened in the accident, but a true detonation?

Hognose Post author

Could with the black powder.