This article has been around for years, but it’s still worth reading. Mike Pannone is a fellow 18B and someone with nearly immeasurable M4 experience. He was an instructor for, and one of the designers of, AWG’s combat shooting school, which prepared a lot of guys for successful combat in Iraq and Afghanistan. A friend who was the SJA at AWG raved about that course. Mike is pretty well known in the shooting and training community.
Mike has very extensive comments on the M4 at Defense Review, which stem initially from a discussion of fouling. We’ll just quote his conclusions from this piece below, and also recommend his article on reliability issues, and his follow-up on diagnosing the root cause. Conclusions from what we suppose you could call the “fouling piece“:
Fouling in the M4 is not the problem. The problem is weak springs (buffer and extractor), as well as light buffer weights (H vs. H2 or H3). With the abovementioned drop-in parts, the M4 is as reliable as any weapon I have ever fired, and I have fired probably every military-issue assault rifle fielded worldwide in the last 60 years as a Special Forces Weapons Sergeant (18B). An additional benefit of the heavier spring/weight combo is that it transmits the energy impulse of the firing cycle to the shoulder over a longer duration, lowering the amount of foot pounds per second and dramatically reducing the perceived recoil. Follow-on shots are easier to make effectively, and much faster, especially at 50 meters and beyond.
I reliably fired 2400 rounds (80 magazines) on a bone dry gun, and I would bet that is a lot more than any soldier or other armed professional will ever come close to firing without any lubrication whatsoever. So, disregard the fouling myth and install a better buffer spring, H2 buffer, enhanced extractor spring and a Crane O-ring (all end user drop-in parts). With normal (read “not excessive”) lubrication and maintenance, properly-built AR-15/M4 type rifles with carbine gas systems will astound you with their reliability and shootability.
There is a great deal more to the article than that; we just gave you a little bit. (For example, if you read the whole thing, he provides the sources for the upgraded parts he uses).
Mike’s articles are collected at the CTT Solutions website, although the articles link back to DR.