12 Apr 23
“We are kept keen on the grindstone of pain and necessity.”
HG Wells
The M4 is doing anything but dying!
Same can be said for the RA/XCR, CETME, even the Ruger Mini-14
BCM (Bravo) is making a new M4 upper receiver. Forged 7075 material, but thicker walls for more rigidity. The benefit is that it keeps the bolt and barrel-extension aligned, reducing stress in the bolt.
Both Geissele and Surefire now make bolt-carriers with improved cam geometries. Geissele also claims improved bolt metallurgy.
POF and Ruger are both making compact (small frame, 5.56 size) 308 rifles that are notable for a substantially increased strength steel used in bolts. I have a copy of POF’s “Revolution,” (308) and it is wonderful!
I don’t hear many complaints about Stoner’s original (incorrectly described) “direct-impingement gas system” What Stoner actually did was move the gas-piston back into the bolt-carrier.  It has stood the test of time!
Moving the gas-piston forward into the forend (H&K 416) has resulted in a reliable system too, albeit more expensive to manufacture.
Suppressors are improving also, with many now featuring “flow-around” designs with a good deal less back-pressure, and less carbon residue, than before.
As for the caliber itself, 5.56 (223) is what it is. It’s very effective against human threats within 150m, but doesn’t penetrate much at any range. Still, 55gr hardball works just fine against the vast majority of criminal threats. 55gr all-copper bullets work even better! I don’t like heavier bullets, but I’m in the minority. I’ve used the former for serious purposes, and my experience has been positive!
For military purposes, increased range and penetration are needed (in the opinion of most), but for personal domestic defense, and as a police patrol-rifle, the light and compact 5.56 autoloading rifle w/30round magazine is close to ideal!
All attempts to manufacture “enhanced performance” 5.56 ammunition, featuring increased pressure, have resulted in broken guns. Not recommended!
With history as our guide, chances of the new 6.8mm round (277 Fury) superseding the 5.56 any time soon are small indeed, particularly when our new rifles all start breaking due to a diet of hyper-pressure ammunition!
Too much pressure; too much weight. And, with conflicts ongoing (and imminent) in Israel, Taiwan, and Ukraine, there will be scant opportunity to “fine-tune” this new 6.8mm system!
Thus, the M4, et al, will likely be “the standard” well past our lifetimes!
Every Operator should have a copy, and keep it handy!
“Seek respect, not attention.”
Roy Bennett