Vietnam M16 ammuition


I guess it is pretty well know that when first introduced in Viet Nam the M16 had a lot of jamming problems. One of the things that is often sited is that the 5.56mm ammunition had to be improved, I think it burned too slow and lead to fouling in the humid temperature. ?Question, does anyone have some of this original 5.56mm? George


Strictly speaking, the original ammo used to develop the AR-15 worked fine. It was the initial production ammo, which used a different propellant which produced far more fouling problems and led to the guns jamming when not cleaned (the soldiers were told that cleaning was unnecessary and weren’t given any cleaning kits) which caused the problems. Compounded by the fact that the chrome-plating of the chambers and barrels originally specified was omitted to save money.

To be fair, the cock-up wasn’t entirely the army’s fault: I believe that Stoner was told which propellant the Army would use, but developed the gun using a different type.



Tony pretty much summed it up, from what I understand. Early (developmental) 5.56x45 was loaded with single base (nitrocellulose) extruded powder and later volume production used double based (nitrocellulose/ nitroglycerin) ball powder if I remember how the story goes. The ball powder led to fouling problems in the early M16 rifles.

I don’t know if early production contracts were let for both types or just the ball powder loadings, but it’s possible that early date 5.56 ammunition (to the mid-60s) could be ID’d for its powder type by the manufacturer? I would associate the single base powder with DuPont (Remington ammunition) and the double base powder with Winchester/Western products, but that may mean nothing. Perhaps someone who collects the early 5.56 could chime in on the topic…I’m already in way over my head!



I’ve never met a cartridge that didn’t need its’ bullet pulled to see what is inside. I have several drawers of such dismembered specimens. I’ve learned that you can always expect the unexpected. Ball powder in Big Green and stick powder in Big W occurs more often than you might think. Now with ATK as a major player we will be finding even more gotchas.

George, suplus ammo shows up on Gun Broker all the time. Simply pick the year that you think is what you want and buy a box or two. Talking to a few VN vets may give you more insight into what went on then. Better than all of the reading you can do.



While Eugene Stoner was certainly a key player in the development of the 5.56x45 cartridge and the M16 rifle his real interest lay in the AR 10 and the 7.62MM NATO. The first Armalite SCHV prototype was actually designed by Robert Enewold and chambered for the 222 Remington. It was later redesigned as a scaled down AR 10 by Robert Fremont and James Sullivan.

All unfamiliar names, now largely lost to history.

End of today’s history lesson.



Thank you for the replys. The Wikipedia article on the development of the M16 summed it up this way; powder was the problem, DuPont could not make enough of the nitrocellulose-based powder, so a company called Olin Mathieson provided back up production, however, their powder was nitrocellulose-nitroglycerin. Olin WC 846 gave the round the desired 3,300 foot per second but it increased the rate of fire too high which resulted in the fowling. ?So maybe there are headstamping unique to Olin Mathieson manufactured ammunition dated 1964-1965??



That’s where I was going with the Remington vs. Winchester/Western (Olin Mathieson) line of thinking but had a feeling it wouldn’t be that easy. Ray doesn’t hesitate to tear down a cartridge to see what’s inside (dare I say he enjoys doing just that?) and I think what he’s saying is that the case markings are not going to guarantee the type of powder used. If you find a group of 5.56 from that era, likely taking a sample look is the only way to verify the powder type unless they are in boxes marked with lot numbers that can be traced to specific loadings. Again, others likely have better insight on the caliber than myself…



The Black Rifle M16 Retrospective
by R Blake Stevens and Edward C Ezell
Enhanced Second Edition, 1992
416 pages, 441 illustrations

A great book on this subject .
It’s well worth the price.