Simple, concise, and quite accurate. The difference b/w the two comes down to throat length and the NATO chambered weapon is far more accommodating to the .223 then the obverse.
Simple, concise, and quite accurate. The difference b/w the two comes down to throat length and the NATO chambered weapon is far more accommodating to the .223 then the obverse.
The graphics should help many understand the issues. A longer/looser throat/leade results in a softer start-
However, the issue remains, NATO is loaded to about 5000PSI more than SAAMI 223. So, a 55 grain 556 NATO round in a 223 Rem chamber produces as high as 77k psi, (SAAMI method) while the SAAMI chamber/round generates 50k CUP/55K psi.
Adding more confusion to the issue is the 4 yes, four different methods used to determine pressure- CIP ( European standard- 63500 PSI) NATO ( kind of hybrid 63000 psi) SAAMI (50k CUP/55k PSI)and US Army SCATP (55k PSI).
Interestingly, the hybrid chamber (223 Wylde in particular) make the best of both chambers- generous chamber body dimensions, tight throat, longer freebore and shallow leade angle generally produce better results with either loading and allow interchangeability with no risk of excessive pressure spikes.
The wide throat (.226” of the 556 NATO chamber allows for more reliable chambering when dirty, but also contributes to less innate accuracy than the 224 diameter freebore diameter of the 223 Rem and most hybrids, with almost no clearance, bullets are much more closely aligned with the leade into the rifle which contributes to better accuracy.
What chambers do the Warrior household AR15s wear? The NM Service rifles- 223 Wydle or 223 AMU ( for the 1/6.5-90 grain bullet 1000yard gun), the Varmint bolt gun- 223 Rem with 1.5 deg leade, the Carbines behind the doors? 556 and NATO Spec ammunition.