Quote Originally Posted by bigedp51
grouse

Google is a wonderful tool and you can find any information you are looking for, the "PROBLEM" is where you get your information and "WHO" to believe.

The .223 Remington and military 5.56x45 NATO are the "SAME" chamber pressure "but" military NATO EPVAT testing is measured at a different point on the cartridge than the American SAAMI testing and that is why you see the differences in pressure readings. If you look at European CIP pressure testing the two cartridges are rated at the same pressures. (CIP is the European equivalent of the American SAAMI) Also if you look at the American SAAMI warning you do "NOT" see a chamber pressure warning, you see a warning on the different chambering methods dealing with the throat or leade for the military and civilian SAAMI.

[img width=461 height=450]http://i122.photobucket.com/albums/o254/bigedp51/556natochamberversus223remingtonchamber02.jpg[/img]

The military throat or leade is longer for the heavier bullets like the 62 gr SS109/M855 and even heavier XM288, M855A1 class ammunition and this could "possibly" cause higher pressures in civilian chambers. The standard M193 55 gr ammunition would not be a problem in any commercial .223 Remington.

grouse, 95% of the answers you get in gun forums are going to be wrong on this subject and your best bet is to do your own research on this subject from "factual written documentation" and not misinformation and guesswork in forums.

Below is some food for thought, I have a Stevens 200 in .223 Remington and I'm shooting Hornady 68 gr BTHP match and 75 gr BT A-MAX bullets in my Stevens with its 1 in 9 twist. (home made civilian M855 & M855A1 ammunition.



The people who "might" have a problem shooting military ammunition are the .223 owners with 1 in 14 or 1 in 12 twist barrels with shorter throats or leade designed for the lighter civilian bullets.

What you also will find is the older M16 clones don't like the new heavier ammunition and were taking a pounding due to higher gas port pressures and this is the major reason for the .223/5.56 NATO warning.

If you have some surplus military ammunition just shoot a few rounds and read your primers and cases for pressure signs. Again the SAAMI is "NOT" posting a catastrophic firearm failure warning, they are posting "posible" pressure related problems with short throated rifles.

Now go out and do your own research on the subject like I did and don't believe anything said in forums no matter how many 5 gal buckets of .223/5.56 ammo I have.

[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP6526.jpg[/img]
Yes, do you own research...and disregard this post as you search. The problem has to do with the space in the chamber. As the throat was lengthened on 5.56 ammo, so was the size of the chamber to make room for the bullet. This is not the case on .223 firearms. If this were not true then the 223 wylde chamber would have never been developed. Weapons are tested with ammunition lots that producing a minimum corrected mean chamber pressure, as stated by each group - either SAAMI or NATO EPVAT. The 5.56 rifles have actually been manufactured and tested according to these specs, whereas sporting rifles have been manufactured to pass the SAAMI specs. The simple statement that all Savages are strong enough to withstand pressures they were neither manufactured nor tested to withstand is a bit foolhardy. Just take a look at all of the manufacturing defects coming out of the Savage factory, as well as other gun makers, such as Remington. The thread below about the weather warriors with messed up receivers is just one example.

We all know that no two guns are exactly alike. I am glad to hear someone has been firing 5.56 without fear or problems in their 223, but that doesn't mean the next person who reads this and does the same will not have a problem. Sporting gun makers manufacture their guns according to SAAMI specs, and in the case of the .223 REM chamber, those specifications do not come close to achieving the allowable pressure specs of the companies who manufacture 5.56 ammo. This is about the same as someone asking if they can shoot 2-3/4" shells in their antique 2-9/16" chambered shotgun. Will it be okay? Probably, but for how long? The first time? The 100th time? The 1000th time?