223 or 5.56

[alsaqr]

Sure the rifle can probably handle the higher pressure but actual pressure testing of 5.56 NATO ammo fired in a SAAMI .223 chamber resulted in pressures in the 85k range.

So says SAAMI. A friends Oehler Model 43 Personal Ballistics Lab says otherwise.

Strange that SAAMI waited until millions of rounds of surplus 5.56mm ammo hit the market to spring this big revelation on us.

This is the same SAAMI that asked OSHA to update the regs on small arms ammo manufacture, storage and shipment. Problem was that SAAMI did not contact US ammo makers first.

OSHA did as SAAMI asked. The proposed reg was put up for comments and US manufacturers of small arms ammo jumped all over SAAMI: SAAMI lied and whined to gunowners to pull their rears out of the fire.


Would SAAMI lie to you? IMO: The answer to that question is a resounding yes.

 

[bigedp51]

The real problem with the .223 and 5.56 NATO is anyone with two fingers and a computer can misinterpret what they read and post all the misinformation they want to.

1. There is "NO" practical difference in the chamber pressures in the .223 and 5.56 NATO. In the U.S. SAAMI chamber pressure is measured at approximately mid-cartridge case, the NATO EPVAT requirements measure chamber pressure at the neck of the cartridge which can make up to 20,000 psi difference in the "same" pressure reading taken at mid-case.

When the M-16 first came out it had the same twist rate and throat or leade as the .223. When the twist rate was changed and leade was changed on the M-16 for the longer heavier bullets is when the problems occurred in the interchangeability of the two types of ammunitions.

I have a Stevens 200 with a 1 in 9 twist and a longer throat and I can shoot either ammunition safely, the problem exists with the older .223 rifles with the shorter throat and 1 in 12 twist which can cause pressure spikes with the newer M-16 5.56 NATO ammunition. (END OF STORY)


5.56×45mm NATO
http://en.wikipedia.org/wiki/5.56×45mm_NATO

NATO EPVAT testing
http://en.wikipedia.org/wiki/NATO_EPVAT_testing

Do you really think your going to blow up the Remington 7615P Pump Action Police Patrol Rifle rifle shooting 5.56 NATO ammunition?



Below chamber and throat variables for the .223 and 5.56 NATO

 

[ugaarguy]

Do you really think your going to blow up the Remington 7615P Pump Action Police Patrol Rifle rifle shooting 5.56 NATO ammunition?

The 7615P has a 5.56 NATO chamber, so you'll be fine.

 

[OhioChief]

I was shooting 5.56 through my .223 for a long time because I had no idea there was a difference. Never had an issue, but I do wonder if you'd get less service life by doing so.