Need help! Just to much information out there on 308 vs. 7.62
Posted October 23rd, 2011 at 06:48 PM by helo
Well guy's I finally have my M1A, but with it comes many questions that I was not aware of Ammo (308 vs 7.62). Can anyone help me as to what I can use as far as commercial ammo and the preferred brass? Helo
Total Comments 3
Comments
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Look at your barrel, it will be stamped either .308 Winchester or 7.62x51mm; use the ammo that matches the stamp.
As for the .308 vs 7.62 question, search Larry Gibson's or my posts, we had a couple of detailed discussions about the topic.
The bottom line is;- There is very little or no difference between the ammo but there are differences between how the chamber is cut. Therefore, if you want the best reliability, the comment in my first paragraph applies.
- Chamber pressures for the most common .308 and 7.62 cartridges average about 53000 PSI, there isn't really any difference between the two. The old wives tale that 50000 PSI is max pressure is wrong. This is a misconception caused by the military using the wrong unit of measure when they printed their pressure standard. They used PSI when it was actually a CUP unit of measure. SAAMI shows both units of pressure, and the 50000 CUP value is very close to 62000 PSI.
- There are no 7.62x51mm sizing dies, they are all .308 Win; that means that all ammo built in the U.S. conforms to .308 Win dimensions, including our military ammo...at least dimensionally.
- SAAMI National Safety specs indicate that the two are interchangeable.
- While most military surplus ammo will normally work in your rifle some wont due to quality control issues and the fact that they are Military Surplus. Military surplus is sold to the public because it either doesn't meet manufacturing specs, shipping specs, or storage specs. Any of those could mean that the ammo wont work properly.
- Commercial .308 cartridges up to about 180 grains will work well in the rifle. I don't recommend the 175 grains or above as steady fodder because they pound the rifle pretty hard, 168 grains is the commonly agreed heavy bullet. Do not use the new maximim or magnum loads, they haven't been tested enough in the real world for me to recommend them. Don't use the soft lead tipped hunting bullets, some are too soft and if the lead tip breaks off it might get jammed someplace that could cause mechanical problems.
That's it in a nut shell.Posted October 29th, 2011 at 11:30 AM by RAMMAC
- Great post,
yes the 308 is the best ammo and rifle to use for best accuracy use Black hills match or Federal 168 match ammo, the 7.62 is for the most part a 30-06 i bit larger casePosted November 25th, 2011 at 03:18 PM by remmington 700 -
Thanks for the information, its clears up a few questions I had on ammo differences.Posted November 27th, 2011 at 06:07 PM by Mr B
