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Rifles, Reloading, Optics, Equipment
Reloading
2 dumb questions
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<blockquote data-quote="Bart B" data-source="post: 609951" data-attributes="member: 5302"><p>You're almost right. It wasn't the hot loads (those above SAAMI and MIL SPEC limits) that caused the problems. It was too slow of a powder that made the port pressure too high and bent their op rods.</p><p></p><p>Both the US Army and USMC rifle teams pulled the 172-gr. bullet from M118 match ammo and replaced it with a Sierra 180 HPMK for use in their M14NM rifles. While that handload put peak pressures up about 10% over normal max, no problems were found.</p><p></p><p>And the US Air Force and Navy rifle teams removed the bullet and powder from M118 match ammo then put in 44 grains of IMR4320 under a Sierra 190 HPMK for their M1's converted to 7.62 NATO. That load was about 15% over normal max, but none of their Garands suffered in the least.</p><p></p><p>All the service teams pulled the 147-gr. bullet from certain lots of M80 ball ammo that was loaded by Lake City Army Ammunition Plant with IMR4475 powder then replaced it with either a Sierra 168 or M2 172-gr. match bullet. Both of these handloads had peak pressures about the same as the 7.62 NATO proof load around 66,000 CUP in both M1 and M14NM rifles. Again, no problems were noted.</p><p></p><p>That info's well known by lots of folks. Too bad Sierra doesn't mention the thousands of .308 190-gr. HPMK's they sold to the military teams shooting them over IMR4320 in Garands.</p><p></p><p>AR-10's shoot bullets just as fast as M14, M1A or M1 rifles chambered for the .308 Win or 7.62 NATO round with the same length barrels. They never had a problem shooting match winning and record setting scores at 1000 yards. That is, as long as they didn't use the M852 match round shooting Sierra 168's in a near worn out or oversize bore...or use a barrel less than 22 inches long.</p></blockquote><p></p>
[QUOTE="Bart B, post: 609951, member: 5302"] You're almost right. It wasn't the hot loads (those above SAAMI and MIL SPEC limits) that caused the problems. It was too slow of a powder that made the port pressure too high and bent their op rods. Both the US Army and USMC rifle teams pulled the 172-gr. bullet from M118 match ammo and replaced it with a Sierra 180 HPMK for use in their M14NM rifles. While that handload put peak pressures up about 10% over normal max, no problems were found. And the US Air Force and Navy rifle teams removed the bullet and powder from M118 match ammo then put in 44 grains of IMR4320 under a Sierra 190 HPMK for their M1's converted to 7.62 NATO. That load was about 15% over normal max, but none of their Garands suffered in the least. All the service teams pulled the 147-gr. bullet from certain lots of M80 ball ammo that was loaded by Lake City Army Ammunition Plant with IMR4475 powder then replaced it with either a Sierra 168 or M2 172-gr. match bullet. Both of these handloads had peak pressures about the same as the 7.62 NATO proof load around 66,000 CUP in both M1 and M14NM rifles. Again, no problems were noted. That info's well known by lots of folks. Too bad Sierra doesn't mention the thousands of .308 190-gr. HPMK's they sold to the military teams shooting them over IMR4320 in Garands. AR-10's shoot bullets just as fast as M14, M1A or M1 rifles chambered for the .308 Win or 7.62 NATO round with the same length barrels. They never had a problem shooting match winning and record setting scores at 1000 yards. That is, as long as they didn't use the M852 match round shooting Sierra 168's in a near worn out or oversize bore...or use a barrel less than 22 inches long. [/QUOTE]
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Reloading
2 dumb questions
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