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Posted: 4/2/2007 3:51:18 PM EDT
Title pretty well says it all. I'm new to the M1A world and could use some input. Specs as follows: SA M1A 95 vintage , GI Gas cly unitized AMU style (screw and glue) by Huey Gunner: Sadlack op rod guide and Gas cly piston: GI barrel H&R 62 vintage: GI Fiberglass stock(black crinkle version supplied by SA) with selector cut out filled: TRW Bolt 1.632 headspace: TRW trigger group National match mod by Ted Brown: GI flash suppesor NM mod by Huey Gunner: Sadlack steel scope mount and 4-14 SA Scope: Am trying to work up some hand loads, but this thing will even string Federal GNM ammo. AL grouping done off the bench using front rest and rear bag. I suspect insuficent stock downward tension. I would appreciate any and all inputs. Thanks in advance for your time and consideration.
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yep you don't have your NPOA, thus you breathe and it goes up and down. guaranteed. |
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Vertical stringing is caused by changing harmonics on the barrel. As it heats up, pressure on the barrel changes, either from bedding or in this case, probably a gas cylinder/piston. The pressure will increase as the barrel gets hotter, causing the stinging. I don't believe it is shooter related. |
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