Thanks, I asked only to try to help cuz we all speak our own language and I've found out the hard way that I'm prone to assume too much about what the person's intent was.
So, both scoped and irons at 200 yards and about a 5" group with 10 shots. I assume that was the 168gr ammo?
No. that was 147 gr Dag. 168 smbt would have been worse.
Any time you are troubleshooting accuracy issues you need to return to the basics and look at three areas;
- The rifle
- The ammo
- The shooter
Since you said that there wasn't a lot of difference between irons and scope I would assume (that just might be the death of me yet) that the rifle isn't really the problem. If it were then you should always get the unacceptable groups regardless of ammo or anything else. The ammo is widely accepted as the gold standard to test against so we can assume that it isn't the problem so that only leaves one thing...please don't be offended I don't mean to insult anybody, I'm just trying to help troubleshoot something that most people have great success with and isn't working in this instance.
You mentioned a front rest, what part of the fore end of the rifle was on the rest? You will always get your best accuracy if you place the rest somewhere between just forward of the magazine and the just behind the front sling swivel. Anything farther back...well that's obvious, and anywhere forward of the front sling swivel and you tend to push the barrel around while you are shooting.
The rest was btween front swivel and Mag. inaccuracy Did you use a sling?
No sling
[*]The hand guard was touching the stock and the front band to the point of being jammed tight.
HG is releived and frnt. band and ferule are reamed.
[*]The front band was touching the gas cylinder.
No
[*]The op rod was dinging the receiver on the right side just about where the receiver ring is (the chamber opening).
Op rod is perfectly aligned and strikes the piston squarely.
[*]There was no stock liner, just molded plastic and the receiver fit loosely.
It's tight
Receiver and trigger group are tight in the stock
The only things that I can think of that could interact with different bullet weights are the twist rate (1:11 should be golden for the 168s), the free bore length in the barrel (different bullet weights usually result in different bullet lengths and that results in different distances for the bullet to jump to the lands). Maybe try a 175gr load and see what happens.
Tried 100 rounds of M-118 175 gr. Miserable results.
Heavier bullets should, theoretically, perform better at longer distances than lighter bullets, and they usually do. So if the 175gr works and the 168gr doesn't then there is something really quirky with the chamber. If the 175gr doesn't work then it seems like all heavier/longer bullets don't work well and then I would still be worried that there is something wrong in the chamber.
And finally, if you have never shot an M1A before
USMC 1968 M-14 Sharpshooter
and if you have far more experience with pistols
Admittedly, my discipline is handgun.
then there will definitely be a learning curve. I used to shoot pistols a lot (like 500 rounds per week for several years through semi autos and single actions) so I know that while you can be very good with a pistol, you need just as much practice with a rifle to be good and the M1A takes just a little more practice to get used to the old wood and iron style.
Good luck, and I hope you solve this one cuz it's nice to shoot tight groups with these rifle and impress the other guys on the range. DI5
