Another thing I just thought of and not sure how much of an accuracy issue it creates. There is a difference between 7.62 Nato and .308. Both have very slight different headspace specs. And the book chamber pressures are different between the two. If you have not already figured that into what ammo you have tried, you could look at what your gun is chambered specifically for and see if using commercial .308 in a 7.62 Nato chambered gun or vise versa could be presenting an accuracy issue.

Obviously you would want to rule out the obvious or easy fixes before going to something like bedding a stock. Do you have a wooden stock? Which would be more prone to warp. If so, you could try a synthetic stock to see what happens.

The national match is already bedded and has extensive work done. Don't send it to a smith!

I'd let someone else shoot it with good ammo and if it still doesn't group, send it back. SA's customer service is very good.

I can clerify a few things.

He has the M1a Loaded acording to his post, this is a base rifle with NM sights and barrel. Stock should not be bedded and if it was its not now since he has swapped them around.

Honestly this is a list of things I would check first.

Synthetic stock on. If not put it on.
Make sure its torqued to specs, call springfield and find them.
Make sure your mount is torqued to spec.
Make sure your rings and scope is properly mounted.

Toss the Springfield Armory scope, there junk and it could be your problem more than anything at this point. Belive it or not your scope can jump around causing your issues but generally you would notice if this is the case because you will have random flyers.

Trigger needs to be adjusted, from the factory there horrible.

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Now some questions what range are you shooting ?
From a bench ? Standing or Prone ?

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I will be honest, I have fired both the M21 SWS and the XM25 whitefeather. Both of those are 3-4 times more in price and attention paid to them and I was lucky to get MOA at a hundred yards. So while you should be getting better than 3MOA you should realisticly expect 1.24-1.75 MOA

I can clerify a few things.

He has the M1a Loaded acording to his post, this is a base rifle with NM sights and barrel. Stock should not be bedded and if it was its not now since he has swapped them around.

Honestly this is a list of things I would check first.

Synthetic stock on. If not put it on.
Make sure its torqued to specs, call springfield and find them.
Make sure your mount is torqued to spec.
Make sure your rings and scope is properly mounted.

Toss the Springfield Armory scope, there junk and it could be your problem more than anything at this point. Belive it or not your scope can jump around causing your issues but generally you would notice if this is the case because you will have random flyers.

Trigger needs to be adjusted, from the factory there horrible.

-

Now some questions what range are you shooting ?
From a bench ? Standing or Prone ?

-

I will be honest, I have fired both the M21 SWS and the XM25 whitefeather. Both of those are 3-4 times more in price and attention paid to them and I was lucky to get MOA at a hundred yards. So while you should be getting better than 3MOA you should realisticly expect 1.24-1.75 MOA

Didn't know it was possible to torque an M1A stock??? Im shooting of of a bench with sandbags front and rear at 100 yards. I have also shot it with a Nikon monarch scope with no change in accuracy. I realize that M1A's are not the most accurate rifle in the world (especially the loaded version) but I am just wondering if anyone on here knows any tricks to tune them up a little? Also, it has a NM trigger group from the factory. Do those need to be tuned up too? I am thinking a lot of the problem may be the Gen 3 mount being that I can hold better groups with the iron sights at 100 yards than with the scope.

What on the JAE-100?

the best M1A stock in my opinion http://www.jallenenterprises.com/