My neighbor and I went to the range yesterday. He's got an M1A that has always given him problems. Thing is, it just doesn't want to print consistently. He's checked a number of things, found a few things that need tightening occasionally, but it's still not right. Groups look more like shotgun patterns; no consistency at all.

I know it's not him because he can get nice groups with his Garand.

BTW, I think the M1A used a Federal Ordnance receiver and a Springfield muzzle break, but beyond that I have no idea of the rifle's makeup.

Any ideas on what he should check for? (I suggested for him to take it to a 'smith and have an expert in M1As give it a going-over.) TIA

Get a good bore light and see if the chrome lineing is flaking (if it has one).  Check the crown, inside of the flash suppressor/brake for copper (bullet making contact), front sight tight, castle nut tight (and the little screw that keeps the nut in place), rear sight tight, stock to trigger assembly/receiver fit tight.  Just a few things I would check.

My standard loaded M1A with GI refinished stock had wandering zero problems. Was grouping 2.5" (Federal 168 match), but was not putting them in the same place.
So off to my gunsmith (gruningprecision.com) for the accuracy package (bedding, unitizing, etc.) Now it puts 5 rounds into 1.25" on average with the CA muzzle brake (seemed to shoot a little better with the national match flash hider). Shot a 192 at 600 yards, and I am not a service rifle high power shooter.
The receiver must have been swimming around in the stock.

Good luck with yours.

Long Range

take the trigger group out of the stock, then try to move the receiver left/right/front/rear in the stock.  If there is any movement at all, the rifle will shoot like crap even if you have ALL the other match modifications.

Adding on the above, how hard is it to close the triggerguard?  If it closes easily, he has a loose stock.  Bed it or get a USGI synthetic.

ETA: more tips here

I had a SA Inc muzzle break that kept my M1A from grouping... solved that by installing a GI FS.....

If he's fired the weapon alot, it could just be simple excessive fouling in the bore.  Maybe a good scrubbing will straighten it out.