Early in the spring I bought a Bushmaster V-Match used from an individual.  It looks like new, not a blemish on it.  I bought a B-Square hi rise mount and put a 6-14 power Nikon Buckmaster scope on it.  
First day out to the range, it was amazing!  Shooting my 52 grain Sierra hpbt Match bullets in 1/4" groups.  I was thrilled...Same thing happened next time out to the range...Then things went SOUTH!
I am now getting about 1 inch groups with my reloads and up to 2" with Fed. Eagle 55 fmj factories.  I have tried several other factory loads and still over an inch @100yds.  
I cleaned barrel thoroughly and no improvement.  Tried changing to another scope, but results the same...
Any suggestions?
These same reloads yield 1/4" 100yd groups in my Savage Tactical.

Thanks
Swan hunter

Does it have a Flash suppresor or muzzle break?
If they loosen, accuracy will be affected.
Other items to consider:
Scope mounts.
Something causing improper lock up of bolt
Loose gas tube/block.
Heck I could guess all day and never get it right without seeing the rifle.

Try increasing your OAL a few thousands at a time. This helped on my RRA. First time to the range I got .5 MOA groups and it steadly increased no matter what I did with the powder charge. I think it maybe because as the throat wears you need to increase the OAL. Good luck!


EDITED to add;

I agree with gunslinger, loose or crappy scopes and/or mounts are probably the #1 cause of poor groups!

I don't know if this will help any, but I'd get a hold of tech support at Bushmaster.  I've got a 16" VMatch and the thing is a tack driver (for that genre of rifle).

BM's Tech Support guys have (with other issues) treated me like royalty, for what that's worth.  I'll bet they'd work with you because I get the distinct impression that they are very sensitive about making their custome's satisfied with their "babies."

Just a thought?

hey fed-up just wondering what ammo your v- match shoots best.best i can do is 1" at 100 with wal mart 45 gr. win. varmint ammo..thanks..