I have an HS Precision pro hunter in .375 RUM. It always shot like a million. This season, getting ready for a trip, major problems. It's shooting quite erratically, up to dinner plates at 200 yards. I've changed scopes, mounts, and re-torqued the bedding screws to the factory recommended 65 inch lbs.
The last rounds fired at 100 yards resulted in 6 in a one inch group, with 4 scattered about 3 inches right.
I've also cleaned the bore well.
Any thoughts?

Is the bore okay? Rifling okay? That's pretty strange, but if there's even a small defect in the bore it could cause that to happen.

Also, I know it's an elementary question, but are you using the exactly same ammunition you were before?

How's the crown? A dinged or messed up crown will not enhance accuracy.

Shooting Remington factory ammo, 300gr A-frames. Same as before. The rifle has had maybe 250 rounds through it since I bought it 5 years ago. The bore grossly looks OK, hasn't been inspected with a bore scope. The rifle is equipped with a factory muzzle brake. The crown looks fine grossly.
I will likely be sending it back to HS precision tomorrow after I call them. Hopefully to be corrected and back to me before leaving for RSA and Zimbabwe 5/25.

Cracked stock between the mag box & the trigger maybe.

I would pull it from the stock and check for cracks. Then when you have it out glass bed it.

These sorts of problems drive you mad!

I have just gone through 90 rounds of 7x57 trying to work out why my previously 0.5moa rifle went 2moa. It shot 2 together and one flier.

Finally I changed the scope and mounts and got 0.5 moa for 2 groups straight off.

Your problems sounds like scope or mounts to me - even though you've changed the scope. Are the mounts OK?

Try a different scope before you attempt any other solution.

AD

I would be willing to bet it is a fouled bore. You say clean and borescoped but really, if it is copper fouled then it is the problem. Also, make sure it is the shooter and not the gun; you may be starting to get a little apprehensive when you touch one off. Ask a known shooter to try it.

quote:

Originally posted by Marty:
Shooting Remington factory ammo, 300gr A-frames. Same as before.

Same ammo? Same lot # ? /same case/box of ammo?? I'd suspect Remington ammo before I'd suspect the rifle!!

Thanks for all your thoughts. To respond to a few questions-
Started with the same lot number the rifle had shot moa until I ran out and ordered new. Hadn't shot the gun since Africa 2 years ago.

Same problem with two scopes- a Kahles 1.5-6 and IOR Bucuresti 2.5-10. I had converted to Talley detachables, and when the problem became apparant, Dave Talley micked a new set personally and sent them to me at his expense Fed-Ex to be sure they had not created the condition. Same results. Dave is a prince.

Spoke to Dave at HS precision who said I should take the rifle to a smith and retorque the bedding screws to 65 inch-lbs. Whe neither smith in town had a wrench, I bought one and made the sdjustment. No improvement.

Shot it with and without the muzzle brake, off bags and a lead sled, no change.

Had My brother-in-law (former 100 yard match shooter, loader and grest shot fire a group. Same results.

Cleaned the bore multiple times with Extreme Coppermelt, feel all fouling was removed. Same results.

I sent it off to the factory today.

Sorry, that should have read 1000 yard match shooter, not 100!

quote:

Originally posted by Marty:
Sorry, that should have read 1000 yard match shooter, not 100!

Well. let us know what happens, and what the problem turned out to be.

Just got the gun back from HS Precision. Apparantly, it was fired with the brake not on tight at some point, resulting in bullet strikes at the end. HS has repaired, at no cost to me I might add, switched out the magazine which was binding a bit, and repaired a broken sling swivel all at no charge, and shipped it home at their expense! I am very impressed with the customer service. Dave was wonderful to deal with over the phone, having to deal with the panicky calls from a man leaving for Zimbabwe 5/25!
I had tried firing without the brake, but perhaps at that point my shooting was deteriorating from fatigue, frustration, whatever. I still need to test fire, maybe Wednsday.