Sugestions for a Sick Rifle

[Rtheurer]

Gentleman.
I have a rifle doing some weird stuff. Looking for some advice or ideas on what to try or look at.
Some Info:
Rifle is NOT a bench rest rifle. Its set up for NRA Prone Long Range out of a Sling.
Action is a Early Stiller Predator Long Action Single shot.
Trigger CG Model 21 Two Stage.
Barrel. Kreiger 6.5mm 4 Groove, 1:8 Twist 31" finish, Medium Palma contour, Chambered in 6.5X284 ( My PTG reamer and gages) Currently has 330 rounds on new barrel
Masterclass stock copy of the H&H prone, Anschutz by Alex Sitmen.
Satern, Extended Picitiny Rail with Redfeild Base.
Leupold FX30, QRW rings,
Lapua Brass. 3X fired, Annealed, 140 gr Berger BTLR

Symptons.
Shoots 1/2MOA Elevation for about ten rounds or so then it goes bat shit crazy. Seems like to me that about the time the rifle starts to get hot or warm...then it just goes to shit shooting 2MOA. This Rifle has always shot very well. I have owned it for about 12 years and its had about 8 Barrels on it so far.

1st thought: Bedding: Its been a long time since new but looks very good with no Obvious signs of damage.

LOad? It shot good before at 600yds. Why now at 1000yds it goes to shit.? With in a couple tenths of a grain from the same load on the last twin barrel to this one ( got two at the same time) that I won the TN State Championship with last fall.

Kinda at a loss and very frustrated.

 

[clowdis]

It's probably not your bedding unless you have something under or alongside your recoil lug and the action isn't sitting snug in the bedding. Normally bad bedding will show itself as occasional shots off call or one or two shots out of a five shot group that are out of the group. Just solved a problem with a Barnard Palma where the back edge of the action was bedded and causing the rifle to shift point of aim in the middle of a string as it shifted from the back of the action acting as the recoil lug to the actual recoil lug working (no bedding block). Make sure your action bolts are clear and not hitting anything. Just because you bought two barrels at the same time doesn't mean they're from the same lot of steel. It sounds like the steel may have some residual stress in it and may benefit from stress relieving (cryo treating). If everything is the same as it was before and the only thing changed is the barrel then I'd look there for the problem. All barrels aren't created equal.

 

[rayjay]

Throw the old bbl back on it.

 

[gme]

Russ, are you seeing much copper fouling?

 

[Rtheurer]

No Gary not much Copper at all. Nothing out of the ordinary.

I just pulled the stock off and found some Solvent or light Oil between the Action and bedding up front by the action screw and recoil lug area. I sure hope that was it. But why would it shoot good for ten or 15 rounds then go crazy?

 

[DaveTooley]

As rayjay suggested. Put the old barrel back on and do a quick test. I've done battle with rifles for several seasons after a barrel change. I put another barrel on and knew in 20 rounds the rifle was shooting well.

 

[FatBoy]

Just give that POS to me, Russ. I don't shoot well enough to know the difference anyway.