Savage barrel stress spot?

[SavageStag]

I am at a loss so I was hoping someone here might have an idea as to what's causing my problem.

As my barrel heats up (like 3 or 4 rounds) there is a drastic shift in POI. I noticed this problem a while ago but blamed it on my 162gr A-max factory loads. It shoots really good at 100 and the change in POI just must be that much more noticeable at 300yds. So I switched to some Rem Premium 168 SMK's and the problem has persisted.

The gun is a 10fp glass bedded into a B&C Medalist from the tang up to and including the barrel nut. (no idea why the smith bedded that too) The barrel is completely free floated to the nut. I have had two different NF and rings on it so I know it isn't the scope or rings. If it didn't shoot so well for the first few rounds I would blame myself, and while I am no expert, I certainly don't suck this bad. Any help or suggestions would be greatly appreciated!

Here is a typical 300yd target, it's obvious where the first 3 shots are. The closest to the center was the cold bore shot.

 

[badbot]

Re: Savage barrel stress spot?

did it shoot before the bedding job?
how do you torque the action screws?
I assume nothing is loose on the scope & mounts.

 

[SavageStag]

Re: Savage barrel stress spot?

I never measured groups before the bedding job past 100. I just shot steel and never walked out to see how it was grouping.

For the action screws, I just tighten them down with a allen wrench. I never used a torque wrench, but I didn't crank them either. I will check those but i kinda doubt it would have this effect. I would think it would shoot bad the whole time if that was the problem...

 

[FequalsMA]

Re: Savage barrel stress spot?

The thing with factory barrels is the fact that you sometimes run into a lemon. The bore is not perfectly straight as one would like to think. An extreemly exagerated example would be to imagine a snake in a pipe. The snake being the bore. When the barrel heats up the node will shift dramatically if the is the bore is not straight in relation to any metal stress.

This may not be the case so make sure you double check all other posobilities before you write off the barrel.

 

[cavscout1983]

Re: Savage barrel stress spot?

He bedded the tang? You're not supposed to bed those on a Savage as there is no secured contact point there. Only on an action where the rear screw goes into the tang is that necessary. When you leave it free floated, it induces less stress on the bedding.

What about the B&C...I had one on a Rem LTR and I had to dremel down the bolt handle channel because it wasn't allowing consistent lug contact. Not sure why that would effect a savage with the floating bolt head but I suppose it could effect it depending on the severity.

When you are tightening the action screws- are you tightening the front first with buttstock on the floor?

You should really check with a torque wrench. Even hand tight can be tighter than we realize.

Do you still have the original stock? If so, throw the barreled action in there and look for a POI shift that mimics your current one. If that happens- it *shouldn't* be anything to do with the stock/bedding. If not, you need to start looking at the stock/bedding. First step would be to properly torque everything. 2nd to relieve the bedding in the tang area ( look at a savage bedding thread to see where to stop).

If that doesn't fix it, I have no idea.

 

[cavscout1983]

Re: Savage barrel stress spot?

Also, aside from bedding.. have you had anything else done to the rifle? muzzle brake, etc?

Reason I ask is I had a brake done up for the LTR and asked the smith to leave the bottom of it solid ( his design was similar to a VAIS), and between a broken IOR, the bolt handle channel, and the brake- I was chasing my tail for months.

Fixed the IOR with a USO, so knew that wasn't the issue. Fixed the lug issue due to a friend having had the same issue on one of his B&C stocks, and still was shooting patterns that confounded me (like... 8MOA). Finally asked 9H to shoot it and he was having bad luck so I finally concluded I wasn't the issue. He decided to remove the brake and we had an insane amount of deviation from zero w/ brake. But! As soon as he removed it and re-zeroed...we backed up to 400 and he proceeded to put a very nice sub-MOA group on steel with a smattering of ammo. Everything from m118LR to FGMM 168gr to hand loaded 175gr SMK. something like 6 shots and all in one sub-MOA group, repeatable POA/POI.

Just goes to show how something seemingly innocuous can ruin a few months of shooting.

 

[SavageStag]

Re: Savage barrel stress spot?

Thanks for all the suggestions guys, I have checked everything out and of course everything checked good. I'm debating removing some of the bedding around the nut so that it is also free floated.

Is it common practice to bed the nut as well?

 

[cavscout1983]

Re: Savage barrel stress spot?

I'm not sure about the bedding of the nut... I'd hold off on removing anything until someone else verifies the accuracy of my posts with their own experiences.

I've never bedded a Savage and the only time I had the remington done, I took it to a smith since I wasn't confident in my ability to not mangle the process beyond belief. I try to avoid my signature line as much as possible.

 

[Qld4390]

Re: Savage barrel stress spot?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SavageStag</div><div class="ubbcode-body">Thanks for all the suggestions guys, I have checked everything out and of course everything checked good. I'm debating removing some of the bedding around the nut so that it is also free floated.

Is it common practice to bed the nut as well? </div></div>

I just finished bedding my Savage 12 build in an HS stock. From all the searching I did, I decided NOT to bed the barrel nut, or the rear tang. If it were my rig, I would float those two areas, and retest the accuracy. Worst case is you've wasted some time and haven't gained any more consistency.

 

[Kells81]

Re: Savage barrel stress spot?

I have a savage 243 that does this in a bad way. I have had it since high school and killed a bunch of deer with it though. 5 shots its good to go, anything past that it looks like its hitchhiking left and down. At least its consistent though and does it every time.

I figured it to be the barrel heating up and causing POI shift. After it cools it back in the right place.

 

[SavageStag]

Re: Savage barrel stress spot?

I've decided to take the bedding out from under the barrel nut.
I figure if I end up having to buy a new barrel I'll have to do it anyway. Hopefully it isn't raining this weekend so I can go see if it helps at all.