Sign Rifle Needs Bedding

[luke5678]

I was wondering what signs are of a rifle needing bedding? I am getting inconsistent performance from my rifle after each barrel cleaning (have to re-zero).

I have a remington sendero 7mm Mag. Shot great until recently. Also, how many rounds should the barrel take before it needs to be replaced?

Thank you.

 

[squirrelduster]

Sounds like something is loose in the scope mounting or scope.
Does the zero hold after you rezero it?
What kind of loads are you shooting?
Are the loads using the same lots of components as before?

 

[baldhunter]

I agree with above.Check your action screws,take your scope completely off,check your bases,remount your scope and see if anything changes.When you sight your rifle back in,if adjustment don't go the way you move it,it could be a problem with your scope too.Give your barrel a good cleaning,shoot some ammo that you know shoots well in your rifle and see if any of that helps.I do bed the recoil lug on my Senderos.That aluminum bedding block does a good job at supporting the bottom of the action,but the inletting for the recoil lug can be a little sloppy for my liking.I would consider bedding the lug,it sure won't hurt.

 

[FEENIX]

I have a remington sendero 7mm Mag. Shot great until recently. Also, how many rounds should the barrel take before it needs to be replaced?

Try Excel Formula Predicts Useful Barrel Life within AccurateShooter.com

 

[johnnyk]

"I am getting inconsistent performance from my rifle after each barrel cleaning (have to re-zero)."

This statement makes me suspicious that what you are seeing is normal "point of impact" (POI) movement of the bullet after cleanging. If there is oil or solvent residue left in the barrel, and there invariably always is, this will cause the first shot (or more) to fly off course. If the rifle is solid (i.e., action screws tight, barrel not touching, consistent trigger) then it should settle down and return to it original zero (or POI) after the barrel is slightly fouled. My rifles usually like at least one fouling shot and then they're back in their groove(s).
I may be way off base. You are using the same ammo each time, correct? Do you give the rifle time to "settle" down after cleaning the barrel? JohnnyK.

 

[luke5678]

Yes, once I rezero it does hold until I clean the barrel. Then my zero changes (within an inch or so) and I have to adjust nightforce scope and then I can put the next 20 in 1/2 inch group.

Then the cycle starts over again. I clean the barrel. Shot 3 fouling shots, then I put the next 20 in a different place then before.

That is what makes me think it's not the scope or mounts because the only thing changing is cleaning my barrel.

The rifle used to not do this, a recent change. The only thing that changed was that I started de-burring my flash holes this last time and it shot 1.25 inch higher than before. I don't see how that can make much of a difference. I shoot handloads (60.5 g. of IMR4350, 3.345OAL, CCI Mag primer, nosler brass, 160 accubonds). All sorted and weighed. This load is proven over the past year in the gun for 1/2 inch at 100.

I have about 400 shots through the gun so I don't see how I could have shot it out. I recently had a gunsmith go through the gun too and he didn't see anything too wrong with it. He said it's not straight (action-barrel) but said that is normal for a remington.

Any help is appreciated.

Thanks

 

[Buano]

I would likely test the security of the scope before doing anything. Shoot 4-5 rounds then hit your scope with the heel of your hand & see is zero shifts.

Assuming your action screws are torqued properly, my next thought would go to lapping your lugs. When you clean the gun you remove the bolt. If it's not stable you could see minor differences in p.o.i. — especially with the action out of line with the bore. I would suggest having the action trued, lugs lapped & recoil lug bedded.

Scopes do go bad & mounts do work lose, not often with quality parts, but it does happen. I second the suggestion you remove the scope & mount, then reinstall each.

 

[rscott5028]

Check that everything is secure as stated above.

Then load 20 from one consistent batch of brass...
- Shoot 5 for group
- Put it away and come back another day without cleaning
- Shoot 5 for group

save your targets including notes on shooting conditions

do this 4 times until all 20 are fired

Are the groups consistently sub-MOA?

Is the POI consistent (accounting for wind) without cleaning each day?

Repeat the above procedure until your groups open up.

Too many changes too fast will cause you a lot of grief.

 

[Buano]

Check that everything is secure as stated above.

Then load 20 from one consistent batch of brass...
- Shoot 5 for group
- Put it away and come back another day without cleaning
- Shoot 5 for group

save your targets including notes on shooting conditions

do this 4 times until all 20 are fired

Are the groups consistently sub-MOA?

Is the POI consistent (accounting for wind) without cleaning each day?

Repeat the above procedure until your groups open up.

Too many changes too fast will cause you a lot of grief.

I feel like an idiot for not having suggested that first! Environmental changes will change point of impact, even at 100 yards!

 

[luke5678]

Good idea. I was shooting with a 10-12 mph to my back. Would that float my bullet 1.25 inches higher at 100 yards than two days earlier when I had a slight cross wind? It was 35-40 degrees cooler the day it was shotting 1.25 higher than the other as well.

Friday: slight cross wind and 65 degrees outside. Put 10 shots in and around the bulleye within .75 inches.

Sunday: 10-12 mph wind to back and 30 degrees outside. Put 7 shots 1.25 inches higher than Friday. Barrel was cleaned on Saturday.

Would this make a difference? The only other change was deburring the flashholes...

 

[rscott5028]

All of those things can certainly affect POI to a greater or lesser degree. Even simple things such as bipod one day and bench rest another make a difference.

The only way I can tell if I make progress is to measure everything and make copious notes.

That way you have a well established baseline to determine if a particular change such as a particular cleaning technique or bedding the action makes a difference or not and to what degree it helps or hurts.

 

[luke5678]

Thank you for your help.. I'll keep shooting it (keeping notes) and see how it goes...

 

[elkaholic]

Thank you for your help.. I'll keep shooting it (keeping notes) and see how it goes...

It is true that many of the things mentioned can affect POI but there is one thing that is consistent. If your POI changes EVERY time you clean, I can just about guarantee you that you do not have a problem. I say that because 90% of rifles out there will change POI to some degree. It may be slight, and and may be as much as 2-3 inches. The best indicator is, does it move to the SAME POI after you clean and then come back to the same POI after a few rounds? I don't remember the last rifle I've had that didn't do that to some degree. It is simply the difference between clean and slightly fouled. When it gets to severely fouled, the same thing happens and accuracy goes south as well. When you clean try to be consistent. I like to remove ALL of the carbon residue and leave a SLIGHT amount of copper fouling. In otherwords, don't try to clean until there is absolutely NO sign of blue or green on the patch. This will only cause you to take more fouling shots before your POI settles back in. Every barrel, regardless of the quality and amount of lapping, still has imperfections (pores). until those are filled with copper, the POI will be affected. I hope this makes sense? Try it and see. Good luck....Rich