After re-barrel :: 2 shots close together and 1 shot further out

[Lefty7mmstw]

ignition possibly?? what's happening with your velocity when the rifle spits into a second group... I'm seeing a bit of the two group crap with my pistol in 7-08 right now with one load.... I switched pills first, if that doesn't cure it I'm going to a hotter primer out of spite, then switching the entire load if that doesn't work...

btw., the barrel is about the only thing that actually creates accuracy in a rifle... everything else simply conspires to destroy it if not set up correctly. The new barrel is absolutely a new animal, and should be treated as though you have a different rifle than before.

 

[Mcranch]

Have you kept shooting it to see if there are two distinct groups? Two groups almost always means something is shifting back and forth. Given all that you have done I would bed the action and if a heavy varmint barrel I would also bed about 2 inches in front of the recoil lug. Then make sure the barrel is free floated. While at it I would install pillars as well. Making sure the action screws are centered and torqued.

I'm having a similar issue with a McMillan pillared stock for my Sako AV 25-06. Was told to torque to 45 inch lbs. the bolt was not smooth slight bind backed out on torque 3 inch lbs at a time until it was smooth on bolt no bind at 35 inch lbs. started groups around 3/4 moa. Next time out will back out to 30 and try that using 115 nos bt. Was told by McMillan that their stocks hold at minimum 20 inch pound.I'm in Fort Worth will consider beddin. Thanks

 

[sedancowboy]

If your bolt is binding when torqued to 45 in lbs then you need a new bedding job. A stress free bedding job should allow you to torque 55 +inch pounds with out any problems. I am not familar with Sako's so not sure what they spec.

 

[Stockbroker]

edit

 

[Stockbroker]

Have you kept shooting it to see if there are two distinct groups? Two groups almost always means something is shifting back and forth. Given all that you have done I would bed the action and if a heavy varmint barrel I would also bed about 2 inches in front of the recoil lug. Then make sure the barrel is free floated. While at it I would install pillars as well. Making sure the action screws are centered and torqued.

As sedancowboy says, I have seen/experienced similar. Nathan Foster calls it "double grouping" as a bedding/action stress issue. Dynamics have changed with your new barrel, as it sounds like its heavier than the OEM.

-W Chapman
Accurate Innovations

 

[nksmfamjp]

Have you kept shooting it to see if there are two distinct groups? Two groups almost always means something is shifting back and forth. Given all that you have done I would bed the action and if a heavy varmint barrel I would also bed about 2 inches in front of the recoil lug. Then make sure the barrel is free floated. While at it I would install pillars as well. Making sure the action screws are centered and torqued.

Can you bed those factory Tikka stocks?

 

[nksmfamjp]

Ooops

 

[Bdog35]

Is it possible for a new barrel to be the cause of 2 shots being VERY close together and a third shot being 1/2" to 3/4" apart? The shot that is "out" can be the 1st, 2nd, or 3rd shot.

This is on a Tikka T3 Varmint in 22-250 Rem. Using the original, factory stock. It use to shoot amazingly well.
Replaced the barrel with a Rem Varmint contour, 1:12 twist. Had to reduce the breach end to 1.150" to better match Tikka action.
I was hoping to use close to the same load that worked well in the original barrel so I had the gunsmith cut the finished length to match original barrel.

Things I've tried:
1. Different charge weights (OCW type of test)
2. Different seating depth of bullet
3. Open up barrel channel a little more.
4. Inspect bedding area and then overall stock for any crack.
5. Use a different, known good, scope
6. Use a different scope mount, (to remove the rail). Used the Tikka Optiloc rings and another different scope.
7. Try a different bullet

Have any of you seen a new barrel be the cause of such behavior?

Thanks -- Todd

Did you break it in? Shoot 1 clean it, then repeat the process 5 times. Shoot 3 then clean it?

 

[Greyfox]

Once your velocities stabilize(75-150 shots), I would re-test your original load. You may want to a OCW test. If the flier still persists, I would try a change in bullet then powder/ change......one variable at a time.

 

[arch408]

The old barrel shot "amazing well". Hmmmm?????

 

[RuninL8]

No, guessing here, I would bet you can go out, and cold bore shoot the gun and one hole. Meaning shoot once go in the house for 30 min and do the samething again and at the end of the day you would have a one hole group. Also, as mentioned by some else in this thread if you just kept shooting, you would end up with 2 groups. That is a bedding issue, you have 2 recoil points happening, meaning your recoil lug is not the only thing making contact during your shots, and whatever is heating up is able to get hot enough to do so on your third shot. How much did you free float, a dollar bill? Is it a wood stock or synthetic? Also, you have to be very careful with Tikka's because of the flat base of the action it is super easy get a secondary recoil point. There are ways of measuring action movement using a dial indicator with a magnetic base. PM me if your interesting in learning this procedure.

 

[skookum]

I had this problem with a 30 Nosler. During load development I would have two rounds in one hole and one flier. EVERY. ****. TIME. I tried everything. I was about to give up and as a hail Mary I tried 225gr eld-ms and RL 26. It started printing .3-.4 moa groups, but only with Bertram brass, it wouldn't shoot ADG. I have done load development for about a dozen rifles and it was by far the most difficult

 

[1snowcat]

So, I will offer a slight different opinion here... ( not saying it's right or wrong just play along) lets pretend for a second that you have no history with said rifle, forget how it shot before the re-barrel... Pretend that the gun is brand new and perfect smithing practices were used to spin up the new barrel.
NOW, have you run this load across a chronograph to see how much velocity variation you are getting shot to shot? If you have NOT done this I would FIRST and foremost, before worrying about anything related to the rifle build.
The reason I say this is just because it's the same length barrel and maybe even the same twist may not mean its the same actual speed of barrel, one or the other is faster or slower than the other. It boils down to harmonics your load might need tweaking slightly to preform better or worse than original barrel load combo it might not have a single thing to do with the actual rifle build but, just be the difference between barrels... I have seen guns shoot same 5 shot group one ragged hole with ZERO glass bedding and no crazy break in rituals just lucky load combos and good smithing, I've also seen exact same smith builds that won't shoot factory known loads you couldnt cover with a pie plate at 100 yrds from a bedded rifle... Out of curiousity what brand/weight bullet are you shooting in the 22-250? and what powder/ primer? it might be just a length issue or it could be a new load is required...

Dont get frustrated look at it like an adventure its always a good day at the range compared to working.
First thing I'd do is Chrongraph your load and post what the actual speeds are shot to shot... Im guessing there is more spread than you are thinking...I could be wrong, just an offer rather than chasing unknowns..

 

[robpiat]

I'm struggling with the 3 shot groups. I get why some people do them for load development and to preserve barrel life but since you are diagnosing an issue it definitely warrants going to 5. Then you can see if its 3+2, 4+1, or just a random pattern.