Range Report Serious cold bore shift.

[JakeM]

So last week I took my tikka out to 600yd and fired 10 shots. I did not touch the elevation or windage after the initial correction. And this is what happened. Disregard holes that are marked.

Shot one, two and three are off the paper and then it goes up and left, I was shooting at the white center with orange circle. I dialed up 18 moa and then shot my ten rounds, I’ve noticed this gun likes to settle in after the barrel is hot. Anybody got an idea of what might be going on? I’ll shoot 20 rounds late when the wind dies down to see if it does the same thing. I have noticed slight changes at 100yd with cold bore vs hot bore shift.

The odd shaped hole is from the bullet hitting the metal rod I had help hold up the target, and the one at the bottom corner is from a tack I had hold the paper.

 

[Quicksilver338]

Is this your first time testing at 600yds? What were wind conditions? Mirage? Scope being used? Factory barrel? What Bullet/load?

 

[JakeM]

With this rifle yes. Little to no wind only shot without wind. Yes there was mirage, I shot on 9 mag. Nightforce nxs 5.5-22x56 npr-1 reticle. Factory 20” ctr barrel. 308 175gr smk 39.5gr imr4064, muzzle velocity 2,345fps.

 

[Quicksilver338]

My favorite reticle! Do you think at only 9x magnification you could have been slightly off on your holds? Also that is moving very slow for a 175gr bullet. My brothers 20” tikka tactical had them going 2620fps with varget.

 

[JakeM]

It’s slow because that is the accuracy load. I held center center every time. I think it’s just the gun likes being hot.

 

[Quicksilver338]

I’ve never had a gun shift impact with cold or hot. Being a CTR with a slightly heavier barrel I doubt it even more. I’ve seen groups open up with pencil hunting barrels after getting hot but they didn’t walk up the target like that. Also how high did you load before you saw pressure?

 

[JakeM]

I didn’t see any pressure I went up 41.5gr.

 

[Dthomas3523]

Document at 100yds. Verify there is an actual shift. Have other shooters you trust shoot it and document shift with them as well.

Then start looking for anything loose. Any screws.

Check and make sure the stock is not touching barrel or flexing under pressure from bipod loading.

If all that is cleared up and still a shift, put another optic on it.

If there is still a shift after that, you likely got a barrel with a bad heat treat

 

[Reload10]

Do a "cold bore" test. Every day take it out and fire one shot after multiple dry fires. If those truly do deviate from a "warm bore" than it is true cold bore issues.

 

[JakeM]

Ok three groups at 100yds.

Because I had to go down one minute after group one I got to messing-around with the zero stop and while undoing it so I could go down I incidentally clicked the scope. Shot round one of group two and adjusted up one moa. Then shot group three without adjusting anything. I think the cold bore goes left and as the barrel and ammo heated up at 600 the other day my velocity speeded up accounting for the rise.

 

[Dthomas3523]

With those groups, I’d focus on the shooter or load development before I’d try to verify a mechanical problem.

Unless you shoot other rifles and it doesn’t look anything like that.

 

[JakeM]

This is from load development. I’ll clean it and shoot again to check without messing with the zero.

 

[Lowlight]

Ya, this isn't a "Cold bore" issue,

It's more shooter and maybe a few other things mixed in,

The issues are distance are the key, group size is never linear, meaning if you shoot 1/2 MOA at 100 you are not shooting a 3" group at 600, you probably closer to 10" to 14" in group size based on what I am seeing even at 100 yards. There is a lot of shooter in these.

 

[acudaowner]

you could always shoot your first two warm up shots on a test target .

 

[UpSideDown]

Are you cleaning your rifle between sessions?

 

[JakeM]

Ok, cleaned and shot three more groups.

Going to mount my scope to my 6.5 and see if it’s me. I followed the fundamentals as closely as possible and felt good about every shot.

 

[UpSideDown]

You said you cleaned it. Are you cleaning before every string? If you're stripping the copper out of the barrel that might be your problem. Have you tried not cleaning it?

 

[1moaoff]

Ok, cleaned and shot three more groups. View attachment 7285096 Going to mount my scope to my 6.5 and see if it’s me. I followed the fundamentals as closely as possible and felt good about every shot.

If that's 100 yd groups I wouldnt expect better at 600

 

[JakeM]

You said you cleaned it. Are you cleaning before every string? If you're stripping the copper out of the barrel that might be your problem. Have you tried not cleaning it?

I don’t clean it after every shoot. I clean it about ever 150-200rd.

 

[JakeM]

If that's 100 yd groups I wouldnt expect better at 600

Reference post 12, that’s why I’am so confused.

 

[JakeM]

Is there a way to post a video on here without posting it on YouTube and then linking it here? I made a video of my fundamentals this morning so you all can point me in the right direction, and can’t get it off my phone.

 

[JakeM]

These are what I shot this morning.

 

[Dthomas3523]

What about with another rifle if you have one available to shoot?

 

[JakeM]

I’ll do that to but it’s my fundamentals under scrutiny with this gun so I’am trying to put it all out there so you all can help prescribe the problem. Any way to get a video on here off of my i6s ?

 

[JakeM]

Sorry everybody it was me not loading the bipod correctly. I got some more practice to do.

 

[Lowlight]

I can post your video and if you don't mind I can make it a learning experience by giving commentary on the video

If you let me combine them and then film an additional piece here i can talk about your fundamentals and what I am seeing

Basically a cause and effect lesson, but I don't want to use your video without permission @JakeM

 

[JakeM]

Yes please, me and lot of other people need this information. Thank you.

 

[JakeM]

Thanks for the advice. Six shots 100yd

You can use this to.