POI Change? Hot Barrel

[j_volt]

I have a custom 300 PRC that might be having some issues. I’m relatively new to the custom rifle game, so I’m wondering if this is normal or not.

This rifle has a Bartlein CF M24 26” barrel, Defiance AnTi action, Manners EH1 stock, and a Trigger Tech Special trigger. All of the work was done by Alpha & Omega Rifle and Tool in Mound City, Missouri.

Here is the potential issue… this gun shoots perfect for the first 3-5 shots. Sub 0.5 moa. However, somewhere between that 4th and 6th shot, the POI drops fast to the tune of 2-3 moa. Once it drops, it remains relatively consistent at that low POI shift. For what it’s worth, I have been shooting between 60° and 85°. I have confirmed this hypothesis with multiple shooters and three different loads.

My question - is this normal? I get that this shouldn’t be a big issue for hunting, but my confidence in this rig is low. This is making practice very tough.

As a side note, I received this barrel with a “ding” out of the carbon. The barrel was sent back to Bartlein and they stripped the carbon and then wrapped it again. You can see that post here.

 

[Lawnboi]

Mirage off the barrel? Easy check would be less scope mag or a barrel mirage band

 

[j_volt]

Mirage off the barrel? Easy check would be less scope mag or a barrel mirage band

Good point - I thought that may be it, but I used a fan and have seen zero distortion. The low POI continues even if I give it a 5 minute break.

 

[MattB]

What did the company who built the rifle say about it?

 

[j_volt]

What did the company who built the rifle say about it?

I plan to call tomorrow. I was hoping to gather a bit of information prior to calling.

 

[Rifles And More]

Start with the easy stuff.

Is everything tight/tourqed? Check it all from action screws to scope mounts.
What scope - I missed that?
Change the scope out and try another.
I am guessing this is off a bench? Get down prone and try it out. No rest, just bags front and rear.
Clean the absolute piss out of the barrel.

Do one thing at a time and test.

If there is nothing there that resolves your issue, I'd be on the phone with the gunsmith quick.

 

[PsRpOiGrRiAtM]

Depending on how the barrel got the chip, that's the only variable in my mind that could've introduced stress to the barrel. Assuming, from a layman's point of view, that Bartlein's are stress-relieved from the factory, it shouldn't shift that much. Especially with carbon fiber reinforcing the structure. If this was a pencil-barreled mountain rifle, I'd say walking that much is the nature of the beast, but it's not. I'd be talking more with the 'smith and Bartlein.

 

[j_volt]

Start with the easy stuff.

Is everything tight/tourqed? Check it all from action screws to scope mounts.
What scope - I missed that?
Change the scope out and try another.
I am guessing this is off a bench? Get down prone and try it out. No rest, just bags front and rear.
Clean the absolute piss out of the barrel.

Do one thing at a time and test.

If there is nothing there that resolves your issue, I'd be on the phone with the gunsmith quick.

It’s a Zeiss Conquest V4 6-24x50. I have tried everything you mentioned besides actually changing out the scope.

 

[Formidilosus]

My question - is this normal? I get that this shouldn’t be a big issue for hunting, but my confidence in this rig is low. This is making practice very tough.

No it is not normal, and yes it is a big deal. It’s telling you something is wrong mechanically.

 

[Formidilosus]

Start with the easy stuff.

Is everything tight/tourqed? Check it all from action screws to scope mounts.
What scope - I missed that?
Change the scope out and try another.
I am guessing this is off a bench? Get down prone and try it out. No rest, just bags front and rear.
Clean the absolute piss out of the barrel.

Do one thing at a time and test.

If there is nothing there that resolves your issue, I'd be on the phone with the gunsmith quick.

If it is truly and consistently grouping for several shots, then dropping, none of the above is an answer.

 

[Rifles And More]

If it is truly and consistently grouping for several shots, then dropping, none of the above is an answer.

Probably a barrel issue?
I think it would walk with heat.

Just eliminating the accessible stuff first.

 

[Formidilosus]

Probably a barrel issue?
I think it would walk with heat.

Just eliminating the accessible stuff first.

Heat induced walking would show itself as a consistent and relatively gradual movement. If a barrel is shooting fine, and then suddenly drops, while it could be barrel stress from heat, more than likely it is a bedding/barrel fitment issue.

 

[Lawnboi]

Go give er 10 continuous shots at a spot at 100 yards and post up if it walks. That should get it nice and hot

 

[j_volt]

Go give er 10 continuous shots at a spot at 100 yards and post up if it walks. That should get it nice and hot

It won’t take 10 shots for the bottom to drop out of it. At first, I thought my scope was tracking bad. While getting used to the gun, I would shoot a few times at 100 then stretch to 400-600. The first shot or two would hit the metal target, then I would start missing. I would review the phoneskope footage, and end up making a 2.5 moa adjustment. After I determined the scope was tracking correctly, I finally realized that this pattern was happening and have since tested the theory with 9 strings of 5 to 8 shots over the past two days.

 

[Lawnboi]

It won’t take 10 shots for the bottom to drop out of it. At first, I thought my scope was tracking bad. While getting used to the gun, I would shoot a few times at 100 then stretch to 400-600. The first shot or two would hit the metal target, then I would start missing. I would review the phoneskope footage, and end up making a 2.5 moa adjustment. After I determined the scope was tracking correctly, I finally realized that this pattern was happening and have since tested the theory with 9 strings of 5 to 8 shots over the past two days.

If it is indeed walking I’d think it would get extreme after 10, which if documented well would really solidify your case should you go to the smith or barrel maker