Barrel Change POI

[Skeptic123]

Put a new barrel on my 6BR and after 150 rounds it has what seems like a fairly big POI change compared to the old barrel. Both barrels were made at the same time with the same reamer. What kind of differences have you experienced when switching out for a new nearly identical barrel?

 

[Fuj]

Each barrel I have used over the years has it's own demons
even if machined twins.

 

[GLShooter]

Just like brothers and sisters. Shared DNA but totally different sexes.

Greg

 

[dnellans]

“Fairly big” isn’t specific enough for us to weigh in. Exactly how much of a shift? .5 inches at 100? 5 inches? 50 inches?

If t took you 150 rounds to notice it, it can’t be that big right?

 

[Skeptic123]

Lol...I was wondering what you all had experienced...that said I found 3, maybe 4 inches at 100...Gun did and still shoots sub .25 just with a different poi.

 

[JEFFPPC]

Barrels were not indexed?

 

[Skeptic123]

I don't know. They were both reamed by and fitted to a Pierce action by Pierce

 

[Spike A]

Maybe just curvature if the bore is different…

have you shot it at longer ranges? How does it do?

 

[dnellans]

Even if they’re indexed, the magnitude can be different. I have had as little as .3 moa to as much as 5 moa on barrels this year.

Even if they’re clocked the same, the magnitude of bore angle in the last 2 inches of the muzzle varies from barrel to barrel and is out of the gunsmith’s control. That said, I’ve found no noticable correlation between barrels that shoot and those that don’t in relation to that PoI shift (within reason above).

 

[RegionRat]

I don't know. They were both reamed by and fitted to a Pierce action by Pierce

It all sounds typical.

Why not give Pierce a note and see what they think too?

 

[Spike A]

Maybe just curvature if the bore is different…

have you shit it at longer ranges? How does it do?

Apologizes ladies and gents, didn’t this auto correct….

 

[ND shooter]

Apologizes ladies and gents, didn’t this auto correct….

Haha I knew what you meant. And I've used that word a million times.

 

[Ned Ludd]

Put a new barrel on my 6BR and after 150 rounds it has what seems like a fairly big POI change compared to the old barrel. Both barrels were made at the same time with the same reamer. What kind of differences have you experienced when switching out for a new nearly identical barrel?

Can you elaborate on the statement, "what seems like a fairly big POI change compared to the old barrel"? Are you referring to: 1) a POI shift between the two barrels when the scope knobs are on the exact same setting, or 2) a POI shift as the barrel warms up/fouls?

If it's the first of those possibilities...did you remove the rifle scope from the action when you installed the new barrel? Even if you simply removed the rings from the scope rail, it's quite possible the scope didn't go back into exactly the same position when you re-mounted it. Alternatively, could you have banged the scope against something during the process?

If it's the second possibility, reset your zeroes and move on with the new barrel.

 

[Lefty Trigger]

I had a 22 Fireball barrel made once and I think it got threaded crooked. Possible indexed from the outside diameter and not the bore? Could not get enough scope windage to make it shootable, scrapped it...lesson learned.

 

[jackieschmidt]

A lot of shooters chamber barrels by indicating the first three or four inches, and pay no attention to the muzzle runout. the late Gene Bukys chambered this way, and to no surprise, when he changed barrels, the next one might not even be on paper.

He sure won a lot. World Champion, Hall of Fame, and more.

So I wouldn’t worry about it.

 

[divingin]

Put a new barrel on my 6BR and after 150 rounds it has what seems like a fairly big POI change compared to the old barrel. Both barrels were made at the same time with the same reamer. What kind of differences have you experienced when switching out for a new nearly identical barrel?

I currently have 3 barrels for my bench rifle; 2 short range and 1 long range barrels. Switching between the old short and long range barrels yielded a vertical POI shift of something like 3 - 4 inches with just a bit of horizontal, which I lived with (what else are you going to do?) for the couple/3 years that the short range barrel lasted. Had a new short range barrel spun up and fitted; the POI change between that and the same long range barrel is about a 1/2" vertical and and inch horizontal. I haven't tried switching between the old and new short range barrels directly, but assume it will track what it was with the long range. The 2 short range barrels are the same profile, chambered and fitted by the same smith, and as far as I know were made using the same reamer.

 

[Rsadams]

Torque can effect barrel accuracy.... Too much is normally never good....

 

[David Christian]

POI differences are completely normal. No two barrels are the same. If you plan to shift back and forth between the barrels, just record the differences in your notebook and let'em rip.