Barrel swap/rezeroing problem?

[cdn shooter]

Looking for some feedback,

I just did a barrel swap from 300wsm to .223Rem and when going to rezero the rifle I had an 18 moa vertical change between the two. How can this be? I had the scope off the bases during the barrel change but I mean wow! Now I can't get zeroed with my 20 moa bases and have gone back to flats, which leaves me 19 moa of unused elevation and no way to get past 1000y without finding a 15 moa base or something. Frustrated WTF! I mean I just can't grasp how two bores can align 18 moa different in relation to the scope plane. Thoughts?

 

[stubblejumper]

What type of rifle?

 

[tiriaq]

It would appear that the axis of the action, and the axes of the barrels differ.

 

[paperslayer]

What make are the barrels?

 

[cdn shooter]

What make are the barrels?

One is a factory Savage and the other is a Kreiger.

 

[cdn shooter]

What type of rifle?

Savage model 12 Large shank.

 

[paperslayer]

I bet if you were to put one or the other barrel on a lathe and check the run-out, you will find one of the barrels is not straight. It does not mean they don't shoot, it just means they point in a different direction after you screw them on. Id put my money on the factory barrel since they are mass produced.

 

[coyote]

Barrel bores are never straight some are better than others , you would be lucky to find 2 barrels that you could switch back and forth on any action and keep the same POI.
Just removing a scope off the bases and replacing it will alter your POI so barrels are no different .

 

[Mystic Precision]

for scopes, approx 1 thou at the scope equal 1" at 100yds. To have barrels differ when spun on the receiver is a given.

Regardless of make or manf.

Reinstall the barrel and I bet your zero will change again. There is always a bit of tolerance in a thread and that will tighten up in a slightly different location. Just a schnick different at the receiver will mean a change at the target.

Jerry

 

[cdn shooter]

I expected some change but I didn't expect 18 moa change. Jerry I'll likely be contacting you for some bases.

for scopes, approx 1 thou at the scope equal 1" at 100yds. To have barrels differ when spun on the receiver is a given.

Regardless of make or manf.

Reinstall the barrel and I bet your zero will change again. There is always a bit of tolerance in a thread and that will tighten up in a slightly different location. Just a schnick different at the receiver will mean a change at the target.

Jerry