Zero shift after running in

[adam]

I had my new rifle with a Krieger barrel and ran it in according to Krieger's info. What I noticed though is that after 20 or 30 rounds since running in the bullet was starting to hit the target 3 or 4 inches higher than when I initially zeroed it just after running in the barrel. Is this something that has happened to you guys? Does it mean that the barrel may still be settling down?
Thanks
Adam

[OldTurtle]

Your answer may lie in a couple of directions.... temperature of the chamber/barrel after the 20/30 rounds?.... My factory barrel will move up, with the group spreading a little, as the barrel heats.. but that's shooting some really rapid fire strings.

While the Kriegers are reported to be 'hand lapped', it may still have worked out the final 'rough' spots and allowed a little faster movement of the bullet, which, if my memory is correct, moves a group up a little. Most of my better barrels didn't get really worked in until about 100 rounds were fired..

[adam]

Cheers oldturtle. The 20 or 30 shots wre not fired in one session. I have only fired 2 or 3 shots in an outing during the last couple of months.

[stevecrea]

A shift of three or four inches is more than I would expect as the barrel settles in (I assume this is at 100 yards). I would agree with your assumptions, that as the friction is decreased due to proper break-in, the rounds would print higher.

You have probably already considered this, but I would check scope and scope mounts, bedding, freefloating, etc.

Is it still shooting similar-sized groups, with just the point of impact changed?

[OldTurtle]

One thing I failed to ask is regarding the stock on the rifle... Is it wood, composite, or custom fabrication...

My reason for asking is that if it is wood and part of the barrel channel/stock is not sealed properly, humidity change can cause a slight degree of warping and it may be placing a pressure point on the barrel or a shift in the bedding.

Composites are not as prone to humidity as they are to heat/cold and custom fabrications are usually developed to eliminate this probability..

[stevecrea]

I would also expect that if a shift were to occur due to further barrel running in, that the shift would be gradual, and not all at once. It sounds like your shift occurred rather quickly. Again, I would check all the likely culprits, including temperature changes, ammo sitting in the sun, snugness of screws, freefloating, bedding, scope and mounts, etc.