New barrel and picky loads

[deaddog]

I recently put a 7mm-08 E.R. Shaw barrel on my savage. I've been working up loads with 140 gr Sierra gameking and a barnes 120 gr tsx. I've been able to get each bullet to give a 6 shot 1 inch group. The 140 gr Sierra really likes it with 38.5 grains of IMR 4064 and the Barnes with 41.5 grains of H4895. If I tweak either load by .1 grains of powder or the seating depth by .005 the groups open up to 2+ inches, usually with a bad flyer. I've never had this problem before and wondering if this is normal?

 

[Lefty7mmstw]

switch to the 140 sierra pro hunter... I've never had 1/2 the luck with the game king that I have with the pro hunter.... I still have around 800 of the pro hunter pills on my shelf even after trading all the 7mm's I had that liked them.... I like the pill enough to keep a stash of them...
another choice that usually shoots well is the 140 grain nosler tipped (either the bt or ab)...
If your combo is as flaky as you've stated you are likely seeing a screamer group occasionally and I doubt you will get that accuracy with multiple groups... Have you double checked everything on the rifle for tightness? is your scope known good?

 

[Shane Lindsey]

Are you shooting the Sierra and then immediately shooting the Barnes during the same shooting session without stripping out copper?

This may affect how they group as they are very different materials.

Just a thought.

 

[jsthntn247]

I've got a Criterion that is similar. If it go up or down a few tenths groups open up. I think barrel contour and possibly being button rifled has allot to do with it. I have to shoot it on the upper node before it flattens out somewhat so I can have a few tenths play. I would suggest you try finding the upper nodes and see if it shoots better. Try to get in the 2800-2900 fps range with the 140's and see if it tightens up.