7-300wsm

[65joe]

Any Ideas on why my 7-300WSM will shoot a 1 hole group at 200 yards and a 1/2" group at 400yds (both 3 shot groups) and a 5 shot group measuring under 1 1/4" at 500yds but only with new brass, can not get it to duplicate this accuracy with fired brass.
Norma brass 300WSM necked down to 7mm
necks turned for .313 chamber
Thanks Joe

 

[loaders_loft]

how does the velocity compare with new brass vs previously fired brass? maybe its higher or lower and you need to adjust the charge to match velocity?

Otherwise, maybe something is up with your dies. Are you using the same settings before and after, etc.

 

[65joe]

how does the velocity compare with new brass vs previously fired brass? maybe its higher or lower and you need to adjust the charge to match velocity?

That was what I will check next (speed) I also checked to see if I was getting a doughnut on the fired brass.
Thanks for the reply loaders loft

 

[jbroadnax]

Use new brass. Resize once fired brass and sell it to a friend you don't really like anymore. If a gun shoots like that who cares how it does once fired?

 

[loaders_loft]

jbroadnax, that's going to be a tough sell, considering his once fired brass is now incorrectly headstamped, formed to his chamber and "cursed"....

I think 65joe actually wants to diagnose and solve the problem

 

[65joe]

Loaders-loft, seems to be dead on with the speed analogy so far! Shot today at 100yds with some promising loads 4 tenths of a grain more powder seems to be the magic load in fired cases, 3 shot group measuring .194, now have to confirm at 500yds. Thanks for the help loaders-loft

 

[loaders_loft]

I had a feeling...