Shoulder Bump affect accuracy???

C

C.L. Peterson

Active member
When starting to resize cases and your die is set up for another gun one may BUMP the SHOULDER more than desired. If your desired BUMP is 0.0005 to 0.0015 range but you bump it back 0.003--0.005 range by accident can one shoot these cases at record target without sacrificing accuracy???
Or should these only be designated foulers until fired and proper shoulder bump done.
I realize this is hard on the cases but I'm only questioning if this will affect accuracy????
Wondering if a study has been done or any experience with shoulder bumping and accuracy???

CLP
 
I dont think so. At least i havent noticed any difference in accuracy with a .001 bump or a .0025 bump. Actually today i shot a match with .002 bump and i won the match. I would try to keep your bump minimal though. Like you said, it is hard on cases. Lee
 
I suppose that there is a theoretical probability that you'll get random variations in ignition depending on where the cartridge lies in the chamber relative to the chamber's shoulder. It might even depend on just how close to ideal your firing pin spring tension is. Whether that is to a degree that degrades accuracy to an identifiable extent is the question that you can only answer by firing the rounds.

Of course, now you've raised that issue, you do have that monkey on your back.......
 
Try bumping it .005 like I accidently did for 2-1/2 days at this years Super Shoot. I guarantee that will affect accuracy. Discovered it by checking fit in the chamber...a bumped case would not extract!
 
You must log in or register to reply here.
Back
Top