Bumping Shoulders

[Phil]

I know that most bump shoulders between .001 and .002 for a bolt gun..

My question is where would you set the die to bump these cases?

Here are the measurements on my brass..

1pc @ 1.111
6pcs @ 1.112
6pcs @ 1.113
2pcs @ 1.114
2pcs @ 1.115

I realize this is only 17 pcs. of brass,but right now it is all that i have.

Phil.

 

[BoydAllen]

I would set my die according to the largest measurement. Your chamber is a fixed size, and bumping is to create clearance within it. If a case is not yet tight in that dimension, it does not need to be bumped. By setting your die to the longest, you will pick up the other cases as they get to that condition. Also, remember that a die setting is not a static thing, as you fire your brass more times, it will work harden, and have more spring back. You should fire all of the cases within a set in rotation, so that they harden up at the same rate, and the same die setting should work for all of them. If you don't do this a die setting that works for a hard case will over bump a softer one, and vice versa. If you happen to set your die for a softer case, the harder ones will not be bumped, giving you intermittent harder bolt closing that will open up your groups.

 

[gene pool]

Thank you Boyd for your explanation. I always learn something new every time I visit this forum.

Gene