Neck truning short cases

[jambau]

I'm experiencing inconsistency with resistence while closing the bolt on my handloads. Some close more easily than others. I thought it was the neck length but that checked out. I began turning necks for the first time. This really helped accuracy but still I had different resistence upon closing the bolt. My dies are set to neck size only and the cases have never been fired from another gun. After turning necks I'm shooting 1.25 - 1.5" at 200" Yds. from an out-of-the-box Tikka T-3 and my best hand loads just kissing the lands. I know some will say "If it aint broke don't fix it" but I'd still like to eliminate it. I do not have this problem with factory ammo.

Thanks Folks,

 

[bohem]

Re: Neck truning short cases

You probably need to bump the shoulders back 0.001-0.002"

This can be done with a dedicated "shoulder bump" die or you can just FL resize the cases.

 

[jambau]

Re: Neck truning short cases

What causes the shoulder dimensions to grow on a fire formed case and what dies would you suggest for "bumping" back the shoulder? Can that operation be done by simply adjusting a full length size die or would that just full length size the case?

 

[bohem]

Re: Neck truning short cases

That would FL size the case. The last thing that the FL sizer does is close down on the shoulder and base region of the body on the case.

I believe that Redding makes a shoulder bump die that works off of a bushing. You can get different bushings for different amounts of shoulder bump.

This is a normal occurence with brass that has been fired several times and only neck sized. I have to do it every 4th or 5th time with my 30-06, I usually anneal the necks at that point as well.

 

[Brain]

Re: Neck truning short cases

Redding makes shellholders of different heights to adjust shoulder bump while keeping the die setup for your normal routine. With a neck die, they won't be of any use though.

You need to get a body die and adjust it in the press to bump the shoulders back the necessary amount. Measure case length to shoulder of a case that chambers with very slight resistance and then set the body die to size to that dimension...or a bit more if you'd rather no resistance when chambering.

 

[jambau]

Re: Neck truning short cases

Thanks guys,

I'll start making the changes and see how it goes.

Tikka

 

[427Cobra]

Re: Neck truning short cases

Don't buy the Redding shell holders, instead get a headspace gage, use it to set up your FL die, measure a fired case, then FL case, your looking for .0015 less than fired.