? re: amount of shoulder bump

[jvencius]

When using a neck-sizing die set and a body die to bump the shoulders back of fired .338LM brass (that's how I ass-u-me shoulder-bumping is done...), how does one control the amount of shoulder bump? I've read that 0.002" is a good amount to set shoulders back but do you have to use Redding Competition shell holders to do so or is it a less-precise method, i.e. thread-in the die until it contacts the case mouth then turn it another 1/8 of a turn?

I've tried to figure out as much as I can about using neck-sizing dies but either this particular topic hasn't been covered (hard to believe that's true) or my search-fu is weak and I couldn't find it myself--sorry...

 

[James n TN]

This is how I do it. I remove the firing pin from the bolt so that the bolt will close with no force behind it. I then setup my bump die to just touch the shell holder and then back off 1/4 turn. I then size the case and stick it in the chamber and if the bolt is tight I then turn the die slightly down and resize the brass once more. I keep doing this until the bolt will close approximately free on the case for about 90% of the throw and then just a very slight downward resistance until bolt is fully closed.

 

[Rprecision]

When using a neck-sizing die set and a body die to bump the shoulders back of fired .338LM brass (that's how I ass-u-me shoulder-bumping is done...), how does one control the amount of shoulder bump? I've read that 0.002" is a good amount to set shoulders back but do you have to use Redding Competition shell holders to do so or is it a less-precise method, i.e. thread-in the die until it contacts the case mouth then turn it another 1/8 of a turn?

I've tried to figure out as much as I can about using neck-sizing dies but either this particular topic hasn't been covered (hard to believe that's true) or my search-fu is weak and I couldn't find it myself--sorry...

a hide member John runs this you tube channel. he has a episode that explains it better then I can. I think its this one, otherwise see his others

Mail Call Mondays #18 - Precision Rifle Reloading Overview - YouTube

 

[jvencius]

Thanks for the head's up--the video you posted wasn't the relevant one, but later on in the series I found the info I was looking for:

Mail Call Mondays #27 - Once Fired Brass Prep, RCBS Precision Mic, Hornady Headspace Gauge, Resizing - YouTube

 

[Rprecision]

A trick I didnt mention to maintain a more unifirorm distance from shellholder to die is; feeler gauges

pull the decapping pin, slip the gauge between the die and shellholder and adjust. Far cheaper them having mutiple shellholders

Lisle 68100 Deluxe Feeler Gauge: Tools : Walmart.com

 

[SWThomas]

Get a bump gage and it will be easy. Measure the fired case and then set the die up to where it sizes the brass/shoulder to .002 less that the previous measurement.

 

[former naval person]

JamesnTenn has it. Cuts expense of extra equipment to measure...which means increasing chances for measuring errors. Use the rifle. JMHO