Headspace... bumping the shoulder

[Russell3812]

Reading about the need to bump the shoulder of my fireformed brass .001" to .002" to achieve the correct amount of headspace in my rifle. I have a RCBS competition full length resizing die and a Lee Collet Neck sizing die for my .308. I have come to like my neck sizing die as it eliminates the need to lubricate cases and in my opinion shows improved accuracy over the full length die.

I have not bought a Headspace gauge so I do not know whether the neck sizing die bumps the shoulder at all. It appears to me that adjusting the die one way or another results in greater or lesser tension of the neck on the bullet.

When reading about "bumping the shoulder" does this only apply to full length sizing? Can it be done with a neck sizing die? Thank you for your input.

 

[NoFail]

Re: Headspace... bumping the shoulder

I should leave this to somebody who knows better than me, I just started loading for my rifle cartridge. But it seems to me that it would have to be the FL only because I think the whole body needs to be supported for the shoulder to be "bumped". My FL Forster Bench Rest sizing die is set per instruction provided and and it provides the bump this way.

 

[K2Ballistics]

Re: Headspace... bumping the shoulder

Your Lee die will not bump the shoulder... Also, see K2's rule number 7:

Reloading without mics, guages and chrono's is like flying without nav gear. You spend a good portion of the time not knowing where you are.

 

[recarga]

Re: Headspace... bumping the shoulder

K2 B. Said it ,
I started using a forster bushing neck sizing, this die is suppose to bump the shoulder back .002" but it didn't ,it was pushing it back .008" and I wouldn't found it if I didn't have a HEADSPACE gage.

Having the the tools to do the job right not only does it makes a good job,but it gives you peace of mind.

REGARDS.

 

[Russell3812]

Re: Headspace... bumping the shoulder

Thank you for answering my question. I've been reloading for a year now and seen considerable improvement in my groups. I've bought MANY gauges, tools etc and they just keep on coming! Just want to consult the experts before buying any unnecessary equipment. I think there's a lot of that out there.

 

[FLIGHT762]

Re: Headspace... bumping the shoulder

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: K2Ballistics</div><div class="ubbcode-body">
Reloading without mics, guages and chrono's is like flying without nav gear. You spend a good portion of the time not knowing where you are. </div></div>

^^^^^^^^^This is very true. ^^^^^^^^^^

In my many years of reloading and buying a number of shoulder bump/headspace checking gauges, I've found the Sinclair gauge to work very well. Buy the XL gauge body because it will also measure loaded ammo (the regular body will not). The body and an insert for a family of cartridges will run you about $25.00.

The Hornady bump gauge will work, but the inserts are made of aluminum. Sinclair inserts are steel and are cut to the shoulder.

http://www.youtube.com/watch?v=-n_l-bYxbg0

 

[MitchAlsup]

Re: Headspace... bumping the shoulder

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Russell3812</div><div class="ubbcode-body">When reading about "bumping the shoulder" does this only apply to full length sizing? Can it be done with a neck sizing die? </div></div>

Neither, you can bump the shoulder with a FL die, with a body die, and with some FL dies with bushings to size the neck. You cannot bump the shoulder with a NO only die.

In order to bump the shoulder, the entire case must be supported (all the way down to the base) and considerable force applied (58K PSI) to the brass. The case diameter is squeezed down at the same time the shoulder is pushed backwards. Both activities cause the neck to lengthen.

 

[K2Ballistics]

Re: Headspace... bumping the shoulder

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Russell3812</div><div class="ubbcode-body">Thank you for answering my question. I've been reloading for a year now and seen considerable improvement in my groups. I've bought MANY gauges, tools etc and they just keep on coming! Just want to consult the experts before buying any unnecessary equipment. I think there's a lot of that out there. </div></div>

Sound approach, especially if you are un-sponsored like me. LOL. Best of luck with your reloading.