Expander mandrel is removing size die shoulder bump?

Kyskeet

Private
Full Member
Minuteman
Feb 22, 2017
181
54
Loading 223 for trainer rifle. I am bumping Lapua brass .002 with a Redding "S" type FL sizing die and Redding compition shell holders. However after measuring the .002" bump I run an expander mandrel and remeasure 000" shoulder bump. I am. Lub bing inside the neck. Anybody else see this
 
Thanks for pointing this out. I'll have to check this more closely with my reloading. I've recently started using the expander mandrel reloading 6.5 Creed, and haven't noticed any change in shoulder bump. I have seen a drop in SDs by about 4-5 fps, finally getting me into the single digits. BUT, i'm relatively new to reloading precision ammo, and just trying to experiment and be a sponge!
 
Shoulder bump measurement before and after mandrel step is being measured with LE Wilson case gauge and a LE Wilson micrometer head space gauge.
 
Have you checked peice of brass in the chamber to see if it’s tight? Most of the time those guages arent cut exactly to the shoulder cut of your chamber or die. I’ve had some rifles only need a .001 by the guage to shut without resistance and some read .003 before it would shut without resistance. Angles from chamber, die, and guage could all be slightly different.
 
  • Like
Reactions: FatBoy
Loading 223 for trainer rifle. I am bumping Lapua brass .002 with a Redding "S" type FL sizing die and Redding compition shell holders. However after measuring the .002" bump I run an expander mandrel and remeasure 000" shoulder bump. I am. Lub bing inside the neck. Anybody else see this
Are you using the A .330 gauge?

Almost assuredly
 
By training rifle I will assume bolt action. I use an old stoney point datum line gauge BUT this is just for a final measurement.

I pull the firing pin assembly (and sometimes the ejector) and size a few cases down until the bolt handle has no resistance closing. After you do a couple you can feel the slightest drag at the very bottom of closing the bolt, 1/32 turn of the die and you have your HS set for a match rifle.

On a field rifle I set to barely drag on bolt closure, then measure the datum and reduce HS another .005".

Trob_205 hit the nail on the head. These tools are guided. The chamber is where it really matters.
 
  • Like
Reactions: steve123