Seating gas checks fully

M

m102404

Regular
Rating - 100%
6   0   0
I have been casting 8mm 175grn bullets and they're coming out really nicely and consistently. I have a bunch of 8mm copper gas checks from Dragon Lube and am using Lee Alox w/ a lee .323 push through die sizer that I opened up just a thou for the rifle I'm loading for.

The gas checks don't seat fully on their own before or as I run them up into the sizer (they're just barely grabbing the base of the bullet and can be easily picked/flicked off)...I can't just encourage them on by hand and have been using a little arbor press to seat the checks (shaves off a bit of lead) on then run them through the sizer (which works well). It's pretty laborious getting the checks to seat fully before sizing.

Any thoughts on what to try to save some work and salvage the gas checks I have? I am tempted to make a little stub with a .326" hole to put the bullet in nose first then press the check on...it'd be less fiddly than aligning things by hand/eye.
 
I am tempted to make a little stub with a .326" hole to put the bullet in nose first then press the check on...it'd be less fiddly than aligning things by hand/eye.
Click to expand...

That's pretty much what I do when the sizing die does not give enough resistance to seat the checks. I used a small soft face hammer (hard rubber)
 
The Lee push through sizing dies sometimes don't seat the check. I us a rubber hammer to tap the bullet fully into the check before I put them through a sizer if they are giving me issues. Looks like Yomomma has found the same solution. :)
 
A .38 super case works well enough....put bullet nose down into case, position check, press on with arbor press. Made quick work of things. Thanks guys!
 
It's more a matter of getting the check aligned square...moreso than the force to push it on. The round nose gets blunted just a little when I press it on...not consequential. The lead shaved by the cup seating is an annoyance but can be picked out, but that's as laborious as picking out lead shavings from a lubed groove :)

I loaded some as they came out of the sizer and some that I eyeballed post sizing and cleaned up...I'll see if there's any practical difference at the range next time.
 
I have cast, sized and gas checked thousands of 44 mag and 3030 Winchester bullets over the years and never had an issue using RCBS equipment.

I just checked my stock and see that I have also done 7mm BR with gas checked lead.

In your case, I would think there is an incompatibility between the size of the base and the gas check.
 
Last edited:
I remember an old Hornady advertisement that showed an enlarged drawing of their gas check. It showed a "crimp ring" at the top of the GC, suggesting that the GC was crimped on during the sizing operation in a Lyman 450 or similar machine.
I use a Lyman GC seater in the 450 when I size with Lee push thru dies. Never have a problem.
 
Annealing the checks will make them softer as well and easier to press on as the copper checks work harden when there formed.

A couple other tricks to help get the checks on is to use a small lag bolt with the rounded head to flair the check out some so it fits over the base easier. On occasions when I've had a few checks that were a snug fit. I used a soft mallet as well an drilled a hold in a soft wooden block to support the nose of the bullet and tapped the check on fully before running it through the Lee sizer.
 
You must log in or register to reply here.
Back
Top Bottom