Seating Checks w/ Push-Thru

[LeadThrower]

Looking for some help before I ruin more of those rare 338 checks. (Pat, when's the 338 checkmaker going to happen:-P?)

I'm using a Lee push-through sizer (.338) to put a .338 Hornady check onto the Lee 338-220 boolit sized down to .334. The application is the Steyr-Mannlicher m95.

All too frequently, the check is deformed. Either seated at a horrible angle, or there's a "smear" of copper coming off the tail of the boolit.

Here's what I'm thinking:
Hone out another die to larger diameter to seat the check prior to boolit sizing, and/or use a softer alloy during check seating and then heat treat to harden if necessary.

Any suggestions?

[Calamity Jake]

Looking for some help before I ruin more of those rare 338 checks. (Pat, when's the 338 checkmaker going to happen:-P?)

I'm using a Lee push-through sizer (.338) to put a .338 Hornady check onto the Lee 338-220 boolit sized down to .334. The application is the Steyr-Mannlicher m95.

First off that check needs to be the same size as the boolit, .004 larger will reduce neck tension and cause some runout between case and boolit.

All too frequently, the check is deformed. Either seated at a horrible angle, or there's a "smear" of copper coming off the tail of the boolit.

Sounds like the boolit shank is a little oversize for the check, try flairing the check with a ball bearing or the head of a stove bolt so the check slips over the shank, then size to .334.
Also use some kind of lube on the boolit and check before sizing.

Here's what I'm thinking:
Hone out another die to larger diameter to seat the check prior to boolit sizing, and/or use a softer alloy during check seating and then heat treat to harden if necessary.

Any suggestions?

Have a good day.

[curator]

I'm a big fan of the Lee push-thru sizing dies but have had issues with correctly seating gas checks. Mine usually would end up getting crimped on the shank several thousandths off the bullet base. This resulted in checks coming off on the trip down range with attendant accuracy loss. Now I run the bullets through the die nose-first without checks, then apply the check and reverse the bullet, Sending the bullet through the die check first seats and crimps it perfectly. Where I have proper diameter dies for my Lyman or RCBS lubrisizers I still size nose first wth the Lee push-thru then seat and crimp check as I apply lube in the lubrisizer. This "double sizing" is worth the extra step in accuracy gains, and the major reduction in fliers.

[LeadThrower]

Thanks for the tips!

[Beekeeper]

Leadthrower,
Like Curator said I have been running the boolits through the Lee sizer check first on the 8x56R boolits with great results.
I had a lot of off center gas checks until I did and now seldom have any trouble.
I pan lube so after I get the checks on and lubing done I run them through the sizing die nose first and have excellent results.


Jim

[StarMetal]

Yup! Push through sizers are better then Lyman/RCBS sizers....unhuh. :kidding:

Joe

[Shiloh]

Run them through tail first.

Get an additional push rod from Lee, or make your own. Fit a small piece of tubing over it made from a piece of scrap or range brass. Secure it, a tight friction fit works, fill it with a bit of epoxi. Lightly oil or lube the nose of a boolit and set it into the epoxi filled tube. Run partially into the sizer die to straighten and align your boolit with the sizer die. Let cure, and voila' a custom fit seater die fot that boolit!! Put the boolit nose first in the new seater with the gascheck on the back and push through.

Shiloh

[GBertolet]

I'm uncomfortable with push through sizer dies using gas checks. My reasoning is that when you use a Lyman or RCBS sizer to seat gas checks, you are bottoming out the bullet and gas check against a square flat bottom. I feel this insures the gas check is more likely seated square and true. With push throughs who knows? I have a Star I use for plain base bullets, and as being a push through it works fine for these. I know some of our members have had decent success with the push throughs, so I am not condeming them, just pointing out a potential weakness in that system.

[Ben]

I don't get consistently squarely seated g/c's using the Lee Push thru system by itself. I like to seat the g/c with the New NOE gas seating die prior to sizing the bullet in the Lee Push thru. IT WORKS ! !

These gas checks were seated with the new NOE gas check seating tool. Bullets were sized in a Lee .310 push thru sizer and lubed in a separate operation in a .311 H & I die in my Lyman 45. This group was shot at 80 yards 30/06 Springfield, Model 700, 20.0 grs. 2400 with the SAECO # 315 HP , Wolf Primers.

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