Gas check fit

[ELFEGO BACA]

I recently purchased a new mold from the cast boolit website for my swedish Mauser and found that my Hornady gas checks do not fit unless I start them with a set of pliers!

Running them through my lyman sizer then expands the front of the bullet so it does not fit my chamber.

Casting bullets from the same melt in my old Lyman mold creates no issues.

The gas check slip on the mold with some free play but are a snug fit once the bullet is sized.

Anyone have this experience?

[GhostHawk]

I'm casting for a pair of Mosin's and a Yugo SKS all in .312. Bought a pair of Lee .312 molds, a 155 and a 185.
I am using a lee push through sizer, it was .311 but I am slowly reaming it out to .312 with emery cloth and a piece of dowel.

No, not having your experience at all.

"The gas check slip on the mold with some free play but are a snug fit once the bullet is sized."
This is exactly as it should be as far as I know. I have to wonder though if you had a mold before that was working, why change molds?

Sounds like they just made the gas check shank a thousandth too big, but it could be the particular alloy your casting.

And running them through the Lyman sizer should not expand them to where they won't chamber.

Might consider buying a lee push through sizer, they are cheap enough.

So I'd start by seeing if your particular alloy is casting large.
Then if the lyman sizer is causing problems consider switching to a Lee.

Good luck!


Gas checks mostly slip onto the shank with no effort at all, now and then one try's to go cockeyed which takes some finger pressure to straighten. Biggest thing I have to watch is that Gas Checks will fall off if I'm not careful as I push it through.

[Bohica793]

I am having somewhat of the same issue with Vulcan checks and a Lyman 311672. The checks do not "slip on" but must be seated with some force. I am currently seating them using my Lyman 45 by inverting the bullet and pushing the check onto the shank. I then flip the bullet and size (.311). Going to try some different checks soon to see if that is the issue.

[krallstar]

I am having an a problem maybe. My gator checks for .30cal i have to tap them on. They seem alittle tight on the shank. Sometimes i get a sliver of lead. Also using a lee push thru .314 The boolits are from a noe 314299 Dropping out at .316-.317 Was told .30cal checks for this

[GhostHawk]

Well after buying a used lee pot that was half full of something with a lot more tin content, all of a sudden some of my checks are requiring more force to put on. Alloy used DOES make a difference in bullet size it appears.

[TCFAN]

I am having the same problem with 3 NOE molds all 22 cal. using a new batch of Gator checks. The old batch that I just used up were tight but they would go on with finger pressure.This new batch of 3000 that I just received a few days ago are just a bit smaller and i have to use a gas check seater to get them on.
I have 4 old Lyman or Ideal 22 molds and the gator checks work fine on those boolits.The Lyman gas checks shanks are about 2 thousand smaller than the NOE molds............Terry

[JeffinNZ]

OK, there is a couple of things here.

First off, if the nose diameter of your bullet is increasing you are unintentionally 'bumping' it. The stop on the sizer is set too high and you are bottoming out the bullet then with the balance of the stroke squashing it and expanding the nose diameter. Let the stop down some so the top punch butts up on the sizing die without resistance.

The second point is if your check is firm on the bullet after sizing you don't actually have a problem. Just set the GC in the sizing die then place the bullet inside the GC, run the top punch onto the nose of the bullet and size.

Loose checks are a bit of a pain but once you figure out how best you can work to suit you it's not a drama.

[bruce drake]

Jeff describes what I did to a bunch of LEE 155gr 311 spitzers a decade ago. Used the wrong nose punch and the Lyman 45 was still set for the depth for my 200gr SWC 45 bullet...turned 200 spitzers into roundnoses...