Gas checks won't fit

[Buck-N-Rut]

I had a single cavity Lyman 358156 and the gas checks went on fine through lee 358 sizer. I traded that mold for a double cavity 358156 but the base isn't the same size. It looks like the gas checks should go on but the base is a tad too big. What the heck? Any solutions? Help would be appreciated.

[dromia]

You could try bevelling the base of the boolit's gas check shank, Al Nelson at NOE does a nifty little tool for this and/or you can flare the gas check by seating a suitably sized ball bearing on it and tapping with a hammer.

Is it the boolit over all that is bigger or just the gas check shank?

Is the mould closing completely, do the locating pins need resetting?

You could also play around with a cooler and/or softer alloy. Just because a mould is of the same design does not mean that it will perform the same way as another mould of the same design.

[44man]

Common problem. I have some boolits I need to tap the check on by tapping on my bench, others I need to press them on in a die I made. The worst is when they are too loose.

[Buck-N-Rut]

Just the gas check shank is bigger.

[Wayne Smith]

Anneal your gas checks and push a ball bearing into them. This opens them up enough to be forced on the larger shank.