Question about 312 sizing die

[chris in va]

I bought this to size and install gas checks on my Lee 155 7.62x39 mold. Should have got the 314, but oh well.

Apparently it would be a good idea for me to just leave the boolit unsized and shoot as-cast, somewhere around 313 in my CZ carbine. What is the best way to open up the die so the boolit goes untouched but still presses on the GC?

[Mustangpalmer1911]

What abour NOE gas check seating die?

http://castboolits.gunloads.com/showthread.php?t=102263

[HARRYMPOPE]

Many sizing dies have a tapered leade.You could just run the base in enough to crimp the check (with GC seater or the stop run up to seat the check)and pan lube or tumble lube in Lee Alox.I would just try a few sized .312 to see how they shoot first if you already have the sizer.

HMP

[NHlever]

I opened up one sizing die using a slotted dowel, and emery cloth in my drill press. I was worried that the extra clearance would make a mess with the boolit lube, but I use a pretty firm lube, and it hasn't. As others have stated though, I would try it as is since those dies con't always produce the diameter that is stamped on them.