Which size gas check for .315 'boolitt?"

I have a .315 gas check mold on order. I plan to size to .313. Can I get away with using my supply of .308 Hornaday gas checks. Lyman makes .312 gas checks but these are currently out of stock at Midway. Can I use Hornaday .323 gas checks? TIA

NOE make a gas check expander tool. You can try that to open up those 30 cal checks.

I'm interpreting that answer as No, one cannot use .308 gaschecks on .315 bullets.

What mold? A 30 caliber gas check is for a .284" shank. Most, if not all .314"-.315" bullets I see have the .284" shank.

I use a NOE 316-213-RN (his version of the 311299, upsized). It drops are roughly.3165 - .317.

I size to 316. I have had no problems using standard 30 caliber gas checks from Hornady, or from Sage's.

Having said that, Sage makes a check specifically for 314 and up. I purchased some, but haven't yet used them.

The ordinary 30 caliber checks should work just fine. Check the mold drawings, but most "Fat 30" molds will have the .284 shank as mentioned above.

Aha! Match the gas check to the shank, not the bullet diameter! I feel foolish for not realizing the obvious, but I imagine I would feel even more foolish trying to mate .323 gas checks to what the mold maker's diagram indicates is a .283 shank. Thanks to all who responded.

Aha! Match the gas check to the shank, not the bullet diameter

Exactly right! Late to this thread, but I use the same .30cal. GC's on a .3165" CB as I do on "as cast" ones from .309" -> .314": No problems in seating them or with accuracy.

My 303 British mould , Lee C312-185-1R , which drops a .312 boolit uses a .30 cal gas check , same as the 30-30 and 30-06 mould , Lee C309-170-F ...the 30 cal checks on the .312 boolit works just fine.
Gary

FWIW I just miked a couple of Sage's 30 cal checks, o.d. is .320.

30 cal GC's should work fine, try one or two