Can anyone tell me the chamber cartridge comparator tap size and drill size or number. Thanks for the help. MTG

That question didn't make any sense to me.

If you mean the tap for the dummy cartridge primer hole for the Hornady OAL/bullet seating depth tool, it's an odd size you wont find in your corner hardware store.

5/16-36 is what you want. I forget the drill size, but thinking the correct size is a letter drill. I used the closest fractional bit & it works fine.

If that's not what you mean, I have no fuggin' idea.

Thank you 358WCF. The comparator was the predecessor of the Hornady OAL/seating tool. Have had this comparator for many many plus yrs. I believe before Hornady became the manufacturer. MTG

The original manufacturer was Tom Peterson's Stoney Point Products.

Tom designed and patented several products that previously needed to be custom made...like the Comparator and Bullet Seating Tool. Getting these available to the larger market of hand loaders was a big step forward for shooters. -Al

I’ve got a Stoney Point and the 5/16x36 tap is correct. L bit is the letter, but I used a 19/64 drill bit. Works just dandy.