44 Bisley Flattop pin gage question

[4bisley5]

New to the forum. I have a question for all those that have been through the journey of getting a revolver to shoot accurately with cast.

Just got my pin gages in. They were cheap enough @ 2.25 a piece so nothing to lose. I ordered ZZ minus because I think I read that somewhere. I'm not a machinist so I can't explain ZZ minus or plus stuff and to be honest didn't feel like researching.
This is what I know. .432 ZZ minus will not fit the throats but .431 ZZ minus fits snug
I checked all six throat and they felt consistent.
I did the egg sinker test through the barrel and came up with .429 at the muzzle and what I think is .4285 as close as I can tell on these micrometers. That doesn't seem aggressive but most all my handgun experience has been with jacketed bullets. I know they're probably more forgiving of such issues.

Seems to me I ended up with the lucky cylinder but what do I know. Can someone explain if that's acceptable for cast bullets?

[Hickory]

Sounds like you're good too go.
Size your bullets at .431 and you should have a good combination.

[DougGuy]

If they are even, THAT ALONE is the most important part. You can always size to fit the throats, and with a decent load under a soft alloy, the pressure of firing will size the boolit to the throats as they are fired. Like Hickory said, try sizing to .431" and see if all your loads will chamber.

For best results, you would want the throat .0005" larger than the boolit, so the boolit can be seated fully into the throat when chambered. If you have some that you have to push with your thumb, as long as they aren't too stiff to push home this is acceptable.

Depending on what alloy you cast, often a boolit will grow as it age hardens just sitting. Boolits that were snug in the throats when cast and then immediately sized and lubed may not go into the throats at all in a couple of months time. This is the nature of an alloy with antimony content, it's just what they do. For this reason I like to size throats a minimum of .0005" over boolit size, and finishing with the Acro lap often rounds them up to .0007" over the boolit diameter but this is enough to take care of a bit of growth, a boolit that didn't go through the die perfectly, a burr on the side of the driving band, slightly mismatched parting lines, etc... You need some degree of "wiggle room" in order to avoid a situation where some of the rounds will chamber and some are stubborn and won't.