My Revolver's Throats vs. Boolit Size?

[emrah]

I'm casting for my S&W 642 snubbie. My cylinder chamber throats measure .3555 to .356.

Now, I've been loading and shooting store-bought boolits that were sized to .357 with no problems. I recently cast 600+ Lee 158gr. boolits. They dropped at .360, give or take.

My question is: what should I size these to? I figure the .357's are just fine, but aren't I pretty much limited to the .356 throat size? Sizing them bigger won't give me any more advantage, since they'll be "sized" to .356 before they even enter the forcing cone and barrel, correct?

Emrah

[Lefty SRH]

Sizing them bigger will only drive up the pressure. I'd size them to your proven .357. IMHO, you should have the throats reamed out to .358-.359

[Lefty SRH]

Do you have any leading problems?

[emrah]

No leading problems to speak of. Just slight leading at the forcing cone and beginning 1/4" of the barrel. Bumping up my charge (4.4 gr. Unique) didn't really alleviate it, but I'm really not concerned. It's just slight leading to begin with and never gets worse.

I was more trying to corroborate my own answer to my own question. It makes no sense to size them any bigger than .356. I suppose I'll stick to .357 just for sh#ts and giggles regardless, because I know they work.

Emrah

[HDS]

Leading there sounds like a bore constriction to me.

[MtGun44]

Pressure does not increase significantly for oversized boolits. They are soft lead alloy.
Size to throat or throat plus .001 or even .002 if it works best for you. Often measurements
are inaccurate, or the holes or boolits are out of round and the larger nominal size is
used to fully seal against some out of round conditions.

Bill

[1bluehorse]

The only possible issue would be if the groove dia. was 357 or 358. But if theres no leading that probably isn't a problem..from everything I've read the ideal scenario is the chamber throats slightly larger than goove dia with bullets (lead) sized to throat dia..or as MtGun44 says a little larger..