PC and sizing

[59sharps]

Not sure where this belongs so ill ask here. Mod move if need be plese.
when sizing PC do you size to the Jacketed size suggestion say.429 or the lead size suggestion of say .430. oh I'll size after coating is applied.
Thanks

[Wheelguns 1961]

Are these for revolvers, lever guns, semi auto?

[PJEagle]

They should be sized .001" to .002" over the diameter your barrel slugs. For example I load for .357's; one requires .359 and the others require .358.

[59sharps]

Are these for revolvers, lever guns, semi auto?
lever action rifle. 44 mag. marlin 94.
also j-bullets shoot very well at .429.
I cast for other levers and shoot .429 lubed for BP. no PC.
300240

[59sharps]

guess my question is why recommendation of .001 difference between lead and J-bullets. never thought about it before only casted for my BP guns and
sluged barrel for them first.
now im getting into PC for other guns. so its J-bullets VS lead Vs PC dia. in a given firearm. hence my ?? what's the reasoning behind different dia. for the same barrel.

[white eagle]

pc and size your boolits to the size the gun wants
can't put on a blanket and say it has to be .001 over because each gun is a law on to itself
what works in one may not be optimal for another only by shooting can you tell what yours likes

[charlie b]

I'd start by sizing same as lubed cast bullets. That is sizing after PC. My .308Win has .309 grooves. I size to .310.

[pmer]

guess my question is why recommendation of .001 difference between lead and J-bullets. never thought about it before only casted for my BP guns and
sluged barrel for them first.
now im getting into PC for other guns. so its J-bullets VS lead Vs PC dia. in a given firearm. hence my ?? what's the reasoning behind different dia. for the same barrel.

I'm not sure of the terminology but I'd say it's because of a difference in surface tension. Copper has a harder surface than lead and doesn't need as tight of a grip in the rifling of a barrel to get up in revolutions per minute.

[shortlegs]

Black powder bumps the boolit up to barrel size when it is fired, smokeless does not. Smokeless loads need to be a thousand or 2 over groove size to prevent gas blow by and boolit gas cutting. I size my cast boolits for handguns before I pc and shoot them without sizing after pc. For rifles I size before and after pc.

[GregLaROCHE]

You need to slug your barrel to know where to start. You can find a lot of posts on how to do it if you use the search engine.

[Dragonheart]

You need to slug your barrel to know where to start. You can find a lot of posts on how to do it if you use the search engine.

Absolutely correct! Any other information is worthless without a starting point.

But I will say this: would you buy and shoot jacketed bullets that are .002+" over what's needed to provide a gas seal? What do you think is gained by increasing pressure and forcing the barrel to swage a chunk metal to a smaller size? Because a PC bullet, is a jacketed bullet.

If anyone says "improved accuracy" I am going to reply, Prove it! Because in my testing, which was limited, using identical loads group size increased with oversized bullets.

[bangerjim]

I just cast PC & shoot whatever size my dies make, usually right on or .001 over barrel actual size. PC is very forgiving and will take care of any (minor) sizing problems


But.........................slug 1st before buying molds or dies. Just do not use PC as a "crutch" for poor craftsmanship in casting, sizing, and loading!

And I size after casting AND after PC to insure the perfect size every time.

PC works very well for many thousands of shooters!

[ChristopherO]

This is an excellent question and one I've been mulling over. In my 35 Whelen the bore slugs at .3585". For the powder coat boolits I can size them with either the .359 or the .360 die and the driving band will catch in the camber when the bolt is locked into place, scraping a spot of coating off in that one spot. I have to turn the boolits over in the Lyman 450 and size the front driving band with the .358 die, which mics out at .3585" on the boolit. These camber flawlessly. But, what if I just size the whole boolit to .3585" instead of the traditional .001 or .002" over bore diameter? If PC is akin to a jacketed bullet, whereas lube is only a grease smear that needs the projectile oversized, then maybe the PC can be sized to the bore diameter, too.?.

This calls for some testing on target to find out.

If anyone else has any real world insights any and all input is welcomed.

[Smoke4320]

I have always used the slug barrel first then .001 to .002 over the bore size.
Some shooting tells me which size each gun will like the best