Question on size

[DirtyDusty]

I slugged my bbl. and measured the o.d. Of the slug with a caliper, and it was .429. I pulled my cylinder and measured the throat with calipers , and it measured .432. I am currently shooting some commercial 240gr. Swc with a beveled base .430 diameter, but I am getting a lot of leading from the forcing cone to about 2" forward. I realize the beveled base could be contributing to this, but what size bullet would be optimum for this setup!

[Moonie]

Calipers really aren't accurate enough to measure barrel/throat slugs. Best practice is to use a micrometer for barrel slugs and I've heard pin gauges are best for cylinder throats but using a micrometer on throat slugs will work too.

[Larry Gibson]

Odds are the bullets "size" isn't the cause of the leading. Some will say that is heresy but it's fact. The problem is one of the load or most likely the lube. I shoot lots of commercial cast in my .44s. They are most often hard cast with a hard wax lube and are sized at .429. 1st thing I do is TL them in LLA as per Lee's directions. With light to moderate loads iget minimal leading if any at all. For magnum level loads I wash off the wax lube with Coleman fuel and relube with NRA 50/50 or BAC lube for no leading.

Larry Gibson

[gwpercle]

Commerical cast are usually hard alloy , hard lube and good for magnum loads. Do as Larry suggests with Lee Liquid Alox lube and ,since you didn't state your load, if possible increase it a bit and see how it works. A lot of times hard alloy and bevel bases can cause leading when a softer alloy will slug up and seal properly.

[MtGun44]

Fit to throats for best accy. Use a good design, good lube and fit to groove diam or larger (like throat) to
stop leading. +1 on NRA 50-50 for full power loads. No real need for anything harder than air cooled
wheelweight alloy.

+1 on get a micrometer and slug the cyl, most people cannot measure ID accurately eough with a
caliper, aside from the +/-.001 accy limitations of a caliper to start with. eBay for a Brown and Sharp,
Starrett or Mitotoyo used mic, or Enco Tools online for a Fowler brand, usually available on sale for
well under $40.

Bill

[DirtyDusty]

Okay, got me a new to me Swiss made Brown and Sharpe mic. And slugged everything again. Bbl. slug is .4295 and throat is .4313. So would I need a .431 or .432 boolit? I am loading with dillon dies. Will they take a .432 boolit?

[MtGun44]

Fitting the throat is usually most accurate. The only issue is will a cartridge
loaded with an oversized boolit chamber in your chamber. Test with a dummy
round, then ask Mr. Target for the truth, only he knows. There are definite trends
and what "usually works", but in the end, only Mr. Target will tell.

Bill

[gray wolf]

I think you would be happy at .432

[runfiverun]

Dillon dies are really geared towards jaxketed rounds.
your starting boolit diameter may not be your final boolit diameter, I have to really watch this with my Dillon stuff.
I use the Dillon dies pretty much for jaxketed rounds anymore.
or for everything but the final seating and crimping.