Cast bullet sizing

320090T

I'm going to start casting bullets for my 44mag. I found a Lyman 450 but need to get a sizing die and top punch. I have been told to "slug" the barrel to determine the correct size of sizing die to buy. Advice on how to do this? Thanks!

charliemeyer007

Lots of ways to slug a barrel. Harder to do with a revolver, I don't pounding anything near the crown. I would just get a 0.431 die. If your mold is Lyman the first three numbers is the diameter, the next ones are the correct top punch. I like the 429421 Kieth 245 gr bullet and I use 50/50 Alox/Beeswax for the lube. I tend to cast them hard (straight wheel weight or Linotype metal) and drop them out of the mold into water.

bpost

Slugging your bore can help you decide but measuring the cylinder mouths can also help. For the 44 mag bullets I use a .429 sizer die and have a .430 for some guns that might display leading tendencies. Your 450 luber is actually the Lachmiller of the old days. My Lachmiller has sized untold tens of thousands of bullets over the past 40 years and is still going strong. As mentioned the Lyman 429421 is a awesome bullet, I have it in a four cavity. I have bought many LEE molds in six cavity and really like them too. As I get older the heavy iron molds seem to be getting even heavier...

320090T

I bought a box of 50 WW loads for the brass and just being able to shoot it. They pattern very well so I'm thinking of pulling one to measure the bullet diameter instead of ramming a chunk of lead into my barrel.

My mold is a .429. If I used a .431 sizing die, the bullet wouldn't size much seeing the difference in diameters. Am I missing something?

charliemeyer007

Generally bullets cast oversize due to the antimony in the alloy. Cast bullets are usually sized .001 or .002 larger than the bore. Proper choice of lube is important to help prevent leading. Back in the day there was a hard lube Rooster Red, wonderful for handling the bullets - no sticky fingers; but it didn't help with leading.

Hawk Carse

The usual recommendation for cast revolver bullets is to size to fit the chamber throats. Ideally, the throats will be the same as barrel groove diameter or very slightly larger. And easier to check.

Do bullets from your mold MEASURE .429" or is that just the catalog description?

A lubrisizer die larger than the as cast diameter will only lube the bullet, it will not make it larger. I don't know where the dividing line is, how much clearance you can have without squirting lead up onto the bands.

navc130

Slugging the bore means driving a lead slug or a round ball thru the bore and measuring the groove diameter. You can also pour a lead slug in the bore or use Cero-Safe to pour a slug. Obviously it takes some care to not harm the bore. Using inside measuring tools would accomplish the same thing.
Lightly lube the bore before driving a slug through it. Use a slug slightly oversize to minimize the force required to drive it through.

bpost

320090T wrote:

I bought a box of 50 WW loads for the brass and just being able to shoot it. They pattern very well so I'm thinking of pulling one to measure the bullet diameter instead of ramming a chunk of lead into my barrel.

My mold is a .429. If I used a .431 sizing die, the bullet wouldn't size much seeing the difference in diameters. Am I missing something?

It is nominally .429. Different alloys will drop different sized bullets. Checking the chamber throat diameters and going .001 bigger is the standard rule of thumb. If you get too big you may have chambering issues with thick walled cases. 44 Mag brass is available on the auction side for a reasonable price. If you use the proper lube, with a properly sized bullet leading will not be an issue up to rifle velocities of around 2,000 FPS.

charliemeyer007

Lots of ways to skin cats. One of best things about casting bullets is it opens many new doors to seek accuracy behind. Back in the day, some rifles were set up with muzzle or breach seaters for bullets. Some of these cast bullets were shoot without sizing and only lubed. Diameter, weight, style, lube, alloy can be new choices to play with. For rifles I like the Guy Loverin designs - short ogive, lots of grease groves. I seldom run gas checks but I might get one of the gas check makers. No aluminium ones in my good rifles - might be ok for use in a dark, pitted old war horse.

I have a 44-40 single mold .427, that will load and shoot fine without sizing (finger lubed) in my 29's. Haven't tried it in the Win 94AE yet. I have a .431 sizing die for my Lyman 310 set.

fatcat458

Simplest way to determine best boolit size is drop one into open cylinder. lf it falls thru the cyl throat the boolit is too small.. Needs to go thru throat with a slight resistance... NEWER Smith 44 cyls seem to be around .4295-.4300' .. Ruger BlackHawk cyl throats are at least .430'' from observing MY guns... l have no firsthand knowledge on RedHawk cyls

l personally size all my 44cal cast boolits @.431'' ...l also prefer softer ww lead alloys for casting

fatcat458

0n ANY revolver you slug the ''cylinder throats''... NOT the barrel.. lts almost impossible to get an accurate bore size on a Smith&Wesson barrel because it has five groove rifling

charliemeyer007

You need to use a proper V block to easily measure 5 grove barrels. https://www.practicalmachinist.com/vb/gunsmithing/measuring-5-groove-slugs-189215/