32-20 Winchester in S&W 1905 4” - Mold Size

Kinda new here with cast boolits, but have been very successful with auto pistols (Glocks), auto carbine, and a Win 94 38-55. Now, I have an old revolver I’m resurrecting for a ranch pistol. First time casting for revolver.

The 1905 is a 3rd change - 1909-1915. Have checked all ‘gaps’ and the revolver is ‘tight’ as a new one. Recently fired it with HSM ammo that appears to be .314” diameter and it shot accurate with no leading. No pin gauges, so I pulled a new bullet and checked the cylinder throat vs barrel fit. The cylinder throats are slightly larger than the barrel. Bullet ‘hangs’ in cylinder throats but can be pushed all the way through with slight pressure. Bullet will not go into barrel, so the barrel is slightly tighter.

It appears that .314” shoots well and has no leading from exposed cast boolit. I will be powdercoating. I’m looking over molds and am wanting to use a 115gr RNFP.

My question is: What diameter mold should I buy? I’m looking at an Arsenal and they will size to whatever I say. My alloy used on other boolits drops a bit large at .003+/-; SN 0.97, SB 2.47, PB 96.6 = 11.2 BHN. I can use a Lee .314 sizer. PC should add about .0005”. I’m hoping to continue my current alloy as it works well on game. I know the more SB makes the boolit larger.

I’m wanting you experts opinions for a starting point. I’m thinking .313” mold size. Appreciate all input. I’ve learned a ton from you guys!

Seems .315 would be good. I too cast and load for 32wcf in 2 different s&w 1905s. I also shoot 32wcf in winchester lever guns, colt lightning, and colt saa. I've settled on the saeco 322 mold. Bullets drop around .314 and I size to .313 for all guns mentioned.

Thanks Kai.
My concern on size is that my melt seems to always drop large. I am trying to limit having to tweak on my melt to adjust to the mold. In your case, using .313 and dropping .314, I assume your SB is a low amount? If I were to use a .315, I’d bet it drops at .318ish. I also use the Lee molds on other cartridges.

Trying to understand.

Increasing the amount of antimony tends to increase the size due to less shrinkage. Many stock molds are designed to size in Lyman #2 alloy, and straight linotype will cast larger.

Your stated alloy shouldn't cast overly large unless the molds are designed for something else.

Your alloy sounds to be pretty much straight up classic wheelweight. Many of us add 2% tin to that for better fillout, and are effectively running at something close to 94/3/3.

You can easily size such an alloy down a couple thousandths, but you can't really make them fatter. I would choose to cast at .315"-.316", do your strange, newfangled "paint" thing, and finish with a .314" sizer.

Accurate Molds also has the ability to spec a mold for a wide range of alloys, and a pretty huge catalog of designs to choose from and tweak. . .or just start with a clean slate and say "I want diameter X, lube and crimp grooves located at Y, and meplat size Z". For what it sounds like you're trying to do, my instructions to Tom would probably look a little like this:

Start with the blueprint for 31-112M

Spec the diameter to drop at .315 with chosen alloy.
Eliminate the lube grooves - you won't need them with powdercoat.
(By the time those two things are done, you should gain a slight amount of weight)

Locate the crimp groove appropriately, if it's not already in a happy place.

A .32-20 with a 4" barrel? Sounds like a nifty thing.

My personal favorite 32-20 boolit is the RCBS 32-98 SWC, but there are plenty of others that are good. I can do no better than to echo Kai and recommend .313.
And congratulations on the nice old S&W.

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Originally Posted by Kai

Seems .315 would be good. I too cast and load for 32wcf in 2 different s&w 1905s. I also shoot 32wcf in winchester lever guns, colt lightning, and colt saa. I've settled on the saeco 322 mold. Bullets drop around .314 and I size to .313 for all guns mentioned.

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Kai, what alloy mix are you using, please?

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Originally Posted by Bigslug

Your alloy sounds to be pretty much straight up classic wheelweight. Many of us add 2% tin to that for better fillout, and are effectively running at something close to 94/3/3.

You can easily size such an alloy down a couple thousandths, but you can't really make them fatter. I would choose to cast at .315"-.316", do your strange, newfangled "paint" thing, and finish with a .314" sizer.

Accurate Molds also has the ability to spec a mold for a wide range of alloys, and a pretty huge catalog of designs to choose from and tweak. . .or just start with a clean slate and say "I want diameter X, lube and crimp grooves located at Y, and meplat size Z". For what it sounds like you're trying to do, my instructions to Tom would probably look a little like this:

Start with the blueprint for 31-112M

Spec the diameter to drop at .315 with chosen alloy.
Eliminate the lube grooves - you won't need them with powdercoat.
(By the time those two things are done, you should gain a slight amount of weight)

Locate the crimp groove appropriately, if it's not already in a happy place.

A .32-20 with a 4" barrel? Sounds like a nifty thing.

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Thanks Bigslug. I’ve been looking at that exact mold. Not being sure about COAL, the grooves may need to remain.

.314 mold all day long. My favorite .32-20 mold is #311-105T from Accurate. I told Tom I'd be using 1:20 tin:lead and that's exactly the diameter the mold drops. Works a treat in my 1922 Colt Army Special and S&W Hand Ejector, both .314 throats. Coincidentally it's become my favorite bullet in my Colt Officer's Model Target .32 too.

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Originally Posted by gnoahhh

.314 mold all day long. My favorite .32-20 mold is #311-105T from Accurate. I told Tom I'd be using 1:20 tin:lead and that's exactly the diameter the mold drops. Works a treat in my 1922 Colt Army Special and S&W Hand Ejector, both .314 throats. Coincidentally it's become my favorite bullet in my Colt Officer's Model Target .32 too.

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Thanks for the info. If I choose this mold, I’ll go with .314”. and a tolerance of .001 +/-. I’ve found the bullets I’ve already shot were .313 to .314 and shot great; POA and on target. If my melt goes large I can size down with no problems. Can’t see my mix going smaller.

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Originally Posted by Cast10

Kai, what alloy mix are you using, please?

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I cast my 32wcf bullets with ww and tin.

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Originally Posted by Kai

I cast my 32wcf bullets with ww and tin.

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@Kai
Do your bullets grow when dropped?

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Originally Posted by Cast10

@Kai
Do your bullets grow when dropped?

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For standard pressure .32-20 ABSOLUTELY ZERO advantage to drop-quenching. Stay with 8-10 Bhn.

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Originally Posted by Outpost75

For standard pressure .32-20 ABSOLUTELY ZERO advantage to drop-quenching. Stay with 8-10 Bhn.

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My post concerns allow properties and how it effects growth/shrinkage when bullet is dropped from mold. Will a .311 mold drop .311, or .314, or .310.

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Originally Posted by Cast10

My post concerns allow properties and how it effects growth/shrinkage when bullet is dropped from mold. Will a .311 mold drop .311, or .314, or .310.

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Now that depends on the mold.

@Kai

OK

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Originally Posted by Cast10

My post concerns allow properties and how it effects growth/shrinkage when bullet is dropped from mold. Will a .311 mold drop .311, or .314, or .310.

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This all depends on what alloy the maker of the mold was using to compute their cavity sizes. The Accurate Molds ordering process is pretty handy in that it groups a number of common mixes into categories of similar casting properties. If you correctly tell Tom what you are using, he can typically get you within .0005 to .001", which if you err on the plus side is easily within the realm of what you can deal with on a lube sizer.

Indeed, and it's that little bit of homework required on the part of cast bullet shooters that most newbies/neophytes/lazies disregard (present company excluded of course!), and then wail about poor accuracy and leading, etc. - and then the next words out of their mouths are "how do I powder coat?"

Having prior experience is priceless, and I’m old enough that I understand that. Reloading over 45 years and casting/powder coating over 4 years now. All is fine. I figure if someone with a like weapon would be able to pass along information on how to proceed, I’d listen. I get it when someone is vague, it’s OK. I consider any and all information is worthy. I was told a long time ago, “There are no stupid questions.”

I have never cast for a revolver, just Glock’s and Win 94. I’d much rather exhaust all avenues than blow up a weapon. As stated earlier, I’ve appreciated all the help. This has to be the most knowledgeable forum I’ve ever participated in.

On a separate note, I wish the SEARCH tools were better. X1000. I always look up all the info I can before asking a question.

Try pasting this in Google search box

site:gunloads.com 32-20 mold s&w 1905

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