Lyman mold as-cast dimensions

[Inthebeech]

I bought two molds, 358212 and 358311, after buying the bullets from Matt's bullets, shooting and testing them - both of which are giving me excellent groups (Bullseye shooter) at fifty yards off a rest with no leading. So I bought these molds once I confirmed the bullets were accurate. I have not yet casted with the 165 gr RN but the 147 gr. RN is casting .361-.362 with 95-5. I need to size them .357 (which actually gives me .3575 which is perfect for my cylinder throats). I tried to cast at a higher temperature, just bordering frosting the bullets, to get them to drop a little smaller because when I both use the Saeco lubrisizer and Lee push through sizers, I get whiskers at the base (Lee) and above the top driving band (Saeco) because I'm deforming the bullets so much. I also have not yet loaded these to see if the whiskers will degrade accuracy. I should probably ask Matt how his bullets, when I order them sized to the same diameter, look so good? I think he's using the same mold. Any thoughts? I can size one mil larger and this very slightly reduces the whiskers and I may just do this to see if accuracy is still good. I don't need a hard alloy so if they might drop smaller I guess I can leave out the tin and go with pure lead? This is not preferred as I already premelted my 95-5 and poured about two hundred pounds of this alloy mix in to ready-to-use ingots. Suggestions?

Quick follow up from a call just now with Matt.
I can use a smaller punch in the Lee to eliminate the whisker. It will leave a circular impression but this could be minimized if I run a sacrificial, prelubed bullet through every few bullets to be more gentle in the sizing process.
If using the Saeco, size in two steps. same deal; incremental deformation rather than heavy all at once.

 

[Rick]

You could size them in two steps, Get a .360 or .359 sizer die for the first sizing then use your current die for the second sizing. Sizing ,005" in one step can be done but it's a lot.

 

[Petrol & Powder]

At 95/5 lead to tin you should be getting 10.1 BHn
95/5 is not quite 16:1 lead/tin but it is more than 20:1; That's a lot of tin for a 38 Special target load.
My typical handgun bullets run in the range of 9-11 BHn (usually right around 10.5) but with 38 Special you can certainly go a bit softer. 9 BHn would likely work just fine. A little more lead and a little less expensive tin might get you a slightly smaller "as cast" bullet. Plus it would save you that costly tin.
My suggestion would be to add a little pure lead to your alloy and see if that drops your bullet diamter.

 

[Inthebeech]

I'm getting BHN 9-10.

 

[Petrol & Powder]

I'm estimating the BHn using a lead calculator, so take those numbers for what they're worth.
In any event, a bit less tin (which you can get by adding a bit more lead) may help you with the "as cast" diameter.

97/3 will approxiamte 30:1 BHn levels and may get you where you need to be in terms of diameter without going below 9 BHn.

I have found that 10 - 11 BHn will work in a LOT of handgun applications, so that's what I settled on. However, you can go with a softer alloy in 38 Special without problems. Fit is king.

 

[KeithB]

I'm surprised that ANY Lyman mold casts large!

 

[Petrol & Powder]

I'm surprised that ANY Lyman mold casts large!

I was surprised too.

 

[JonB]

Quick follow up from a call just now with Matt.
I can use a smaller punch in the Lee to eliminate the whisker. It will leave a circular impression but this could be minimized if I run a sacrificial, prelubed bullet through every few bullets to be more gentle in the sizing process.
If using the Saeco, size in two steps. same deal; incremental deformation rather than heavy all at once.

Aren't you lubing your bullets? or are you PCing the bullets?

I'd suggest polishing your dies and using a lube on the bullets.

 

[JonB]

I tried to cast at a higher temperature, just bordering frosting the bullets, to get them to drop a little smaller

As I understand it, this is really only noticeable/measurable when there is Antimony in the mix.

 

[RBHarter]

At it own risk the moulds are designed around #2 or linotype ....... They likely cast significantly heavy also .

This is a good example of engraving displacement getting pushed all the way up or down.

 

[Winelover]

First Rule of Bullet Casting:

The softer the alloy, the smaller, the as cast diameter will be. Lead being the softest. Conversely, the harder the alloy, the larger, the as cast diameter will be.

Second Rule of Bullet Casting:

For any given bullet, the softer the alloy, the heavier it will weigh. Conversely, the harder the alloy, the lighter it will drop from the mold.

 

[RBHarter]

If that holds 100% for the mass produced 1 at a time by hand the mould must have been cut for a 38 Short/NP or 9×18 type pushing .363 in WW .

 

[Maven]

I bought two molds, 358212 and 358311, after buying the bullets from Matt's bullets, shooting and testing them - both of which are giving me excellent groups (Bullseye shooter) at fifty yards off a rest with no leading. So I bought these molds once I confirmed the bullets were accurate. I have not yet casted with the 165 gr RN but the 147 gr. RN is casting .361-.362 with 95-5. I need to size them .357 (which actually gives me .3575 which is perfect for my cylinder throats). I tried to cast at a higher temperature, just bordering frosting the bullets, to get them to drop a little smaller because when I both use the Saeco lubrisizer and Lee push through sizers, I get whiskers at the base (Lee) and above the top driving band (Saeco) because I'm deforming the bullets so much. I also have not yet loaded these to see if the whiskers will degrade accuracy. I should probably ask Matt how his bullets, when I order them sized to the same diameter, look so good? I think he's using the same mold. Any thoughts? I can size one mil larger and this very slightly reduces the whiskers and I may just do this to see if accuracy is still good. I don't need a hard alloy so if they might drop smaller I guess I can leave out the tin and go with pure lead? This is not preferred as I already premelted my 95-5 and poured about two hundred pounds of this alloy mix in to ready-to-use ingots. Suggestions?

Quick follow up from a call just now with Matt.
I can use a smaller punch in the Lee to eliminate the whisker. It will leave a circular impression but this could be minimized if I run a sacrificial, prelubed bullet through every few bullets to be more gentle in the sizing process.
If using the Saeco, size in two steps. same deal; incremental deformation rather than heavy all at once.

Keep in mind Lyman used their #2 alloy as a standard, RCBS something else, as did SAECO and Lee (Yes, they have standards!).

 

[Winelover]

I you purchase a over the counter factory mold and it happens to drop bullets at the diameter you want, with whatever alloy you're using, consider yourself lucky! Then go out and buy a lottery ticket.

Otherwise, just send your business over to the custom makers and get exactly the diameter you specify, with the alloy you specify.

For what RCBS wants for a 2 cavity iron ($139 MSRP), I'll give my business to the custom makers.

 

[Petrol & Powder]

I've been very pleased with the quality of RCBS molds but that 2 cavity limit is often a consideration.