Interesting results in cast alloy boolit

[Ohio Rusty]

I have been casting for my .380 using the 356242 90 grain Lyman boolit. The pic on the left is the boolit cast from WW's with tin added and I added a little bit of something else (maybe linotype) to harden the mix a bit more and those boolits come out between 93 and almost 95 grains. That is a problem as there is no cast boolit loading data for a 95 grain boolit.

I did another batch using 2 and 1/2 pounds of pure lead, 2 pounds of monotype and a few ounces of linotype added. Those boolits come out between 88 and almost 90 grains each. That is the weight I'm looking for to match the load data in the reloading manual for a 90 grain boolit. They will weigh just a tad more after they get lubed.

I melted the pure lead, then added the 2 pounds of monotype printer letters. When they melted there was a bunch of lead sludge floating on top. I stirred that into the mix but it just surfaced again so I skimmed off all that dross sludge. I'm thinking that may have been a bunch of antimony that melted out of the mix as my lead pot was only running between 600 and 650 degrees. These 90 grain boolits are hard as I can't scratch them with my fingernail. I just bought a can of 700X to use for these loads.


Ohio Rusty ><>

[earlmck]

Well Rusty, I'd say you didn't loose much antimony when skimming that second batch. As your scale proves, you have a whole bunch more tin/antimony in that second batch because the Sb and Sn are both lighter than the Pb and that is the reason batch 2 is so much lighter than batch 1.

[BattleRife]

You cannot separate the components of an alloy simply by melting them out. The whole concept of an alloy is that multiple metals are blended together at the atomic level so that they behave as a different material, distinct from its constituents. Whatever floated out was never part of the alloy in the first place, most probably an oxide that formed in storage.

[Silvercreek Farmer]

I wouldn't use up a bunch of rich alloy just to dial in a boolit weight. Maybe just back off a tenth or two from the max load.

[Mitch]

This is common for cat bullets not to be right on the weight the molds states it is.Use the alloy you need or want.if you are going to use max loads for these bullets and they are on the heavy side start on the low side and work up slowly.If you are going for mid range or light plinking loads you should not have any problems with the starting loads or a little above.

[Winger Ed.]

The listed weights are with the specific alloy used that is also in the books.
I think the recipe they use for the base line--- and it works real well for general use is Lyman #2.

I use less of the lighter weight 'goodies' than they do, and mine are always on the heavy side of what the mold is marked for.
An extreme case is my .45 cal. 405s come out to be more like 420 gr.

[oley55]

That is a problem as there is no cast boolit loading data for a 95 grain boolit.

Although not having zip to do with the alloy discussion, my Lyman 46th edition lists load data for 92gr cast. But I think taking a pic of the data and posting it here would be a rules violation. We can try something via PM is you are interested.

[kevin c]

When I ordered my first Accurate mold, I had to specify the alloy I was going to cast with and I picked Hardball, since that was what the commercial guys use. IIRC, the as cast weight with Hardball was pretty close (nominal weight 147 grains). I eventually settled on 95-3-2 and now the same molds cast about a grain and a half heavier. My MP 147 grain molds do the same. Regardless of the actual weight, provided I use the same alloy, I get the same weights from batch to batch.

I'd guess that your COWW based alloy had more lead in it than whatever alloy Lyman cut the mold for (Lyman #2 [90-5-5] perhaps?). Your monotype based alloy, if the batch was around five pounds, would have about the same tin as #2 but a lot more antimony, making it lighter.

I imagine just a few grains difference in bullet weight is problematic in a rifle round that's got significant chamber pressures and 2500-3000 fps velocities. In pistol, though, if working up from the published minimum charge for the cast bullet closest in weight to your own, adjusting COAL for internal case volume, I think there's a greater safety margin. After all, in my caliber, the Lyman reloading manual I have shows a range of nearly 50% from lowest to highest bullet weight, and in 380 a 33% change from lowest to highest. Being a bit under 6% more than your target weight means being cautious as you work up your load, but doesn't seem out of bounds for safety reasons. Be sensible though - easy for me to say, but it's your fingers and eyes.

[Land Owner]

I didn't find a published IMR 700X recipe for my 49-49-2 Pb-WW-Sn alloy that consistently drops a 104 gr. 380 ACP Ranch Dog TLF 358-100-RF boolit. I do find Lyman 4th Ed. published recipes in IMR 700X for 90 gr., 102 gr., and 120 gr. that are each similar, though thought provokingly a higher min. load for 102 gr. than 90 gr. - go figure.

We can argue the micro-chemical characteristics of the published alloys under heat and pressure and their interaction with the steel bore. The published alloy, being different, is only a piece of the "not published" issue.

I loaded my 104 gr. boolit between the published recipe min. and max. of the 102 gr., which has proven to be safe and reliable. I have no doubt that you can powder your 95 gr. boolit to the 102 gr. published characteristics and find a suitable safe and reliable powder charge.

Whether the tiny charge of 700X proves to be the most accurate only time will tell. Out of either of my Walther PPK, it is accurate.

[OS OK]

This chart shows typical size & weight differences in the various alloys used...

[dtknowles]

I didn't find a published IMR 700X recipe for my 49-49-2 Pb-WW-Sn alloy that consistently drops a 104 gr. 380 ACP Ranch Dog TLF 358-100-RF boolit. I do find Lyman 4th Ed. published recipes in IMR 700X for 90 gr., 102 gr., and 120 gr. that are each similar, though thought provokingly a higher min. load for 102 gr. than 90 gr. - go figure..

On minimum loads for low velocity cartridges you got to have enough oomph to make sure the bullet makes it out of the barrel.

Tim

[Land Owner]

The min. 380 ACP powder loads from the quoted text are:
boolit (powder) alloy
90 gr. (1.9 gr.) #2
102 gr. (2.1 gr.) 10 to 1
120 gr. (1.4 gr.) #2

This progression I don't understand. I am of the mind that it should take MORE minimum powder than the lower weight boolit to get the 120 gr. pill out of the barrel.

Does the alloy really make this big a difference? What I don't know about this hobby would fill an infinite library of shelves.

[rockrat]

Go to "reloadammo.com/380auto.htm". There is data for 95gr. boolits.

[dtknowles]

The min. 380 ACP powder loads from the quoted text are:
boolit (powder) alloy
90 gr. (1.9 gr.) #2
102 gr. (2.1 gr.) 10 to 1
120 gr. (1.4 gr.) #2

This progression I don't understand. I am of the mind that it should take MORE minimum powder than the lower weight boolit to get the 120 gr. pill out of the barrel.

Does the alloy really make this big a difference? What I don't know about this hobby would fill an infinite library of shelves.

It is not just you. We don't know that those loads were developed by the same person and why the set the limits as they did. If it is a published load then you can be sure that the bullet cleared the muzzle in the gun they were testing in. I doubt that every load developer tests to see how low they can go. In a 380 it could be they not only were concerned about the bullet clearing the muzzle but that there was enough oomph to cycle the action. Some loading manuals are not clear if their starting loads are powerful enough to cycle the action of semiautos. Others will make it clear that starting loads may not cycle the action and some people will tell you for older semiautos to start low and work up until the action cycles reliably.

Tim

[dtknowles]

The min. 380 ACP powder loads from the quoted text are:
boolit (powder) alloy
90 gr. (1.9 gr.) #2
102 gr. (2.1 gr.) 10 to 1
120 gr. (1.4 gr.) #2

This progression I don't understand. I am of the mind that it should take MORE minimum powder than the lower weight boolit to get the 120 gr. pill out of the barrel.

Does the alloy really make this big a difference? What I don't know about this hobby would fill an infinite library of shelves.

The anomaly in that sequence of loads is the one in the middle. Usually as bullet weight increases the powder charge decreases for a given powder. I doubt the alloy is what is making the difference. I suspect that those recommendations are from different source that use a different approach to load developement.

Tim

[fredj338]

You are worrying too much about 5gr. To be safe, use 100gr data, but unless you are at barn burner max loads, adding 5gr of bullet wt isnt changing much. Your bearing surface is still the same.