Cast loading question

[instrumentofwar]

New to this site. I have been shooting cast out of my 454, 45LC, and 45-70 for awhile. I have not had too many issues finding loads for them.

My question is regarding calibers that you normaly don't think about for cast. I was trying to find a load for 124/125 gr cast in 357SIG. I have loads for days in jacketed bullets, but I can't find any data in lead. Is a LRN projo a suitable subsitute (both same weights) for a FMJ, or would the type of bullet have that much influence on pressures?

Thanks!

[HeavyMetal]

I don't think it's the "Nose" shape itself that changes pressure curves but how far the boolit you want to use actually goes into the case. Bearing area ( bore contact area?) will also play a part in raising pressures.

So if you want to "sub" a 125 gr. RNL for a jacketed RNL the easiest thing to do is check ( boolit) OAL and seat accordingly. This may be difficult to do without a specific sample bullet.

Some manuals give bullet dimensions and with these you can figure a seating depth measurement and use that as a starting load / starting place!

Some simple observation and measuring should get you a starting depth for any reasonable weight you'll want to try in the 357 sig. Just follow safe practice's and start low on the powder charge and work up from there.

[Ghugly]

All else being equal. A cast boolit will give more velocity at less pressure than a jacketed bullet. No magic involved, it's just easier to push a lubed, lead boolit down a barrel.

[August]

Rounds with short necks are usually not good candidates for cast boolits. The 357 sig is (somewhat) notorious for its short neck and incipient boolit setback issues. I shoot some hard, plated boolits in mine with good success. If I were to try lead in mine, I'd certainly have a L>F>C>D on hand for the experiment.

[instrumentofwar]

Rounds with short necks are usually not good candidates for cast boolits. The 357 sig is (somewhat) notorious for its short neck and incipient boolit setback issues. I shoot some hard, plated boolits in mine with good success. If I were to try lead in mine, I'd certainly have a L>F>C>D on hand for the experiment.

What is L>F>C>D ?

[Dale53]

Lee Factory Crimp Die

If your cartridge has a bulge in the case or the bullet is slightly oversize the LFCD will size down the cartridge to minimize chambering problems.

Dale53

[Echo]

Charly Petty has an article in this months 'Handloader', but I don't think he got into cast boolits.

[instrumentofwar]

Got it, Lee FC die, ah-ha! Thanks, I have one in each of the tubular magazine/big bore guns, but I'm thinking it makes sense in the pistol stuff too. Do you know if Lee still has them standard in their pistol dies?

[Dale53]

The Lee FCD is standard in the four die sets. It can also be purchased by itself.

I have NO experience with the .357 Sig.

Dale53

[leftiye]

Originally Posted by August

Rounds with short necks are usually not good candidates for cast boolits. The 357 sig is (somewhat) notorious for its short neck and incipient boolit setback issues. I shoot some hard, plated boolits in mine with good success. If I were to try lead in mine, I'd certainly have a L>F>C>D on hand for the experiment.

I load 120 grain boolits in my 7.62X25. To avoid boolits being pushed back into the case I crimp lightly into a groove (lube or crimp groove) with the case mouth against the front wall of the groove. A lee fcd will crimp a boolit wherever you set it to crimp. Down side is that if you crimp into the bearing surfaces it will size them down some. If the brass is tough and thick enough it will size the whole boolit when the boolit exits the case.