tmatt

[tmatt]

I just bought a Rock Island Armory "baby Rock" in .380. I want to cast bullets for it but I understand the diameter for a .380 is .355. All of the molds I've found are .356. Can I use those in my .380? Also, the heaviest bullet I find for the .380 is 105 gr. Can I use a 105 gr bullet sized to .356?

[jcren]

I don't have that gun but my 3 380's all get fed .357+ (.356 polished out a bit). Favorite bullet is the Lee 95rf but have loaded the 105 swc and 120 tc and they all work when you get the oal right. Since you are starting out, grab some of the cfe pistol for it. Impressive velocity with a mellow recoil pulse.

[Outer Rondacker]

Welcome to the forum tmatt.

[frkelly74]

I would ask what you experience is with reloading. If you are kind of new at it please be sure to get one of the Lyman Cast bullet loading manuals and study it a little. Even if you are experienced at reloading jacket bullets there are still some fine points that will need a solution. The rule of thumb for bullet size being one of them, It is considered normal for cast bullets to be .001" to .002" over the bore size measured across the grooves. Reloading cast is not exactly like reloading jacket bullets. Study up and go slow..... And have fun....... and be safe.

[dondiego]

.......and ask a lot of questions here. These guys will have your answer. Welcome!

[country gent]

The 380 acp is a small case, the 105 grn bullet is also longer than the factory 80 grn bullet. This means case capacity is now less. Start low and work up to the performance you want or need. Pressure will build faster due to the small case capacity. Use published data and start at min load or even a little below it and work up. .356-.357 cast bullets work well but check the first few rounds ( plunk test) to insure they will chamber in your pistol. A tight chamber and .357-.358 bullets may be snug in the neck area of the chamber. Full length size rounds, expand and bell for the bullet, drop an appropriate powder charge and seat the bullet. I woud recommend seating and crimping in separate operations. Set the seating die just above the case mouth so it dosnt crimp then seat the bullets to depth, then raise the seater stem a little and lower die to proper crimp and crimp the rounds. This results in a better crimp and more consistant seating of the bullet. To make this easier a .030 shim can be made for under the lock ring to raise the die up when seating, this allows the die ring to remain set for the correct crimp and only the seating stem will need to be readjusted.