I've been getting a few calls for the 357 family of barrels and I'm really torn on which one I like better. For ease of use, the 357 AMAG is easy to make brass, but you need the M1 mag set up. The 357 AMAX can work with a semi stock mag, but brass is a PIA. As I've shared with other builds, I've talked with Starline about custom brass runs and they gave me a couple of alternatives. Should hear more in "a few weeks"........ hope so
Well, we finally had a plan come together. Starline shipped me 500 "straight wall" 556 brass with no headstamp!
Looking at this brass, I can kiss the high attrition and multi step neck expanding process good bye and good riddance! Wooooo Hooooo
I haven't put a caliper on them yet, but whatever raw 556 starts out as is what we got. I've got a 2" chop saw set up and will start cutting when I get a length jig made.
From the test cuts I've made on the saw, trimming should be a piece of cake, followed by de-burr and squaring things up. Then we'll go after fire forming and get a bunch of light weight 9mm stuff cast up for that. As can be seen in the pic, the newly formed cases bulge the neck at the base of the expander and running light 9mm stuff makes the first go round much easier. Even expanding with a 357/38 makes formed brass loose for the bullet. Once they are fired, they are fine. I can't wait......
The brass is not annealed at all so we'll see if that is going to make a difference or not.
Was that a custom brass run or can us grunts also order the stuff. I was reading all the problems you had trying to get the original brass to work and this looks like a perfect way to go if the brass is available to us.
Hey All, Got chop saw, work stop, calipers, and brass set up today. Raw brass measures .351/.352 ID and .009" wall.
After cutting the brass is getting thicker but still measures close to .350 at the very mouth, but gets smaller the deeper in you go. Walls measure .0105"
Chopped some cases, deburred, reamed inside primer hole flash, ran through expander die, and then the sizer die. The expander puts a bulge at the bottom of the expansion and needs to be smoothed out with the size die. Once they were re-sized, I used the custom case length trimmer to square up the mouths.
Next step is to load up some fire form rounds and do some testing. We will do some measuring, but if we keep light bullets, we shouldn't get into any neck reaming, I hope.
Hey All, Made a way too short trip home and worked on a couple barrels. Getting more interest in the 357's so we are working on a custom reamer for solid case mouth location and a bit more throat for the 357 Maximum. We can't go too much more on the 357 Mag and still use the M1 carbine magazines.
I did make up a new set of Go Gauges for the two 357's. The main issue is time..... I just don't have any. I've thought about relocating some equipment, but the cards just seem to be stacked against me lately....
We'll see how the custom reamer goes and keep you posted.
I haven't throated anything yet, but want to get some ARMAX testing done with the new mag set ups this weekend. Hoping I can throat a barrel before then. Working out the brass cutting process and effect on fire forming before I cut a whole bunch. Would hate to come up short! Did get some ARMax loaded up and will see how that brass comes out after fire forming.
New brass fire forming still is a multi step process. We are going to try a new step and see if we can smooth this out. 357ARMags feed ok out of the new mags so we're going to build a few more. ARMax is using a slightly modified PMag. Still need to throat a couple of these brls....
Loaded up some newly cut ARMag basic brass tonight for fire forming tomorrow with 125gr XTP's and a load of 2400. Been swamped trying to get the new shop set up and orders out so new testing has been slow (but faster than it was!) If this batch fireforms ok and comes out to a good length I'll cut a batch of them and then swap over to ARMax brass and do a batch of that. Need to throat a barrel and working on a set of tools so I don't go too deep.
adjusted the 1st cut on the mag brass just a bit longer because they shrink a bit during expanding and re-sizing. Going to cut up a pile and then switch to Max brass. Cases still need fire forming to run smooth in the AR set ups. Just finished two barrels with throated chambers so when I do some reloading tomorrow we will see how that effects things. It would be nice to get a big ol fat 358 cast bullet in there.
Cut a few hundred Mag brass and switched to Max... much easier because of the thinner wall thickness... The shorter mag brass is just thick enough to bulge when you load a bullet and won't chamber as nice during the first loading. I expand the necks then run through the sizer again to stretch brass out for final trimming.