A Couple of 357 Mag questions

[shaman]

This is my first year of casting for centerfire rifle and pistol. A while back, I decided to turn all my .35 cals into cast lead shooters. So far, I've been very happy and very happy with the advice y'all have given me. Along the way, I've gotten into Powder Coat, and have good luck with it in my 35 Whelen as well as my 357 Mag Marlin 1894.

I just have a couple of questions for y'all in regards to the 357 Mag. These are somewhat unrelated, but they're coming out of the same rifle.

Question 1:

I have developed a nice hot 357 Mag load using a Powder Coated 358 grain GC'd Lee bullet and 16 grains of H110. It clocks at over 1800 fps. I can hit a pie plate offhand at 50 yards. However, I had to change out the rear sight and put a Williams peep sight on the receiver to get there. While I was sorting the last batch of brass, I found a rather serious split in one of the cases. This was the 5th or 6th loading for this brass. It went almost all the way to the head. Should I worry about this or just chuck that lot of brass? In 15 years of loading, I have not seen a pistol case split like this.

Question 2:

I had some lead 125 grain Lee Bullets out this weekend-- just plinking loads done up with 5 grains of Tightgroup. These are also the practice loads I use for my CC Ruger LCR. They clock just a hair better than a 38 SPL +P. I was using them to check out the new Williams peep sight. After shooting a 4 inch group at 50 yards, my son and I took turns plinking water bottles. One round found a rock in the grass, ricocheted , and embedded in a fencepost. My son dug it out. It had a bit of a dent from the rock, but otherwise it had no deformation. This is the same alloy mix I'm using in my 35 Whelen. Should I be worried that this alloy is too hard for deer hunting? The alloy is 50% WW and 50% PB.

[petroid]

Just a WAG, but I would think that the 158gr bullet with its larger meplat and being pushed harder would have a better tendency to expand than your lightly loaded 125gr with a smaller meplat and after skipping off a rock and burning off some velocity. The heavier bullet will have its own mass to help it penetrate and expand.

Line up several water jugs and/or scrap pieces of lumber and do your own test.

[chboats]

shaman- if it was only one case that split I wouldn't worry about it. If you have several, that's another story. Hot load loads will cause them to split sooner. Some of my brass I have been using for 30 years. Out 200-300 rounds I will have one split case. Most of the time I load about 38+p in 357 brass, so they are not very hot.

Carl

[Wayne Smith]

Loading hot loads, as mentioned, does limit the useful age of the brass. It will be helpful if you know the number of reloads. When you see one split it means the brass is brittle. Annealing can put a few more loads in the brass but you should be thinking about getting some more at that point.

[P Flados]

I shoot the 357 max (both a Contender & Dan Wesson). Since this cartridge was based on guns that could also handle the 44 mag, the 357 max was rated for higher pressures than the 357 mag. I "did the math" once and found that the stress on the gun from a 44 mag is real close to the stress on the gun when a 357 max is loaded to 55k. Note that the hottest of the common cartridges (454 Casull and a bunch of bolt gun cartridges) are held to 65 k. The 65k is probably where the base of the cartridge is close to yield. Note that this discussion is a little fuzzy since the ammo industry uses funky standards where the measurements are not really pressure in honest pounds per square inch (a pet peeve for this engineer).




case od
area
press
force



(in)
(sq in)
(psi)
lbs)


44 mag
0.457
0.164
40000
6561


357 max
0.379
0.113
58000*
6543


30-30
0.414
0.135
48600*
6542



* These are over the ratings and are being shown based on equivalent force applied to gun.

Since your lever gun can handle 44 mags, it certainly qualifies as stout for a 357 mag.

Your 16 gr of H110 under a 158 does not sound anywhere near "too hot" given the above discussion, it is probably well less than 40k.

High pressure in tapered ammo and in bottle neck ammo is different than for what you have, a straight wall case.

For your gun, I will argue that the brass is not "damaged" by high pressure until you start to getting close to loads that result in loose primer pockets.

Each firing/reloading does put the case through a circumferential stretch then compress cycle.

This is what leads to work hardening and then splitting.

If you take brass and measure it before and after sizing, you can quantify what is going on. The amount of increased of stretch from "hot loads" in you gun will be very small when compared to the stretch from moderate loads.

I have loaded 38 & 357 cases to the point of having lengthwise splits in my handguns. I do not like it when I find a split, but I usually do not even notice the split until I am going through the cases when I get home. This is much less worry than the neck separation concerns on stuff like my 30 Herrets.

As far as boolit performance, the Lee 158 GC at 1800 fps with 50-50 sounds pretty good. However WW is not the most precise raw material to work with and you did not mention any Sn or pewter.

I have some 50-50 that is still more brittle than I like. I can clamp the lower half of a boolit in a vice, hit it sideways with a hammer & some will shear off instead of bending over.

Some expansion testing with your metal would be nice. If needed, blending down for a little bit softer for "actual hunting boolits" might also be worth a try. With PC and the slow powder you are using, more than a little softer would probably still work fine.

I have just recently started working on stuff like 2 parts Pb to one part COWW with a little Cu in the pewter.

[shaman]

Thanks all! That was just what I was looking for.

[williamwaco]

Cases split all the time.

This is not advice but just a report of what I do.

I load them til they split then toss only the ones that split.

http://reloadingtips.com/pages/case_failures.htm

That said, I do not load as hot as your 16 grains of H110 load.

I rarely exceed 12 to 1300 fps.

[shaman]

Normally I don't either, but I'm toying with the idea of using 357 Mag cast loads for deer-- not with the 125 grainers. I'll use the 158 gr GC for that. So far, from what I've seen, the load looks reasonable for a close-in shot from a treestand and the rifle is doing its part now that I've put a new sight on it.

[Blackwater]

If you're shooting a carbine, many have rather generous chambers, and that can add to the number of cases you get that will split. The more ctg. brass moves, as in a generously proportioned chamber, the more the liklihood a case will split. As stated above, this is just a sign that that particular round of brass had probably work hardened, and annealing can extend case life, but generously proportioned chambers will always work the brass harder, due to allowing the brass to move further upon firing, and will inevitably cause more split cases, but since brass for a .357 is fairly cheap, it shouldn't be a big problem. Just toss 'em when they split, and anneal when you start getting very many splits. Never chuck a group of unsplit brass. NEVER! You never know when it might be handy to have it on hand for emergencies, if nothing else.

[dudel]

Is your sizing die clean? If you look at a sized case, and see scratches running the length of the case, you could have grit on the carbide or steel die. That grit is going to scratch the brass, weakening it along the length. A hotter than normal load isn't going to help the situation. You'd be surprised how dirty the dies can become. I clean them with a proper size bore brush wrapped with a wet patch. I use whatever bore cleaner is out on the table. Clean brass will keep the dies from getting as dirty; but they still need occasional cleaning.

When my 357 brass split they were usually splits at the case mouth. That showed work hardening and it was time to anneal the case mouths (or toss the brass).