Reloading 357 SIG

I’ve used AA9, BE86 and so far 800X has shot the best with 125 gr Montana Gold JHP bullets.

Alex G said:

Also, I realized I have some berrys 124 grain Flat Point (not thick plate) and 124 grain Target Hollow Point projectiles. Can they be used in 357 sig loads at regular velocities? Picture attached, with a v-crown on the right.

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Yes, you can use the regular plated bullets, but you have to keep the velocities down. This is statement from X-Treme bullets:

I have loaded plated bullets and even some ACME coated bullets. The problem with 357sig is, with a 124gr type bullet, you normally will see velocities starting in the +1200fps range. That is when you start losing accuracy with the thinly plated bullets. A better option for plated bullets will probably be 147gr bullets, since you have lower velocities.

The plated bullet I loaded most was the Berry's 124gr HBFPTP. This bullet works well in 9mm.

There are some good bullets out there to use, but with each new bullet, you have to make sure it will fit your magazine and gun. I normally do a few basic things before using a new bullet in 357sig:

• Find a COL that will fit your gun:
  • Ogive outside the case.
  • Pass the plunk test.
  • Fit your magazine
  • Cycles through your gun
• Test for setback by cycling it through your gun a few times.
• I normally would also try and push the bullet into the case after the setback test, just to make there is some good neck tension left.

RMR has some good bullets for 357sig: 147gr TCFPMW, 124gr TCFPMW and the 124gr MPR

Other bullets that worked well for me were: MG 125gr JHP, Sierra V-Crown 125gr (the V-Crown you show looks more like the 124gr bullet), Zero 125gr JHP, Nosler 124gr JHP.

Here is a picture of both 125gr (left) and 124gr V-Crown bullets:


You will probably need a debulger at some point in time, especially if you buy range brass. I use my 40s&w Lee FCD as a debulger for 357sig.

The COL for 357sig rounds are all over the place. I don't even try and target a specific. I let the bullet dictate what the COL should be. I have loaded COL's of 1.125", 1.135", 1.140" and even 1.150". They all worked, even the 1.150". The 1.150" COL was one of those longer nose JHP's.

I never load pulled bullets in 357sig. I have tried a few times, but the setback test just wasn't consistent enough for me. The pulled bullets weren't wasted, since I would just use them in 9mm.

Have fun and be safe.

kerreckt said:

I have found a cut a way style Sheridan gauge works great for setting up dies because you can see the shoulder set back. Removes all guess work. Best wishes!

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Alex G said:

Oh that’s cool! Can you send pictures to this thread?

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Here you go!

Alex G said:

Also, it doesn’t look like RMR is even producing these now
Any other ideas?

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They may produce them in runs. @longdayjake would be the one to ask.

Alex G said:

Also, it doesn’t look like RMR is even producing these now
Any other ideas?

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RMR must have pulled them until they catch up with all the orders. The 124gr MPR can still be backordered.
https://www.rmrbullets.com/shop/bul...hollow-point-multi-purpose-round-bullets-new/

It is difficult times to get/find components.

I shoot a bunch RMR 124 grain MPR ...Long Shot, 800x and AA#9 are my most used powders ... but I haven shot many others ...

The Hornady XTP 124 grain is my favorite ...

I shoot a few Hornady XTP 147 grain ....with 800 X ....I can safely get 1300 + fps in my Glock 31...

Ive use the RMR bullets but the 147 grain is flat based and takes an expander. I really like the everglades 147 grn that are tapered at the bottom and don't have to use an expander. I have two sizers, one a 40 cal carbide and then the steel 357 sig FL. I do not use lube. I use either WSF or BE-86 powder. Have not had any issues. I have started buying pulled primed brass... speer. This solves my primer issue and they shoot fine.

Speaking of loading lead bullets in 357 SIG. I have a Lee's 358-125 mold that I cast and sized the bullets down to .356". Hi-tek coated. Plans are to try them out in 9mm.

I sized and slightly bell mouthed 25 cases. Seated and roll crimped to OAL of 1.145". Dummy rounds.

Cycled them all through 2 guns. A compact and full size frames. All but 2 lost .002" on OAL. The 2 jammed into the feed ramp of the full size. They lost .013".

The flat nose looks to be too wide for reliable feeding. They may not work for 9mm either.

I have some MBCs 124 gr. Truncated nose that I may try next, if they don't see too long.

I have 2 sets of 357 SIG dies. Lee's and RCBS. The RCBS bullet seat can do a slight roll crimp. Not so much with Lee's.

Alex G said:

I’m assuming a slight roll crimp is a valid option with 357 SIG since it headspaces (or can headspace) on the shoulder?

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I wouldn’t roll crimp any bullet without cannelure. I prefer using a Lee Factory Crimp Die for .357 Sig

Alex G said:

I’m assuming a slight roll crimp is a valid option with 357 SIG since it headspaces (or can headspace) on the shoulder?

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That's what I was hoping, and the plunk test confirmed.

Lennyjoe said:

I wouldn’t roll crimp any bullet without cannelure. I prefer using a Lee Factory Crimp Die for .357 Sig

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Or a cast bullet that was meant to roll crimp.

kcofohio said:

Or a cast bullet that was meant to roll crimp.

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Touche

Lennyjoe said:

Touche

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You're point was valid. I doubt if there are many .355-.356" bullets out there that have a cannelure. And then it would probably be useless in 357SIG seating OAL.

Alex G said:

Got everything set up, with some 124 grain berrys FP bullets as dummy rounds to get me close for when the actual projectiles get here. I went to deprime/size the brass, and my decapping pin keeps pulling out of the shaft and getting stuck in the case! I’ve got a Redding die set. Any suggestions?

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Put a deprimed piece of brass in the die to help set the depth of the pin when you tighten it back down.

Alex G said:

Got everything set up, with some 124 grain berrys FP bullets as dummy rounds to get me close for when the actual projectiles get here. I went to deprime/size the brass, and my decapping pin keeps pulling out of the shaft and getting stuck in the case! I’ve got a Redding die set. Any suggestions?

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Oh the fun of reloading 357sig.

Some of the 357sig cases have smaller flash holes, which could be the reason why your decapping pin is getting stuck. I use a decapping pin with a smaller diameter, especially for these cases.

Alex G said:

Got everything set up, with some 124 grain berrys FP bullets as dummy rounds to get me close for when the actual projectiles get here. I went to deprime/size the brass, and my decapping pin keeps pulling out of the shaft and getting stuck in the case! I’ve got a Redding die set. Any suggestions?

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I'm fortunate on recapping pins. I use a Lee 40 S&W sizing die to decap and size the main body before running through the 357 SIG sizer. The 40s recapping pin is smaller diameter that most pins.

Speer brass seems to have the smallest flash holes of any other brass headstamp.

JayBeeKay said:

I'm giving serious thought to the .357 sig.
I'm curious whether anyone has tried a .357 dia lead SWC?

I don't want to hijack this thread - But it seems relevant to the OP anyhow

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My go-to bullet is a 130 grain SWC from NOE because it has a nice long straight bearing surface. I size to .358 and I’ve never owned a 9mm or 357 Sig that wouldn’t chamber them. My .356 sizing die might as well be a paperweight.

Slow powders are your friend when loading 357 Sig. Can’t get bullet setback if the case is already full.

Alex G said:

^This is literally EXACTLY what I ended up doing haha
Grabbed my Lee 40 die, checked the cartridge OD specs in the load manual to make sure they were the same, and went for it. Worked perfect!
I generally lube all my pistol cases with lanolin (9, 40, 357 mag and SIG, 38 spl, etc...) before sizing while they are still dirty, so having the carbide sizer ring in the 40 die is an added perk to reduce wear on my steel 357 SIG sizer die as well. Then they go in the wet tumbler and come out clean, shiny, sized, and ready to load! The more ya know...
Here’s the first batch done and drying:

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Great looking brass!

I used to use my 40 sizing die, but not anymore. My process is now as follow:

• Deprime using the Lee universal depriming die. Cases then go into a ready to clean container until I have enough to clean/process.
• Wet tumble full container of 357sig cases (already deprimed), and then dry.
• Debulge cases using 40 Lee FCD. I use a bit of Unique case lube.
• Resize cases using Lee 357sig resizer die, while cases are still lubed. I handle the neck/shoulder with my hands to make sure I get some lube on the neck/shoulder.
• Wash the cases without any stainless steel pins, then dry.
• Now they are ready to load.

I can probably debulge and resize dirty cases, and then tumble once, but I prefer to put clean cases through my dies.

You did not say where you got your cases from, so hopefully they won't need any debulging.

Looking forward to see you first test results.