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How are these numbers for the 357 SIG loads?

Discussion in 'TOP GUNS *357 Sig* Club' started by sarge, Feb 23, 2010.

  1. sarge

    sarge Millennium Member

    Jan 26, 1999
    90.44.1W 35.48.4N
    I just loaded my first 20 357 SIG rounds this morning and took them to the range to chrono. I've been reloading about a dozen centerfire rifle and a dozen or so centerfire pistol rounds since the early 80's, but this is my first venture with the SIG round. I just never really wanted to tackle it with the short neck, but have recently decided to go for it.

    My load was 12.5 gr Accurate #9 under a 124 gr Montana Gold RN FMJ bullet and a Wolf small pistol primer. OAL was right at 1.140. I tried 13.0 gr but couldn't get it any lower than 1.155", which drug in my Glock 40 mags.

    Gun was a G22C with a G31 barrel, not ported. I have had the barrel for years and it probably doesn't have 50 rounds down it. I am ready to start shooting more SIG, so that's why I have decided to reload it.

    Here's what the chrono said for 10 shots...

    Hi - 1307
    Low - 1267
    AVG- 1284
    ES - 40
    SD - 11

    Inspecting the brass after it was shot showed no flattened primers or any signs of over pressure. The primers actually look better than they do on my 40 loads.

    I didn't have any factory loads to compare it to, brass was once fired Remington. Do those number look like I am on track?

    Second question. I have about 100 SIG brass, but 2 5 gallon buckets full of 40 SW brass. I have heard of people running 40SW through the SIG dies and making 357 SIG brass. I did that with 5 40's just to see what it did, but they measured a little shorter than the SIG brass. My concern is that since the factory round is already short on neck, will the even shorter neck on the resized 40 brass only cause more problems? Even if I only used them one time and left them laying or picked them up for the recycle bin I wouldn't have a problem with that.

    Or would I be better off ordering some once fired SIG brass?

    I see I'm gonna have a LOT of fun with this round!!

    Thanks for any thoughts.
  2. G33

    G33 Frisky! Millennium Member CLM

    May 29, 1999
    With G29
    Looks good.

    Yes, .40 is a hair short.
    In 1998 I used once fired .40 for my loads.
    Guys from the dept. would save it up for me.
    No real problems.
    Just watch the neck tension and check for bullet set back.

    Actually, the last needs to be done on factory ammo also.

    Now-a-days you can order .357 brass...Starline is great.
    Last edited: Feb 24, 2010

  3. sarge

    sarge Millennium Member

    Jan 26, 1999
    90.44.1W 35.48.4N
    Thanks for the note. I kinda figured they were OK but thought I'd check to make sure.
  4. hoffy


    Jun 12, 2007
    12.5 AA#5 is my pet load for all my 357s(three of them)
  5. countryrebel


    May 13, 2007
    My reloading books say do not use 40sw casings to make .357sig. A sigs case length of 0.856" is 0.0015" longer than the 40sw so sig cases should not be formed from 40sw brass,the result will be to short to provide correct .357sig head space on the case mouth. That is straight out of the nosler reloading manual.
  6. hoffy


    Jun 12, 2007
    best not to use 40 brass, i typed off my response in a hurry yesterday. I certainly wold keep the 40 brass (I keep anything but 9mm brass, have buckets of that and don't shoot it all that often). Also I have read in more than one manual not to form 357 from 10 mm brass due to the large primer, and i would guess that necks might need to be reamed. Heads up, I have been shooting this for years, and a few years ago I bought about a thousand speer nickel once fired cases. I think they had a lead free primer , or something, as the flash holes were small enough to break decapping pins . I just deprimed them with a lee universal decapping die and all was well . Also , these things will stretch, so trimming is another joy to go along with wiping or tumbling case lube off of them. I get several firings before they need trimmed and have a trim die. I really want a Dillon carbide die, but the $$$$$
  7. sarge

    sarge Millennium Member

    Jan 26, 1999
    90.44.1W 35.48.4N
    Things didn't go as well today as they did last week. After last weeks session, all 20 rounds that I loaded for testing loaded and shot just fine. I came back home and loaded 50 more rounds for another range session. I had several that wouldn't let the slide completely shut without a bump on the back, one that wouldn't let it go into battery at all, and 10 that only had light strikes. I'm assuming right now that I may have had too much crimp and the round slid just a little too far into the chamber and the striker just barely touched the primer leaving just a dimple. I'm going to back off the crimp just a little and run another 25 to 50 and see what happens. The rounds that did fire shot like a champ.

    Just an FYI too, this is all once fired Remington brass.
    Last edited: Mar 1, 2010