how do you bottle neck a case for 357 sig?

[45calibre]

do you just need a die to bottleneck a 40 s&w case for 357 sig?

 

[XtremeVel]

A well lubed case thru the regular sizing die would do it, but not recommended... If you form the .357 case out of a .40 S&W, it will be .015-.020 too short...

Forming and trimming a 10mm cases isn't recommended either... It has a different internal configuration and also uses large pistol primers.

Best to buy once fired brass.

 

[Aszerigan]

A well lubed case thru the regular sizing die would do it, but not recommended... If you form the .357 case out of a .40 S&W, it will be .015-.020 too short...

Forming and trimming a 10mm cases isn't recommended either... It has a different internal configuration and also uses large pistol primers.

Best to buy once fired brass.

^^ THIS

Once fired brass is easy to find these days. And since 357 SIG relies highly on neck tension, that 0.15" can make a difference in bullet setback.

 

[ZbornacSVT]

I agree with everything above!

 

[45calibre]

how much is it to reload 357 sig per 50 rounds? i plan on reloading for 40 and 9mm so really theres no reason to not reload some 357 sig.

 

[XtremeVel]

how much is it to reload 357 sig per 50 rounds? i plan on reloading for 40 and 9mm so really theres no reason to not reload some 357 sig.

You are right... There is no reason not to reload .357... Especially if you want to see what the caliber is really capable of... Most of your store bought ammo has really backed off. I know many advertise only 1350 fps...

It will cost just a bit more than 9mm, but cheaper than 40 primarily because SOME 9mm (.355 dia) bullets can be used. The cost difference between 9mm will be due to (2) factors... More powder and probably a more expensive version of the .355 dia bullet.

If you want to run them as the round was intended, you will be using probably somewhere between 30-50% more powder than you would use in 9mm. This adds minimal addition cost if comparing the difference in cost between 9mm and .357 sig.

In addition to a slight increase in cost over 9mm due to the powder, you could also add a little cost in selection of the bullet. I own several 9mm's and if I want to shoot something below 1400 FPS, I'd just assume shoot them. When I load .357, I spend the extra and buy jacketed as opposed to cast or plated. That is where there will be a little additional cost if you compare to 9mm. If you aren't opposed to downloading the round a bit, Berry's makes a plated 124 gr flat point that works well with the .357's short neck. If you want to see what the caliber is capable of, switch to jacketed and Hornady 124 gr FP (HRN35567B) works great and you can get them in bulk by the 2900 pc case.

 

[Fullmag]

Montana Gold makes a couple of the heavy jacketed rounds just for the 357sig. Speer sells already loaded ammo. Just checked Starlines web site for new brass prices and they went up since I bought some, now $94.00 for 500.

The difference between a 9mm and a 357sig bullet, both .355 dia, is the jacket is thicker to deal with the increased velocity, which gives more penetration. The 125gr is the equal to 357mag in 125gr, not 147gr or 158gr. Some of the early S&W 357 mag revolvers using 125 grainers actually cracked the forcing cone because of the velocities.

 

[ZbornacSVT]

I personally use 115 Montana Gold JHP in both my 9mm and 357sig loads

 

[Cannondale]

I personally use 115 Montana Gold JHP in both my 9mm and 357sig loads

I also use the 115 Montana Gold JHP in both 9mm and 357 Sig with no problems. The load I use will chrono at 1550+ fps out of a 135mm barrel

 

[Fullmag]

Have been using the Rainers 124gr in 4" barrel 357sig. Do the 115gr shoot better? Have you also tried 125gr?

 

[Fullmag]

Also what type of powder. Thanks.

 

[ZbornacSVT]

Have been using the Rainers 124gr in 4" barrel 357sig. Do the 115gr shoot better? Have you also tried 125gr?

Also what type of powder. Thanks.

I use the 115 Montana Golds as I already had them for 9mm.
HS6 powder here.