Reloading 357 mag for sass

[Burley Jack]

I have a lot of 357 brass and am looking for info on reloading info on using Trailboss and 125gn tcfp bullets…for Sass?

                                    Thanks Burley Jack…

[Edward R S Canby, SASS#59971]

Whatever load you are offered, check it against Hodgdon's online data: 3.5 grains starting load, 5.3 grains maximum load.

[Roscoe Regulator]

I use 158 grain to control max allowed velocity. I can also get that in a bullet profile that cycles reliably in my Lightning rifle. I use 357 brass a) because I have it and b) because it allows me to crimp in the intended groove. My pistols are 38 Long Colt or 38 Special, so it is not a matter of ammo common to all the guns. My bullet is the 158 TCBB from Penn Bullets, now available coated (or not). and with optional sizing (6-8 weeks).

[Rex M Rugers #6621]

When I shot 357s , loaded that same style and weight  bullet with 4 Grs. Trail Boss. Worked fine. My rifle was smoother operating with the 357 cases.

Rex 

[Roscoe Regulator]

1 hour ago, Rex M Rugers #6621 said:

When I shot 357s , loaded that same style bullet with 4 Grs. Trail Boss. Worked fine.

Rex 

I am using 3.5 gr TB with the 158 gr in 357 brass and liking it.

[Null N. Void]

3.2 to 3.4 grains of TB with a 125 TCFP.

[Imis Twohofon,SASS # 46646]

I load 125 gr RNFP in .357 cases because my 73 likes that length. I use different powder (3.1 gr of Cleanshot) so I cant help you there.

 

Imis

[Marshal Chance Morgun]

Personal opinion.  I'd switch to .38sp. Take it or leave it, up to you, but more shooters use .38sp. You are going to get their brass and they are going to get yours. L:ook closely before you reload.

[Bison Bud]

I'm pretty sure that with Trailboss you can load the powder right up to the base of the bullet without issues, but do not compress the powder.  However, you can load lighter and leave a bit of air space if you want.  As others have stated .357 Mag in not a real popular cowboy load.  However, my little Marlin carbine rifle cycles much better with the longer rounds.  Unfortunately, it also throws most of them forward of the firing line and I seldom get many spent cases back unless I try to get them after the match.  Frankly, if you've got them, use them, but if you need a longer round it's also possible to long crimp .38 Special cases to get a similar overall length.  Good luck and good shooting to all. 

[Three Foot Johnson]

6 hours ago, Bison Bud said:

I'm pretty sure that with Trailboss you can load the powder right up to the base of the bullet without issues, but do not compress the powder.  However, you can load lighter and leave a bit of air space if you want.  As others have stated .357 Mag in not a real popular cowboy load.  However, my little Marlin carbine rifle cycles much better with the longer rounds.  Unfortunately, it also throws most of them forward of the firing line and I seldom get many spent cases back unless I try to get them after the match.  Frankly, if you've got them, use them, but if you need a longer round it's also possible to long crimp .38 Special cases to get a similar overall length.  Good luck and good shooting to all. 

Kind of - the recommendation for Trail Boss is 70-100% load density. Figure out the useable volume from the base of the bullet, start at 70% of that, and work up if desired, but no more than 100% of useable capacity. If your chosen cartridge/caliber holds 5.7 grains to the base of a seated bullet, 5.7 x .7 = 3.99. Starting load is 4 grains, and max load is 5.7 grains.