.357 MBC hard cast UNIQUE powder

[thomis]

I'm loading some of the hard cast .357 mag bullets from Missouri Bullet Company, the "action" bullets with the hardest Brinell number. The only data I can find online is 6.0 max charge for a Speer LSWC.
I'd like to push these pretty hard, I'm shooting a Ruger KGP-141 4" bbl.
Please share your charge weights using Unique and this exact bullet, please.
Kind regards,
Thomis

If Unique is not the correct powder to push these as hard as they need to be pushed, to make the most of the harder lead, I'm open to hearing your opinions on that. I have other powders..

 

[rcmodel]

Is that the 140 grain bullet??
You didn't say what the weight was, and I'm too lazy to try to look it up, and too cautous to guess.

If it is a 140, 8.5 Unique should be considered a .357 max MAX load.
But work up to it slowly watching for hard extraction.

rc

 

[dogrunner]

I shoot the Keith 173 SWC & use his old recommended load of 7.5........chrono's about 1150 on average & I have no doubt it could be stiffened somewhat.

 

[thomis]

Ooops, it's the 158 grain hard cast...

It says "for magnum velocities" so maybe Unique isn't the best powder. I love Unique but I believe that if this hard of a lead bullet isn't driven to mag velocities, that's where you start to get the leading problem in the bbl. I could be wrong.

 

[ConcernedCitizen]

I'd recommend using 2400 instead of Unique. Unique will get you into the mid-range magnum loads, but 2400 will let you get to full magnum loads, with the added ability to download if desired.

 

[GLOOB]

I have two loads for that bullet. 6 grains of Unique, or 16.5gr of H110. They both shoot great.

So the bullet will surely handle faster speeds, but I was going by Alliant's data with Unique. As you have already found, it maxes at 6.

 

[James2]

Funny, I don't find much data for Unique and that bullet.

From Alliant: 158 gr Speer GDHP Unique 7.7 gr.

My own load for Cowboy loads, 158 gr LRN 4.5 Gr Unique.

I think leading is more a result of poor bullet fit than velocity.

Perhaps some H110 or IMR-4227 would give better results for the higher velocities?

 

[rcmodel]

I was going by Alliant's data with Unique. As you have already found, it maxes at 6.

Allants data is with a Speer 158 grain soft-swaged bullet.

Not a hard-cast bullet.

The 6.0 max is a velocity limit for the soft-swaged Speer bullet to prevent stripped rifling & severe leading.

Not a .357 Mag pressure limit with Unique & 158 grain real cast bullets.

It used to be 6.8 grains with 158 cast bullets before Speer & Alliant got together sharing load data.
That gives 1,295 FPS & 33,900 PSI in a 5.9" barrel.


rc

 

[Jesse Heywood]

From my list:

Lee #2: 6.2 gr., 1,188 fps; 6.8 gr., 1,295 fps, 33,900 psi
Alliant: 6.0 gr., 1,034 fps
Ken Waters: 7.5 gr., 1,274 fps

I haven't had good results with Unique over 6.0 gr.

My choice load is 15.5 gr. IMR 4227, Lee shows a max. of 15.8 gr. compressed, 1,253 fps, 35,800 cup. I also like 800-X for this bullet, but metering is not for those who don't have the patience of Job.

 

[zxcvbob]

Here's the load manual you want: http://www.castpics.net/LoadData/Freebies/RM/Alliant/Alliant03.pdf

8.0 grains of Herco is a great load with 158 grain cast bullets, so I would expect 7 grains of Unique to be really close. The above-linked manual says 6.8 grains of Unique is a max load, which is pretty close to the 7 that I guessed. Start at 6.0 or 6.2, and work up to 6.8

"Exact bullet" doesn't really matter with revolver cartridges. Weight and construction matters.

Do you have any AA#7 or 2400?

 

[thomis]

Naw. I have some AA#5, not 7.
I do have 2400 and already have a few hundred of the Missouri bullets loaded with that powder. I need to use up some of this Unique!