Alliant PowerPro 300-MP, 180 XTP in .357

[RealGun]

Loads for PowerPro 300-MP are not easy to find, but one quickly learns that this powder is not for the smaller guns in most people's hands.

Alliant only lists a max charge for 170 gr jacketed. Hornady, thankfully, lists a number of loads for their 180 gr XTP, pretty much the big boy for .357 Magnum.

I tried the 17.0 gr load and got a painful bone bruise on the second or third shot and stopped. That was right through a padded glove. I came back today with 16.0 gr and a new Hogue "Tamer" grip, and all went well. The load felt like a magnum but was not unreasonable and punishing. I could have continued well past the dozen rounds I had prepared. It will become my go to round for shooting anything other than paper.

I can go on now and work on my lead loads. I have a bunch of 158 gr LSWC bullets.

The gun was a Ruger GP100 5".

 

[Kurastduuks]

if you have a chrono id love to see the numbers

 

[gamestalker]

Absolutely RealGun, if you have a chrony please provide some results. I've been wanting to give that powder a try. I'm a big fan of H110 / 296 and wouldn't mind finding a powder that might take things up a notch.

GS

 

[Schwing]

I know this isn't really the place for it but I stumbled on your thread. I just scored 4 lbs of this stuff. I have never used it but bought it because it was available and I do load a lot of .357s

Can anyone refer me to load data for 158 grain LSWCs? I have certainly googled it but I am looking for published data.

 

[Schwing]

I forgot to mention that I also will be shooting these through a GP100 5"... I would be interested in your findings.

 

[RealGun]

Can anyone refer me to load data for 158 grain LSWCs? I have certainly googled it but I am looking for published data.

Alliant lists 4.8 gr Bullseye or 6.0 gr Unique, both max numbers and close to the 1000 fps mark. As you probably know, higher velocities with specific lead bullets and other powders are always the province of the private reloader. The load for 158 gr Speer GDHP (jacketed) will give you an idea...PowerPro 300-MP 18.6 gr max at 1686 fps. There is a 700 fps spread between the families of loads.

There are loads for more powders for the 158 gr bullet on the Alliant website.

 

[RealGun]

Hornady 9th Edition has PowerPro 300-MP loads in its .357 Magnum chapter. The lead loads are only for subsonic velocity, not surprisingly.

Lyman Cast Bullet Handbook is invaluable for higher velocity lead loads. It does not include PowerPro 300-MP, but that powder is better suited to jacketed bullets.