Handload suggestions for Trooper Mk III 357 mag


October 10, 2011, 05:14 PM
The title says it all. I just found a trooper and am interested in what ya'll have tried that works well. Also can this revolver take the magnum loads exclusively or should I give it a breather and use 38 specials more often.

I had a 357 years ago it was a security six. I do remember that it was quite loud and recoiled quite a bit with the mags. I did not roll my own back then but do now and am looking for tips.


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October 10, 2011, 05:26 PM
My favorite .357 powder is Tightgroup. I also like it for .38's but I prefer A#5 for that. I would shoot whatever you want out of it. It is made to shoot both. I like Missouri Bullet Company for 158gr LSWC and Sierra's 140gr JHC.

October 10, 2011, 05:33 PM
The Trooper Mk III is about as strong as it gets.

It was redesigned with simpler lockwork from the older V-Spring Python & Trooper and is very likely a stronger gun.

Any sane .357 Mag load is going to be fine.

I shoot a slightly reduced Magnum load in my K-Frame S&Ws consisting of:
Any brand case
Standard SP primer.
140 grain Hornady XTP.
14.5 grains Alliant 2400.

It is 1 1/2 - 2.0 grains under MAX according to some published data, and your gun will last longer then you likely will.

I do not recommend any very fast powder like Tight-Group, Bullseye, Red Dot, etc. in Magnum loads, as pressure can spike very quickly and dangerously if you push it too far.
And too far isn't very far when the difference between a start & MAX load is only 1/2 a grain!

It is difficult to get in trouble with Magnum loads using slower powders designed for magnum loads, like 2400.

Truth be known though, I have always shot about 50/1 more .38 Special then .357's in my .357's.
They are just a lot of fun!


October 10, 2011, 05:55 PM
What RC wrote about the fast powders is something to keep in mind, especially with heavier bullets.
I was trying to see if I could find a load so I could get a bunch of Red Dot used up with the 158 grn cast bullets I like to use.
Found a 5 grn load, but it felt pretty slow, don't have a chrono. and bullets I dug out of the soft dirt where I shoot were hardly deformed.
So, I loaded up a few at 5 1/2 grns, instant flattened primers.
Guess that Red Dot gets put up on the shelf again.

evan price
October 11, 2011, 02:38 AM
Fast powders like Red Dot, Titegroup, Bullseye, etc. will work fine in 357 Magnums as long as you do not expect the top-level velocity.

I load 5.0 of Titegroup with 158-LSWC in my 357 Magnums, that's 1100 fps or thereabouts. Not a barn buster but it's great for target shooting- paper don't care if the bullet goes 1100 or 1500, it all makes a hole.

I tried 5.5 gr of Titegroup- got me sticky brass and it got backed back down to 5.0 grains.

If you must have real Magnum speeds you must have a real Magnum powder- AA#9, 2400, H110/W296, 4227, etc. and they usually want a Magnum primer too.

October 11, 2011, 03:05 AM
I use HS-6 or W296 for my .357 Magnum loads.

Nothing wrong shooting .38 Special ammo in that revolver either.

October 11, 2011, 04:21 AM
You can feed a MK III all the Magnums you want. You hand will wear out before it does.

October 11, 2011, 04:29 PM
For just range & plinking I'd go with moderate loads. Something like a mid charge of H Universal, or other similar powder would work. Many choices available.

October 11, 2011, 06:07 PM
I never had a problem with tightgroup

October 12, 2011, 11:15 PM
Thanks to all of you for the info!

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