.38 Special loads in .357 brass?

[Snapping Twig]

+1 on the 5g W231 under a 160g cast in a magnum case.

Been my load forever.

Shoots nice, has enough accuracy and smashum, light recoil.

 

[chriske]

As far as "regular pressure" .38 Spl. loads go ("NON Plus P"), suitable for plinking & target shooting, I simply increase powder charge by 10 % for use in .357Mag brass.
For instance my .38 Spl. target load for 148 Gr. HBWC bullets is 3.1 Gr of W-231 . This becomes 3.4 Gr of the same powder in the longer case.
Ditto 4.3 Gr. of W-231 behind a 158 Gr. LSWC in .38 Spl. becomes 4.7 Gr. in .357 Mag cases.
Works for me.

 

[TSQUARED]

I have a pre WW II 357 Registered magnum which was used in bullseye pistol matches for many years with the old standard load of 2.7 gr. Bullseye behind a 148 gr. LWC in 38 Special cases. The gun was always cleaned after shooting so carbon residue did not pile up in the chambers. It was then and still is a superbly accurate 38.

 

[Jimmymac46]

I too am amazed, doesn't anyone use Unique anymore? I have been reloading for over 40 years (started in college back in the late 60's) and after trying a number of different brands, speeds and manufacturers, I settled on Unique and Bullseye for all my 38, 357, 44 Special and 44 Magnum light and mid-range loads. While there are considerably more choices today, I personally find it easier and cheaper to retain fewer powders for all my ammo needs.

For the hot stuff, I finally gave up on 2400 in that it nearly alway left unburned powder in the barrels of my revolvers. When I started using H-110 and 296 (only 25 years ago), that problem was solved. Just my two cents worth.

 

[leas327]

+1 on using IMR Trail Boss
It is a very bulky powder that fills a lot more of the case. It was made for cowboy action shooting to fill cases and be easy on guns/recoil. It has a very similar burn rate to tite group but is 3 times bulkier. If you look at a can you will see that it is only contains 9 oz. in a standard 1 lb. can. I also like it because it would be very easy to tell if I double charged a case.
I have never used Unique but I work with a couple guys that swear by it for light loads.

 

[bmcgilvray]

OK, somebody's gotta do it.

I use 5.0 grains of Unique under a cast 158 grain SWC in .357 Magnum cases for a rough duplicate of standard velocity .38 Special ammunition. Clocks around 885 fps from my six-inch Model 27 and gives great accuracy.

While there is not a thing in the world wrong with it I never shoot .38 Special ammunition from my .357 Magnum revolvers, choosing to only use loads put up in .357 cases.