Loading .38 SPL, only using .357 brass instead

[Amistad]

I "think" I loaded a few rounds of .38 SPL like this a few years back. I seem to recall making some brief notes about the project, but darned if I can find them now.

I really like shooting 148 gr Cast DEWC as .38 SPL rounds in my .357. I seat the bullets almost flush with the case mouth. I guess I've shot a couple thousand loaded like that and they make nice, crisp holes. Very fun to shoot! But I can't remember just what modifications to allow for when using .357 brass instead. Any insight that you might like to pass along to me? Thanks!

Amistad

 

[tsubaki]

I'm using that bullet with 38spl cases for 38spl and 357mag in target rounds with 3.0gr of Bullseye seated the same way you describe.
I can't imagine or understand what modifications might be necessary for the 357 brass.

 

[Amistad]

My use of "modifications" was a poor choice of wording. As I think more on it now, I was thinking that since the case of the .357 is longer, there would be a need for a bit more powder in the longer case, due to more of an area for the gas to expand in. I look back now and am fairly sure that I used 2.8 gr of Bullseye when loading with .38 SPL brass, and then when I switched to using .357 cases, I boosted the Bullseye charge to 3.2 gr. That's close to your number. Thank for the reply.

Amistad

 

[No-1]

The overall length of where the powder is expanding is the same - from the back of the shell to the front of the barrel.

 

[loaded round]

FWIW, when I started reloading some 45 years ago I was loading 148 gr wadcutter bullets in both 38 Spl and 357 Mag cases in my OM 357 Blackhawk. The load was 2.7 gr of Bullseye in the 38 cases, and 3.0 gr in the 357 cases. I would crimp both loads at the top crimping grove and not seat the bullet flush since I was shooting them in a revolver. I still load the same bullet and the same powder weight but seat them flush in the 38 case to shoot in my Smith Model 52. Most accurate center fire pistol load I have ever used.

 

[Bucks Owin]

The overall length of where the powder is expanding is the same - from the back of the shell to the front of the barrel.

?!? :shock:

 

[WIL TERRY]

The overall length of where the powder is expanding is the same - from the back of the shell to the front of the barrel.

YOU'D BETTER RETHINK THIS as it is fundamentally wrong.

It is SEATING DEPTH in the two different length [ 1.160 vs 1.285" ] cartridge cases that makes ALL the difference in the world.

 

[WIL TERRY]

FURTHEREMORE, after testing literally tens of thousands of 38SPL WC loads I started in on the same in the 357MAG cartridge for ALL of my 357MAG pistols. NOTHING, AND I DO MEAN NOTHING, outshot the singular load of 4.0grs of BULLSEYE under just about any 38WC bullet you care to choose. The DEWC .3585" O.D. bullets with that noted load were just all but unbeatable in all the 357MAG sixguns I tested with BBL lengths from 2 1/2" to 8 3/8" and just about every damnstop in between. Velocites ran right at 850- to 900fps and would just smack the stew outta small game.
And so it goes...

 

[WESHOOT2]

Ditto Mr. Terry; I use 357 Magnum cases.
Data abounds.

 

[Ale-8(1)]

I just yesterday shot a box of 148-gr DEWC loaded over three grains of Unique in .357 cases. Nothing spectacular, but quite consistent thru a four-digit .357 Flattop.

And dirty, of course . . . it was Unique, after all.

And the Bullseye loads have proved good as well, but these had been sitting in my cabinet for like twenty years and I thought I ought to see if they still went "bang".

Yep, for sure.

 

[Chuck 100 yd]

The Lyman cast bullet manual #14 has many loads like you want.

 

[Amistad]

Many thanks for the replies, gents.

Amistad