Turning the 38 short colt into something more than a relic

[FastHands]

I’ve gotten myself into a adventure
A interesting one at that.
I’ve always loved the .357mag with a passion. If my owning 17 of them doesn’t prove it I don’t know what will. The capability to have the powerful magnum while also being able to use the less explosive and less expensive 38 special. But I want something a little different. I got my hands on some 38 short colt brass. I’m so intrigued by the little things. I’ve gotten good results with a 9mm charge of titegroup and a 148gr wadcutter that’s loaded to the same length as your typical 9mm. Pretty fair accuracy and light recoil and from what I can tell decent ballistic performance. One problem, I believe the pressure might be a bit much because I’m getting primers backing out.
What I’m looking for is to make my own little wildcat, a 357 short mag.
Nothing crazy but people are better at crunching the numbers than me.
What would be a better powder because I’m sure there is.
Or is the whole plan a accident waiting to happen ?

[35remington]

The long jump the bullet has to make through the oversized cylinder before it hits the cylinder throats makes it an increasingly bad idea the higher the chamber pressure gets.

As in….mega blowby gas cutting and cylinder leading.

[FergusonTO35]

From what I understand, it used to be common for competition shooters to use .38 SC brass for faster reloads.

[smkummer]

Factory 38 short colt used a heeled outside lube bullet of a .375-.378 diameter. This was intended for 19 century pocket revolvers that had straight bored through cylinders. Or cartridge conversions of cap-n-ball revolvers. The reason it and the old 38 long colt with a hollow base bullet works in a 38 special or even .357 chambered revolvers is that the low powered heeled bullet will downsize to the throat diameter in the cylinder and be suitable for the .357 bore.

What you are trying to do is maybe make a 9mm pressure wise round do a longer than normal bullet jump to the throat. The best you can hope for is acceptable accuracy with out excessive fouling buildup. It’s true that less powder will make the same pressure as a longer case with the same bullet. I don’t know that result will be worth the effort. You will also need special dies for some of the operations.

[Tokarev]

Why invent a whole new case when there is 38 spcl that can be downloaded to any desired pressure/velocity by using appropriate powder? I used as low as 2.5gr of Universal or Unique in a 380 long revolver case behind a 110gr bullet. Never had detonation issues but some unburnt powder due to the lack of crimp.

[Silvercreek Farmer]

I think the short round in long chamber concerns may be a bit overblown. 44 Russians shot quite well in my 44 mag. I bumped the charges a bit over 44 Russian levels, but stopped around 45 ACP levels.

Are your backed out primer cases sooty? Backed out primers are usually from low pressure rounds not producing enough case head thrust to reseat the primer. The long jump to the throat could be leaving you with low pressure. Do you have a chronograph? If not, you should probably get one if you enjoy going “off the reservation”.

Watch your seating depths, a deep seating a heavy bullet will significantly raise pressures. You may also run into problems hitting the taper towards the case head. This will swage down the base of your boolit and leave it undersized.

I’ve messed with 158 gr 9mm loads and 38 Short Colts a bit and never really came up with anything better than the standard loads. Really enjoy 38/44 loads, though. Good luck. Work up slow.

[imashooter2]

From what I understand, it used to be common for competition shooters to use .38 SC brass for faster reloads.

Still is. For new moon clip guns, the 9mm has taken precedence. For folks already invested, or those that want to shoot speed loader classes, short Colts lose nothing.

[imashooter2]

FWIW, I shoot Long Colt brass with the Lee 150 grain round nose. The deep seating of the Lee boolits along with the crimp groove make a slick package that is only about .030 longer than the short Colt guys. My load is a published +P load for .38 Special, which I suspect is well over +P in the long Colt cases. No leading or excessive chamber fouling in my 627.

[FastHands]

I understand it doesn’t have many advantages over either 357 or 38 but the bullet has peeked my interest. May I ask does anybody know a load that is equivalent to the original power of the bullet. Just so I have a baseline

[Harter66]

I say stupid stuff all the time because I way over simplify things that most folks that have worked the 380/9/38/357dia and slugged a few of them should pick up on pretty quickly . Sometimes it's so obvious that it just doesn't make any sense at all and someone else needs to explain it in a more complicated way .

So 9x17/19/21/23/25 are all basically the same .355-.357 groove dia as 38/357 and 38 Short/S&W/Colts NP/38-200 , Long and 9x18 share the fatter .361-.365 dia .
Logic follows that if the case is basically straight the load data for a particular case length isn't really going to care whether or not there's a rim on the case or not .
See 45 ACP , AR , data for reference . Seriously we can pop off a 223 case at 1.285 stuff it with a 158 gr bullet , 357 data and as long as it has release room and doesn't jump the chamber step it's a 357 mag .

So to the original question why make this harder than it needs to be shoot a slow powder with a shallow HB bullet in ACWW at 35kpsi just like the assorted 9s and 357 and keep the crud ring brushed out and your golden .

Or you can buy a Ruger BlackHawk or Vaquero in 357 convertible pick up a couple of spare 9mm cylinders and chamber them for whatever makes you smile . Heck for $200 Ruger would probably cut and fit a 38 Short cylinder especially for a convertible .

I'm probably working to hard at this .......

A JM 1894C will feed anything as long as it's at least 38 Special WC length and not over 357 length so a Lee 357-124 TLTC in a rimmed 9×25 will allow 14 rounds in the 10 round 357 mag and shoots pretty well it did get a little lead ring right at the chamber step though . Basically I had a few nickle 357 cases with mouth cracks and cut them back just to see . The first 12 went through the Ruger SS Sec 6 .

Good shooting .

[35remington]

The Short Colt case causes a lot of jump with a bullet having more than ten thou clearance between bullet and cylinder wall per side if you plan on using conventional .358ish bullets of lead construction.

To explain, my negativity on the practice comes from shooting 32 S and W in a 32 Long cylinder. That’s low pressure with less jump than you are contemplating. A jacketed bullet would be less obnoxious in terms of fouling but I fear that high pressure gasses and lead bullets with plenty of distance for blowby would result in some tough cleaning chores.

[FergusonTO35]

I wouldn't always count on bullet jump always creating poor accuracy. I have seen an awful lot of .22 LR rifles and revolvers that shoot extremely well with .22 Shorts.

[35remington]

The thing is 22 Shorts don’t have the slop in the long rifle chamber that we are dealing with here. In that instance bullet diameter with the 22 is much closer to chamber diameter.

[FergusonTO35]

Hmmm, did not know that.