A more efficient .38! Step inside for some edjumacation!

[okie john]

**Dumb Question Alert**

All my cast lead reloading has basically been for plinking, nothing too serious.

Wouldn’t a heavy crimp like you describe have the potential to deform/shave the bullet more on firing perhaps allowing more chance of leading? I recall somewhere reading about crimping and shaving, maybe it was with coated bullets (???). Thinking at it further, it would also seem that if there WAS shaving from the crimp, that the pressure and obturation would turn around and negate that...

Something that has been clanging around in my brain for a long time now... insights?

It's no problem to apply a heavy roll crimp IF the bullet has a proper crimp groove like this one.



Even a shallower groove like this one can work, you just can't crimp as deeply.



But if you crimp deeper than the groove allows or you crimp outside of the groove, then you will damage the bullet. Same if you crimp a bullet that doesn't have a groove like this one.



Those you have to crimp over the bullet's leading edge. You can also apply a roll crimp over the leading edge of any bullet. It looks odd but it works.


Okie John

[okie john]

Is it possible to roll crimp 45 ACP? Everything I read says a taper crimp should be used. You must be talking about 45 ACP and revolvers. I'm interested in this as I have a 625-8 and I might do some experimenting with the crimps. My understanding is the case still head spaces on the case mouth as it's possible to use the 625 without moon clips. Am I wrong? I need to look at the cylinder now, very curious.

I experimented with crimp a in S&W Model of 1989 several years ago.

Headspace can vary on S&W 45 ACP revolvers, going all the way back to the original 1917. Some won't fire 45 ACP ammo without moon clips. Mine would, but once I realized that it and my 1911 required different loads for best results, I switched to 45 Auto Rim brass in the revolver to avoid confusion. My RCBS 45 ACP die has a roll crimp shoulder but I had to screw it really deep into the press for it to work. Unfortunately, that gave the cartridge a very heavy taper crimp long before it reached the roll crimp shoulder. That sized the driving band down several thousandths and accuracy was non-existent. I had a buddy cut the bottom 1/2" or so off of an extra 45 Colt crimp die, which game me a roll crimp without the taper crimp. Groups shrank dramatically and velocity became much more consistent for the reasons that Lost River has stated.

I ultimately sold that revolver because I was trying to consolidate things and that left me with another cartridge and another type of brass to manage. Also, despite having a full underlug, it weighed less than my 4" Model 29-2, so it kicked harder with similar loads.

It was a nice revolver but can't say that I miss it.


Okie John

[Borderland]

I experimented with crimp a in S&W Model of 1989 several years ago.

Headspace can vary on S&W 45 ACP revolvers, going all the way back to the original 1917. Some won't fire 45 ACP ammo without moon clips. Mine would, but once I realized that it and my 1911 required different loads for best results, I switched to 45 Auto Rim brass in the revolver to avoid confusion. My RCBS 45 ACP die has a roll crimp shoulder but I had to screw it really deep into the press for it to work. Unfortunately, that gave the cartridge a very heavy taper crimp long before it reached the roll crimp shoulder. That sized the driving band down several thousandths and accuracy was non-existent. I had a buddy cut the bottom 1/2" or so off of an extra 45 Colt crimp die, which game me a roll crimp without the taper crimp. Groups shrank dramatically and velocity became much more consistent for the reasons that Lost River has stated.

I ultimately sold that revolver because I was trying to consolidate things and that left me with another cartridge and another type of brass to manage. Also, despite having a full underlug, it weighed less than my 4" Model 29-2, so it kicked harder with similar loads.

It was a nice revolver but can't say that I miss it.


Okie John

I keep getting bullet creep with my 625 so I'm looking for solutions. I apply a heavy taper crimp and that eliminates it for the most part but I still see some creep. I may have to go back to FMJ bullets exclusively. Coated lead isn't working out real well. I like the revolver enough to keep it. I just put a Vortex red dot on it.

[okie john]

I keep getting bullet creep with my 625 so I'm looking for solutions. I apply a heavy taper crimp and that eliminates it for the most part but I still see some creep. I may have to go back to FMJ bullets exclusively. Coated lead isn't working out real well. I like the revolver enough to keep it. I just put a Vortex red dot on it.

One of the best things about a 45 ACP revolver is the ability to use inexpensive lead bullets. But that demands a roll crimp like Elmer Keith described before WWII, especially as bullet weight increases.

Pretty much any machine shop should be able to shorten a 45 Colt sizing die, or a gunsmith might be able to open up a 45 ACP taper crimp die enough to remove the taper crimp function but leave the roll crimp shoulder. I don't know if that would be optimal or if there's enough of a shoulder there to get you as much crimp as you need. In either case, modifying a die only has to be done once and it's far cheaper in the long run than switching to jacketed bullets, especially if current shortages continue.

I'm not sure, but lighter bullets might not creep as much in a taper crimp.


Okie John

[41magfan]

There's a guy in these parts who cut down a 686 cylinder to take .38 Short Colts and machined a barrel with an extension to the now-shortened cylinder. The picture I saw of the gun looked nice and I only met the guy one time over two years ago.

(We chatted because I was the only one shooting a revolver at an outlaw IDPA match.)

I could be wrong, but I think this is the guy that might have pioneered the short cylinder concept ....

[okie john]

I could be wrong, but I think this is the guy that might have pioneered the short cylinder concept ....

Elmer Keith's book Sixguns has a picture of a S&W 1917 done that way. It was published in 1955, so somebody was doing them before that.

I'll see if I can find my copy.


Okie John

[TicTacticalTimmy]

I never realized that .38sc is about the same length as 9mm Luger.

Does anyone know if one can get 9mm velocities with less powder than would be required in a .38/.357 case? I would think so, and if so it truly would be a more "efficient" cartridge in terms of less recoil and muzzle blast, without any of the potential drawbacks of 9mm in a revolver.

What would have less recoil? A 9mm LCR throwing a 124gr at 1000 fps or a .357 lcr loaded with .38sc throwing a 125gr at 1000 fps?

[Caballoflaco]

@Bruce Cartwright

I wonder if Cotterman’s experiments are what led to the short lived 9mm Federal I asked about on here a few weeks ago?

https://pistol-forum.com/showthread....deral-(rimmed)

[Spartan1980]

I keep getting bullet creep with my 625 so I'm looking for solutions. I apply a heavy taper crimp and that eliminates it for the most part but I still see some creep. I may have to go back to FMJ bullets exclusively. Coated lead isn't working out real well. I like the revolver enough to keep it. I just put a Vortex red dot on it.

Without a cannelure or shoulder to crimp over there is no cure for bullet creep, at least not that I've ever found. The 625 will teach you really quick that crimp doesn't hold a bullet in place and neck tension to do so is not workable, this gun is just a kinetic bullet puller and there's no getting around that. Except....

I have pics somewhere in the depths of my computer that I can't find right now but I was able to get some unbelievable consistency out of my 625 by eliminating the bullet pull. The pics are the rounds and the chrono card at the Memphis Charity Challenge. At chrono in USPSA they fire three rounds over the chrono. Two of my rounds were the same number. The other was 3 FPS different. The guy finished up and asked "what the hell kinda powder are you using?" I told him Clays.

What I did was load 200 grain RN from Bayou Bullets seated very deep, as in past the shoulder, the shoulder down inside the case kind of deep by about .030" or so. I then heavily roll crimped over that shoulder with a Redding profile crimp die. They looked silly almost like simunition rounds. That was probably 95% of it, the rest would have been the sorted by headstamp brass and Federal GMM primers. I worked up this load specifically for this match. It wasn't a chrono fluke either because I did the same EXACT variance with that batch of ammo at the Area 4 Championship the next year. Two shots same velocity, the third 3 FPS different.

I've not found a bullet that will stay put without extravagant means at the loading bench in this gun.

[Borderland]

Without a cannelure or shoulder to crimp over there is no cure for bullet creep, at least not that I've ever found. The 625 will teach you really quick that crimp doesn't hold a bullet in place and neck tension to do so is not workable, this gun is just a kinetic bullet puller and there's no getting around that. Except....

I have pics somewhere in the depths of my computer that I can't find right now but I was able to get some unbelievable consistency out of my 625 by eliminating the bullet pull. The pics are the rounds and the chrono card at the Memphis Charity Challenge. At chrono in USPSA they fire three rounds over the chrono. Two of my rounds were the same number. The other was 3 FPS different. The guy finished up and asked "what the hell kinda powder are you using?" I told him Clays.

What I did was load 200 grain RN from Bayou Bullets seated very deep, as in past the shoulder, the shoulder down inside the case kind of deep by about .030" or so. I then heavily roll crimped over that shoulder with a Redding profile crimp die. They looked silly almost like simunition rounds. That was probably 95% of it, the rest would have been the sorted by headstamp brass and Federal GMM primers. I worked up this load specifically for this match. It wasn't a chrono fluke either because I did the same EXACT variance with that batch of ammo at the Area 4 Championship the next year. Two shots same velocity, the third 3 FPS different.

I've not found a bullet that will stay put without extravagant means at the loading bench in this gun.

I'm going to try some 200 gr FMJ bullets. If that doesn't work I'll try something else. That's half the fun of reloading. I would like to find one load that works in my 625, my HK-45 and my Gold Cup. Probably never get there.