I am really hesitant about posting this question - but, here goes. I just picked up a Ruger LCR 9mm. It came with three moon-clips. Getting it reminded me that Federal loaded a 9mm rimmed round many years ago. Just for kicks and giggles, I've done a little bit of Oogling and can't find a source for the brass. No surprise there. I've also looked at my SAAMI specs PDF and the only thing sorta-kinda close, case-wise, I can find is .38 S&W.

It looks like .38 S&W cases could be safely fire-formed (after trimming) in a 9mm revolver. 9mm P cases, should be .391 in front of the extractor groove - SAAMI says .38 S&W should be .386 - so 5-thousands difference. If I were to try that - I would fire-form them in my Ruger Blackhawk and use very mild loads. The problem, though, is that the .38 S&W rims may be too large to work in the LCR 9mm. And, even worse, there might be some serious head space issues due to the thick rims on .38 S&W. I'm just wondering if anyone else out there has ever thought about this or tried it?

This is just a mental exercise right now, which is very difficult for me ... . I have the time to trim down case length on some cases to get them to work - but I don't have the tools, patience, or skill-set to attempt to turn down case heads. I just thought I'd mention this - maybe there is an easier way to to it. It would be nice to use the LCR without moonclips and it would give me a project to work on to keep me out of the bars...

Edited to add: I got started in the whole case-forming business years ago by using 9X21 brass to form and load .30 Luger. I had found, and subsequently sold, a .30 Luger Hi-Power barrel and wanted to form cases for it. I still have a Ruger P-89 Conv in .30/9mm + a Walther P5 with both barrels...

The cartridge was called a 9mm Federal, and was very similar in appearance to the .38 S&W. I think the only handgun which ever chambered it was a revolver from Charter Arms. Analogous to the .45 ACP vs. .45 Auto Rim. It hasn't been loaded for many years, and you are unlikely to find any brass for it. I believe the 9mm Federal was dropped due to a few Ka-Booms by those who used it in some old .38 S&W top break revolvers.

I would also think that it would be possible to re-form .38 S&W or .38 Short Colt brass (or maybe even shortened .38 Special brass) into what is essentially the 9mm Federal case by resizing in a 9x19mm FL die.. Try it and see.

I also checked the current SAAMI specs, and can't find anything there about the 9mm Federal. And it is not shown in Donnelly's handbook of cartridge conversions either. I would think that rim thickness might be more significant than rim diameter. The .38 S&W rim SAAMI maximum thickness is 0.055" while the .38 Special, etc., is 0.059". You might also consider using a shortened .38 Super case as a 9mm Federal surrogate as it has a thinner maximum rim, 0.050". And it has enough of a rim diameter (about 0.034" less than the .38 Special rim) to extract and keep the case from falling into the chamber. Shouldn't be any rim interference with it.

I use 38 s&w cases shorted of coarse works very well. My 905 drops them just like any other revolver.

I have an article no longer on the net but from a source I trust about shooting cast in the Ruger Blackhawk 9mm convertible. He mentions trimming Federal 38 Special cases to 9mm length with either a cut off saw or a trim die then finishing with a forester trimmer. Chamfer and size with a 9mm die and a 38 Special shell holder. My cylinder does not have the clearances to do this but it could be done if one wanted to.

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Front sight and squeeze

Gents - Thank-you for the input! Hollywood - I think the case diameter difference is only around .005-ish - but, have you had any bulged cases? I just found that Midway sells .38 S&W cases by the 100 - and the Lyman EZ-Trim case trimmer is only $20-something. I did drop two .38 Short Colt rounds into adjacent chambers and there's adequate clearance between the case heads. My other concern was that the case heads might cause hand or pawl clearance issues - but if they work in the 905 hopefully ... maybe they'll work OK in the LCR. I can't test cylinder carry-up (for potential clearance issues) because I only have loaded/factory .38 Short Colt rounds ... and the LCR is a DAO ...

Will the .38 SC cases fit into the chambers without trimming the length? Having no idea of the case dimensions of the 9mm Federal, I would think the .38 SC might be a better fit than the .38 S&W. And I think Starline also makes .38 SC cases, but I haven't looked recently.

Thanks, again, for your input, Gents! I won't bump this thread again until I've received the .38SW brass and case-trimmer doohickey. The base dia of 9mm is .391, .38 Short Colt is .379 and .38SW is .386. .38 Short Colt would prolly work but it would expand roughly .012 in firing. .38SW is closer with only .005 expansion required - plus hollywood63 has used .38SW cases in his 905 (Taurus - I think).

.38 Short Colt (Rem 125-g Lead RN) drops into the LCR chambers just fine, and there is plenty of clearance around the case heads. That said, the rounds rattle in the chamber given the .012 undersizing of the .38SC cases in the 9mm chambers. And, the .38SC cases are too long, even if they fit fine (because they are undersized, I assume). There might be some pressure issues if a person attempted to fire full-length .38SC in a 9mm chamber - I dunno for sure. If I still have five fingers on each hand, I will report back after firing a few rounds ...

Added: Kind of a crummy photo - but the .38SC rounds fit just fine - although the clearance around the extractor looks tight. The SAAMI spec for rim diameter for both .38SC, .38/.357 and .38 S&W is .440 - so all four rounds have the same rim diameter.