Bullwolf
09-12-2016, 12:04 AM
I'd often wondered if I could make rimmed 10mm cases for my Smith and Wesson 610 revolver.
http://castboolits.gunloads.com/attachment.php?attachmentid=53320&d=1332375253
Mainly I wanted be able to shoot the revolver occasionally, without having to use full moon clips.
In my first attempt back in March 2014, I tried to make rimmed 10mm from trimmed down 30-30 Winchester cases. It had a few drawbacks though. To name a few, I was stuck using Large Rifle Primers with the 30-30 Win cases, and the trimmed sized cases had less internal capacity, along with thick necks and rims.
I wrote a little bit about the 30-30 Winchester case attempt in this older thread.
http://castboolits.gunloads.com/showthread.php?235186-10mm-Auto-Rim&p=2692688#post2692688
I wasn't all that happy with how the trimmed 30-30 Winchester cases turned out, though they did fit it in the cylinder, and I could successfully fire the large rifle primer in my Smith 610. I never loaded any trimmed/sized 30-30 Win cases, scrapping the whole idea and I went back to the drawing board.
Now fast forward to a few years later. I decided to revisit the rimmed 10mm case using trimmed and slightly harder to form (size down) 41 Magnum/Special brass.
http://castboolits.gunloads.com/attachment.php?attachmentid=99965&d=1403162239&thumb=1 http://castboolits.gunloads.com/attachment.php?attachmentid=99964&d=1403162239&thumb=1
As said in the previous thread, I wasn't doing anything new that had never been done before. Others have used the same method (trimming & sizing 30-30 Winchester or 41 Magnum cases) to form the Herters 41 Power Mag which has very similar dimensions.
http://castboolits.gunloads.com/attachment.php?attachmentid=99963&d=1395218560
Since 41 Magnum brass is still somewhat rare and special to me, I started out using virgin unfired Starline 41 Special brass instead. This gave me a bit less case length to trim, and a Special or SPL head stamp.
176430
Trim length for me was a bit of trial and error. I ended up trimming on the longer side for 10mm (.995 inch) which resulted in perfect head spacing on the case mouth in my revolver cylinder. Cases trimmed shorter than this would only head space in the cartridge rim. I trimmed all the cases AFTER sizing of course, giving my old RCBS case trimmer quite the work out.
176431
Sizing the brass down from .435 to my target dimension of .425 took two passes. My first pass was full length sizing a lubed case (I used Bag Balm) in an RCBS 40S&W/10mm Carbide sizing die, using a 41 Magnum shell holder.
(RCBS #30 Shell Holder for 41 Magnum/Special)
The first sizing pass got me close, but not close enough all the way down to the case rim. Full length sized cases would not fit in the revolver yet, and showed a bit of a bulge down at the bottom of the cases.
My second sizing pass (also Lubed) was through a 40S&W/10mm Lee Carbide Factory Crimp Die, with the crimping section removed much like when using it for bulge busting.
http://leeprecision.com/userfiles/images/38_FCD.jpg
This sizing pass was performed with out using the shell holder however. I used a block of hardwood instead to push the cases up into the die, all the way to the rim. Afterwards I ejected the (lubed) cases from the Lee CFC Die using a rawhide mallet, and a oak hardwood dowel.
176432
Doing it this way sized the 41 Special cases all the way down to the case rim. (no bottom base sizing bulge now) The trimmed 41 Special cases now measure .426 at the base after the Lee CFCD sizing step. The final size was a bit larger than I was shooting for, due to the larger Lee CFCD inside dimensions, but the cases now fit easily in the cylinder of my 610 revolver after the second sizing pass, so I called it perfect.
I only made around 59 cases (enough for me to fill a box with a few extras) as doing this was definitely a labor of love. I can easily make more later now that I know the steps.
My first loading of the brass is with a mild (40 S&W level really) 180 grain jacketed load, since that what the sights are currently regulated for. It's unlikely that I will lose any brass shooting a revolver, so it should be easy enough to load up box of cast 10mm Auto Rim whenever I want now.
The Finished product 10mm Auto Rim.
176433
Cartridge lineup (left to right) 10mm Factory JHP, 10mm Rimmed, and 40 S&W
176434
I found a pleasant secondary benefit of using the rimmed 41 cases. The 10mm Auto Rim cartridges happen to fit and function nicely through my 610 using HKS 57M speed loaders for model 57/58 41 Magnum Smith & Wesson revolvers.
176435
I know your probably asking yourself why someone would use a speed loader to reload a 10mm revolver with, instead of the much faster to use full moon clips.
Sometimes it's just nice to have options. If I want to shoot just a couple rounds, or even a whole box of ammo, and not have to moon it up and de-moon it afterwards... Well I can now now.
Anyhow, there you go. 10mm Rimmed from 41 Special brass, the hard way.
- Bullwolf
http://castboolits.gunloads.com/attachment.php?attachmentid=53320&d=1332375253
Mainly I wanted be able to shoot the revolver occasionally, without having to use full moon clips.
In my first attempt back in March 2014, I tried to make rimmed 10mm from trimmed down 30-30 Winchester cases. It had a few drawbacks though. To name a few, I was stuck using Large Rifle Primers with the 30-30 Win cases, and the trimmed sized cases had less internal capacity, along with thick necks and rims.
I wrote a little bit about the 30-30 Winchester case attempt in this older thread.
http://castboolits.gunloads.com/showthread.php?235186-10mm-Auto-Rim&p=2692688#post2692688
I wasn't all that happy with how the trimmed 30-30 Winchester cases turned out, though they did fit it in the cylinder, and I could successfully fire the large rifle primer in my Smith 610. I never loaded any trimmed/sized 30-30 Win cases, scrapping the whole idea and I went back to the drawing board.
Now fast forward to a few years later. I decided to revisit the rimmed 10mm case using trimmed and slightly harder to form (size down) 41 Magnum/Special brass.
http://castboolits.gunloads.com/attachment.php?attachmentid=99965&d=1403162239&thumb=1 http://castboolits.gunloads.com/attachment.php?attachmentid=99964&d=1403162239&thumb=1
As said in the previous thread, I wasn't doing anything new that had never been done before. Others have used the same method (trimming & sizing 30-30 Winchester or 41 Magnum cases) to form the Herters 41 Power Mag which has very similar dimensions.
http://castboolits.gunloads.com/attachment.php?attachmentid=99963&d=1395218560
Since 41 Magnum brass is still somewhat rare and special to me, I started out using virgin unfired Starline 41 Special brass instead. This gave me a bit less case length to trim, and a Special or SPL head stamp.
176430
Trim length for me was a bit of trial and error. I ended up trimming on the longer side for 10mm (.995 inch) which resulted in perfect head spacing on the case mouth in my revolver cylinder. Cases trimmed shorter than this would only head space in the cartridge rim. I trimmed all the cases AFTER sizing of course, giving my old RCBS case trimmer quite the work out.
176431
Sizing the brass down from .435 to my target dimension of .425 took two passes. My first pass was full length sizing a lubed case (I used Bag Balm) in an RCBS 40S&W/10mm Carbide sizing die, using a 41 Magnum shell holder.
(RCBS #30 Shell Holder for 41 Magnum/Special)
The first sizing pass got me close, but not close enough all the way down to the case rim. Full length sized cases would not fit in the revolver yet, and showed a bit of a bulge down at the bottom of the cases.
My second sizing pass (also Lubed) was through a 40S&W/10mm Lee Carbide Factory Crimp Die, with the crimping section removed much like when using it for bulge busting.
http://leeprecision.com/userfiles/images/38_FCD.jpg
This sizing pass was performed with out using the shell holder however. I used a block of hardwood instead to push the cases up into the die, all the way to the rim. Afterwards I ejected the (lubed) cases from the Lee CFC Die using a rawhide mallet, and a oak hardwood dowel.
176432
Doing it this way sized the 41 Special cases all the way down to the case rim. (no bottom base sizing bulge now) The trimmed 41 Special cases now measure .426 at the base after the Lee CFCD sizing step. The final size was a bit larger than I was shooting for, due to the larger Lee CFCD inside dimensions, but the cases now fit easily in the cylinder of my 610 revolver after the second sizing pass, so I called it perfect.
I only made around 59 cases (enough for me to fill a box with a few extras) as doing this was definitely a labor of love. I can easily make more later now that I know the steps.
My first loading of the brass is with a mild (40 S&W level really) 180 grain jacketed load, since that what the sights are currently regulated for. It's unlikely that I will lose any brass shooting a revolver, so it should be easy enough to load up box of cast 10mm Auto Rim whenever I want now.
The Finished product 10mm Auto Rim.
176433
Cartridge lineup (left to right) 10mm Factory JHP, 10mm Rimmed, and 40 S&W
176434
I found a pleasant secondary benefit of using the rimmed 41 cases. The 10mm Auto Rim cartridges happen to fit and function nicely through my 610 using HKS 57M speed loaders for model 57/58 41 Magnum Smith & Wesson revolvers.
176435
I know your probably asking yourself why someone would use a speed loader to reload a 10mm revolver with, instead of the much faster to use full moon clips.
Sometimes it's just nice to have options. If I want to shoot just a couple rounds, or even a whole box of ammo, and not have to moon it up and de-moon it afterwards... Well I can now now.
Anyhow, there you go. 10mm Rimmed from 41 Special brass, the hard way.
- Bullwolf