How do you make 10mm Auto Rim? From 30-30 Winchester? Fire forming?

How do you make 10mm Auto Rim? From 30-30 Winchester? Fire forming?

I have a Smith and Wesson model 610 revolver which shoots 10mm and 40 S&W. It uses moon clips. I thought it would be nice to shoot some 10mm Auto Rim also. Like .45 Auto Rim is to .45 ACP. I could not find any.

I have a few pieces of 30-30 Winchester brass so I thought I would make some 10mm Auto Rim. I cut the 30-30 brass down to size using a hack saw blade and a drill press.

But my bullets do not quit fit. Can I fire form this in the revolver to get the brass to fit the bullets? Can I cookie cutter some wax to use as bullets to fire form it? Or maybe there is another way?

What about using a 10mm expander / powder through die to bell the cases a tad? Would you have to stretch them too far?
If all else fails, you could send the 30-30 cases to me and buy some 10mm Auto Rim

I've never tried to fire form trimmed down rifle cases for pistol brass or pistol brass.

Something I would check first... Measure the diameter of the 30-30 case just above the rim...if this area is too small of a diameter(smaller than a 10mm case wall) I would hesitate to try fire forming them out.

It might be possible, I'm just afraid of case fractures in that area could result from being over expanded.

Note: Normally cases are annealed when cartridge converting. Just the neck and shoulder to reduce the chances of splitting or folding. annealing the cartridge base and body is usually a no no.

I put a primer in one of the sawed off cases and loaded it (just a case and primer, no powder, no bullet) into the S&W 610. That’s safe to do inside the house, right?
When I smoothly and lovingly pulled the trigger all I got was “Click”. The firing pin did not reach the primer. The rim on the 30-30 brass is way too thin to get the primer close enough to the firing pin.

That sucks man. I was looking foreword to a new 10mm Edgar wildcat.

Since 10mm headspaces on the mouth I think I can make the next batch longer and maybe that will work.

have you thought of maybe using an o-ring between the case rim and the cylinder. Seems to me you need to take up space that would be occupied by the moon clip. any way that is a trick that's often used by 303 British shooters when excessive head space pops up on their en-fields. don't see why it wouldn't work on your revolver.

I think ammosmith is working on this problem. Why not drop him a line?

Looks like Ammosmith is doing 10mm Bullet Swaging.

A quick look back at Ammosmith videos, I did find only this... https://www.youtube.com/watch?v=FzG8EskAiNc He mentions working on the problem at about 5:20 into the 11 minute video. He does have some ideas, but does not elaborate.

Reload3006 wrote:have you thought of maybe using an o-ring between the case rim and the cylinder. Seems to me you need to take up space that would be occupied by the moon clip. any way that is a trick that's often used by 303 British shooters when excessive head space pops up on their en-fields. don't see why it wouldn't work on your revolver.

I tried the o-ring today and it worked. Thanks!

wallenba wrote:A quick look back at Ammosmith videos, I did find only this... https://www.youtube.com/watch?v=FzG8EskAiNc He mentions working on the problem at about 5:20 into the 11 minute video. He does have some ideas, but does not elaborate.

Good idea. I sent him a message asking how to ream the 30-30 brass since it is be thick. After you put in a bullet the cartridge is too big around to chamber.

I am planning to try to fireform the trimmed 30-30 cases in my S-W 610 revolver.
I plan to cut out some wads from cardboard using the trimmed 30-30 case as a cookie-cutter. Then put 10 grains of Bullseye in it and cover it with the cardboard wad and drop the hammer on it.

Will it work? Should I anneal the cases first?

It wouldn't hurt it to anneal because it could prevent it from cracking. I am not sure that a Wad will develop the pressure you need to fire form. you may want to use a light bullet.

I hadn't caught that you couldn't get the bullet to fit ... because of the thickness of the brass. Gosh I don't know if fire forming them will "Thin" the brass. you may need to turn them. That aside a cardboard plug will not develop enough pressure to fire-form the brass. you may try to use the Shot-shells that Mo made approach maybe it will develop enough pressure to do what you want.

Summary: The firing pin could not reach the primer. The O-ring did work but it looked so worn after just one firing (with just a primer, no powder, no bullet) that I did not think it would last. So I cut the 30-30 case a little longer and now I do not need the O-ring. The cases I just cut now headspace on the mouth at the shelf in the chamber, just like the 10mm cases do.

Details:
1. I cut the 30-30 cases with a drill press and a pipe cutter. I used a Lee Universal Three Jaw Chuck to hold the 30-30 case in the drill press. That got the cases to the approximate length.



2. Then I used a Lyman Universal Trimmer to get the cases to the exact size I wanted.



3. I used the pilot marked 35 which was actually just a bit too small but seemed to work ok.



4. I trimmed them to .992 inch which is the maximum length for a 10mm case.



5. Here is what they look like in the revolver:





I don't think there is too much unsupported brass between the cylinder and the rim of the case, do you?