Homebuilt 10mm

[Sailormilan2]

Since I live on the left Coast in Sunny CA, where 10mms are hard to find, I decided to put one together. I located a ParaOrdnance slide with a breechface cut for 40cal/10mm rim, and a rather inexpensive barrel, and put one together using my RIA Tactical 45acp frame.
Once my taper crimp die got here, I loaded up some ammo using two different bullets and powders. Loads were a powder coated 175 gr SWC over 6.4 gr of Unique, and powder coated 180 TC bullet loaded over 12.7 gr WC820(basically AA#9). Barrel must have a tight chamber, because loaded uncrimped rounds that would drop into my Midway case gauge would not chamber more than 1/2 way.
I used a flat based firing pin stop, 23# mainspring, and 20# recoil spring. I am probably going to have to go up to 23# recoil spring, as empties were landing 20 feet away.
I was very surprised by the groups I got. I am out of practise, and yet they were decent groups. Better than what I expected for a $72 barrel.
Group 1, using midrange Unique load, shot at 10 yds, two handed hold.


Second group, using the WC820 load was fired at the same target as I wanted to see how much of a POI change there was.


Final group was 4 rounds from each load, total of 8 shots, fired from about 18 yds, supported.


The primers look like they might be flowing a bit, and the loads aren't that hot. I used an old Colt 9mm firing pin, and it might be undersized. Since I am using a ParaOrdnance slide, I think I will try to find a PO 9mm firing pin, and see if that changes any thing.


Today's shooting was merely to test everything to see how it functions, especially the barrel. If it wasn't accurate, then I was going to have to find another one. But it seems fine.
Just for giggles, I dropped my 9mm barrel into the slide and fired some shots at 10 yds. Using 124 gr ball, and about 5.5 gr Unique, POI went up about 4". I think I was save that barrel for the dedicated 9mm/38 Super slide that I have.
But, now to order a heavier spring. Right now, I can use my Rock Tactical for the 45acp it came with, then switch slides and barrels, and to to 9mm, 38 Super, and 10mm. I'm still debating on 40 S&W.

[00Medic]

Outstanding!!!

This is the same idea I have been running around in my head. I think I'll steal a few ideas from you.

[pdoggeth]

Cool thing you did!

Which leads me to ask you (or anyone with experience), would just getting a 10mm completed slide, 10mm barrel, and 10 mm magazines be sufficient enough to shot 10mm out of a 1911? You also mentioned different mainsprings.

If that's the case and it's so simple, then hell, maybe one day I'll do this myself too!

[Bill Steele]

Cool thing you did!

Which leads me to ask you (or anyone with experience), would just getting a 10mm completed slide, 10mm barrel, and 10 mm magazines be sufficient enough to shot 10mm out of a 1911? You also mentioned different mainsprings.

If that's the case and it's so simple, then hell, maybe one day I'll do this myself too!

It could be that simple, or not. It depends on the receiver (frame), whether it is a ramp cut (and if it is, which style ramp cut the frame employed) or traditional 45 ACP style (the converse is also possible) and also the fit of the slide/barrel to the frame.

Net/net, it depends on the slide/barrel and the frame specifics.

[pdoggeth]

It could be that simple, or not. It depends on the receiver (frame), whether it is a ramp cut (and if it is, which style ramp cut the frame employed) or traditional 45 ACP style (the converse is also possible) and also the fit of the slide/barrel to the frame.

Net/net, it depends on the slide/barrel and the frame specifics.

Is there some online resource that explains what I need to check for in order to do such a thing (my perfunctory google search reveals TMI for me to comprehend at the moment)? After doing the cost estimates I see it ain't exactly cheap (probably will cost the same as the price of a Glock 20!), so before I venture to go through with something like this I want to make sure I'm in compliance.

FWIW, I have a Kimber TLE/RL II, if that helps in easily making some determination if this is possible.

[JTROKS]

When I was loading 10mm equivalent to the old Norma loads I used rifle primers. Just make sure you work up the load.

Check the size of the firing pin hole. A fitted extended firing pin is a good thing to have with hot loads.

[Sailormilan2]

Cool thing you did!

Which leads me to ask you (or anyone with experience), would just getting a 10mm completed slide, 10mm barrel, and 10 mm magazines be sufficient enough to shot 10mm out of a 1911? You also mentioned different mainsprings.

If that's the case and it's so simple, then hell, maybe one day I'll do this myself too!

I used what amounts to a standard 1911 frame, and I didn't want to modify it to use a ramped barrel. Finding a non ramped barrel isn't hard. But, because it isn't ramped, there isn't as much support, so I can't hot rod it as much as some do.
I would recommend starting what a 45 acp 1911 frame, instead of a 9mm or 38 Super. The ramps are often cut differently. The barrel I got was a drop in. You will need to change the ejector, since the 10mm uses the 38 Super style ejector which is wider, taller, and longer. That means you need to widen the slot in the Gov't slide for the wider/taller ejector to work. That isn't hard to do with the right tools.
Some factory guns use a 25# mainspring, but since I want to use my frame for multiple calibers, I stuck with 23#. I used a flat bottom firing pin stop, which takes a bit more force for the slide to move. So, it helps to slow the slide down a bit.
Parts you will need, slide cut for 40S&W/10mm rim, barrel, 20 - 23# recoil spring, 38 Super ejector, 9mm/38 Super slide stop, magazine, 9mm firing pin, 9mm extractor. Some 38 Super mags will handle the 10mm, some won't. MecGars won't, and IIRC MetalForm don't.
In just parts, I have about $250 in this build. Certainly less than $300.

[BoJackUSMC]

Very interesting... you got some skills sir..

[pdoggeth]

I used what amounts to a standard 1911 frame, and I didn't want to modify it to use a ramped barrel. Finding a non ramped barrel isn't hard. But, because it isn't ramped, there isn't as much support, so I can't hot rod it as much as some do.
I would recommend starting what a 45 acp 1911 frame, instead of a 9mm or 38 Super. The ramps are often cut differently. The barrel I got was a drop in. You will need to change the ejector, since the 10mm uses the 38 Super style ejector which is wider, taller, and longer. That means you need to widen the slot in the Gov't slide for the wider/taller ejector to work. That isn't hard to do with the right tools.
Some factory guns use a 25# mainspring, but since I want to use my frame for multiple calibers, I stuck with 23#. I used a flat bottom firing pin stop, which takes a bit more force for the slide to move. So, it helps to slow the slide down a bit.
Parts you will need, slide cut for 40S&W/10mm rim, barrel, 20 - 23# recoil spring, 38 Super ejector, 9mm/38 Super slide stop, magazine, 9mm firing pin, 9mm extractor. Some 38 Super mags will handle the 10mm, some won't. MecGars won't, and IIRC MetalForm don't.
In just parts, I have about $250 in this build. Certainly less than $300.

Not sure I can get those parts for that cheap, unless I want to work on my existing slide (not ready to part with that yet!).

Well, I guess I'll do a little more research into this, whether it's really for me. If not, I could always just go with a 460 rowland conversion, or actually get that silly Glock 20SF.

[Bill Steele]

Is there some online resource that explains what I need to check for in order to do such a thing (my perfunctory google search reveals TMI for me to comprehend at the moment)? After doing the cost estimates I see it ain't exactly cheap (probably will cost the same as the price of a Glock 20!), so before I venture to go through with something like this I want to make sure I'm in compliance.

FWIW, I have a Kimber TLE/RL II, if that helps in easily making some determination if this is possible.

I will start by saying that there is no platform I prefer over the 1911.

In your case, I would recommend if you want to dabble in 10mm, just get a G20SF. It will produce lower felt recoil for similar 10mm loads than a 1911. You can shoot 40S&W out of the stock setup and resale is a pretty painless experience (pretty low risk).

If you really get into 10mm (it is very contagious), consider picking up a Kimber Stainless Target II in 10mm (last time I looked it was still on the roster) and get all the 1911 goodness along with the mighty 10. FYI, I don't recommended shooting 40S&W out of the 1911.

You could follow Sailormilan2's path, but you aren't as knowledgeable about the 1911 platform or 10mm, so if you get stuck, you could be in for some serious frustration.

Good luck.