10mm Lightweight Commander?

[Popoff]

Hello Forum,
First post here. This year just for grins I decided to build a Lightweight Commander in 10mm. I love the feel and balance of the LC, and I've built GM's in 45, and 9mm, and a 9mm race gun too, so why not go to a 10 for my first LC build?  Well, the obvious answer would be that the rip snortin' 10mm will tear the guts out of an aluminum frame in short order, right?  The other obvious answer is the recoil; but I love my 454 Casull, and I've got a little wee pocket 9mm from Diamondback that I shoot okay with a glove, so I don't think I'll worry too much about that just yet; we'll see.

So, to the aluminum frame, I had in mind to use a ramped barrel, and hard anodize the frame against wear.  Then, to avoid recoil stop hole egging and frame battering, I would insert a square bottom firing pin stop (I have a beefy Fusion slide) to increase recoil dwell time alongside increased-strength recoil springs and maybe a heavy hammer spring with a buffer.  The focus of the recoil force would then move to the hammer pin holes, so to avoid them egging I plan to drill them out, tap them, and make-to-measure some steel inserts to act as pin bearings.

I'm using an EGW full length guide rod and a flat-coil recoil spring (22#) and I can experiment with the hammer spring weight, starting with 17# and going up from there. I Really, Really prefer the LC to the CC for carry and braggin' (10mm!) but I guess it's not THAT big a deal if the frame can't take it and I have to go to steel. I'm still buildin' either way. Thanks for your feedback-
Popoff

[The_Shadow]

Popoff, welcome to the forum and the interesting build you have in mind.  Much of the ideas do lend themselves to help with the higher pressure and impulse loads of the 10mm and slide velocity control.  All I can do is wish you all the best for your build...  If you are using regular factory ammo you will likely be just fine or if you handload and tailor the loads to your needs they should provide good service.  Some loads from Underwood, Fenix, Buffalo Bore may reek havoc with the aluminum frame in short order...

Best regards and good luck! 

[sqlbullet]

Welcome to the forum.

I too have thought often about a lightweight commander in 10mm.  I have never headed down that path.

I mirror The Shadow's comments about most factory ammo probably being fine with a lightweight build, excepting those called out that load very much full house 10mm.

Enlarging the slide stop pin holes and installing steel inserts would be a standard engineering solution to the problem of the holes becoming oval.  I agree with your thoughts about a flat bottom firing pin stop and a stronger mainspring.

As I am sure your are aware, there are two schools of thought on recoil springs.  1911Tuner favors no more spring than is needed to reliably chamber a new round.  Bill Wilson favors running the strongest spring that will lock the slide open on an empty magazine.  I would probably fall in the middle with a 18-20 lb recoil spring.

I would also shoot it like the older S&W j-frame 357 magnums.  Run lots of "practice" level ammo at the range, then load up the hot stuff for carry.

[Popoff]

Thanks, Guys, for the welcome and the comments. I would want to shoot a few "real" 10mm from time to time but I get the practice ammo idea. I remember a pretty little SP-101 I once had; I used Wolff springs to lower the DA pull from somewhere near 15# to about 7# and replaced the stock grip with a French one made for InterPol (forgetting the name now, but it was hard rubber and big and bulbous at the end and badly affected the concealment) and that combo was a sweet shooter with full-house 357; never did have to go to low-power reloads or 38 spl with that gun afterwards. In this case, I think I've gotta stick with a high-weight recoil spring and buffer to save frame battering, even with the square base firing pin stop. The mainspring is where I can experiment, both for trigger pull, somewhat, and to be able to reasonably-easily rack the slide, so starting out with 17# and maybe going up seems reasonable. When I say trigger pull, I'm aware that other than squaring and seating (boosting) the sear/hammer engagement the pull weight is mostly a function of the sear spring setting. However, the timing and any bounce of the sear in the hammer hooks (=creep) is strongly affected by the mainspring weight. I intend to post pictures as I go, once the parts trickle in from the Holiday shipping crunch.
Cheers,
Popoff

[Graybeard]

Welcome. Have you considered the Caspian Titanium frame? I'm sure it costs more than a aluminum alloy frame. You could skip the pin bearings which are going to weaken the alloy frame. I think the additional strength and flexibility would be an advantage, too. Add a set of AccuRails to keep the titanium from contacting the steel slide and it should last forever and handle any full power 10mm loads you want to run through it.

Please keep us posted on how this comes along.

[Popoff]

Thanks for the suggestion, Graybeard. The titanium frame is a double stack, and while I want to explore the 2011 world eventually, my focus now is on the commander profile.  Titanium is not out of the question, at $855 it's a bit of a jump from an aluminum frame at $315, but its advantages would be awesome. I've been toying with the idea of the pin bearings, but I'm not totally convinced I'd actually need them.  I may just go ahead with the build and watch for oval pin holes, in which case I can do the drill and tap routine.  This is all new, untested ground for me, so everything is up in the air and it's really exciting.
Cheers,
Popoff

[Popoff]

I should have mentioned that if I do decide to skip the pin bearings, and just go for the build I do need to triangulate the location of the center of the pin hole beforehand. Because if there is the slightest bit of out of round over time and I have a floating center I'll muck up the hammer/sear relationship and be chasing a good trigger pull again forever, unless I just chuck the frame and refit a new one... Maybe I should rethink the 2011 idea and go with a Caspian titanium frame after all; that would be a hoot, but would I still have anything like a Commander?  Anybody tried this?
Popoff

[sqlbullet]

I have a number of double stack 1911's: I build a Para P16-40 to 10mm first, then I picked up a RIA HC in 10mm.  I also have a P12-45 that is part way through a 10mm CCO conversion.

The answer to your question; Kinda.  The grip is a bit bulkier.  But in truth, not that much and I actually find it fits my hand better as I have big hands. The frontstrap is the part of the grip that is very different.  I don't find any difference in concealment between a single and double stack.  If a given holster hides one well, it hides the other well.  (My comparison rig is an SR1911.)  Weight will be a big difference.  The frame itself isn't going to weigh a ton more, but an extra 7-9 rounds of 10mm ammo will make a difference or about 4-5 ounces.

The end result is you will probably feel like you are carrying a standard commander, not a lightweight.  But you will have 15/16/17+1 depending on the magazines you choose. It should point and shoot about the same, but will carry heavier.  Since the usual goal of a LW commander is weight, I think it defeats your purpose.

I will also comment that the built in magwell on that frame is going to negatively affect concealment in a big way.  My RIA HC came with a magwell, which I knew going in.  I assumed I could just drop it off and have a standard 1911A2 frame underneath, but then found that the magwell the ship with requires the frame be cut.  I spent a fair bit of time with a grinder, then files and finally sandpaper reducing and blending the outside of the magwell with the frame/grips.

[Graybeard]

http://www.billscustomautomatics.com/titanium/

These guys must have a source for titanium single stack 1911 frames. There was an article in one of the gun mags awhile ago about another company building custom titanium 1911s, as well. I can't remember the name.

[sqlbullet]

Caspian used to offer them as well:

https://www.caspianarms.com/receiver/recon-receiver-titanium

Makes me wonder if some custom shops just bought up all of caspian's inventory when they DC'd it.

I would also comment...Aluminum is about 1/3 as heavy by volume as steel.  So if no dimensional changes are needed with aluminum, it will weigh about 1/3 the same part in steel.  Titanium is no where near that light.  It is about 2X aluminum, or about 2/3 of steel.  You are not going to get the same weight savings.

Titanium is also stronger than aluminum, so fully engineered a part made from aluminum or from titanium will be about half the weight of as fully engineered steel part.  But this assumes you are re-engineering the part for each metal, which is not the case where.

[Graybeard]

I agree Sqlbullet. I think the real advantage would be the titanium would be far less prone to cracking.

[Popoff]

Okay, Guys,
The message I get is that apart from the strength of titanium, the lightness and feel is somewhat compromised, as well as the handling by the double-stack frame, not to mention concealability and so on.
I'll stick with pre-installed sheet steel bearings that match the aluminum frame thickness. That way we keep the cost down (except for the handwork, which is really pretty easy) and it stays within most folks' realm of possibility. I can post pictures/make a video. On reflection, I just don't think an aluminum frame can stand it unless I baby it, and that defeats the purpose. BTW, this gun is supposed to seem really evil; I have a beefy Fusion slide in stainless that in black oxide will look like a Soviet limo. My barrel will be a Fusion UltraMatch with an extension for the suppressor sticking out the front, and my slide will be anodized dull black with blued bits and pieces.  I think my grips will be something like the delicate white, lightly stained orange-pink of giraffe bone that Longhorn Custom Grips makes from time to time, but maybe I'll just decide to go all Alien with something in a textured, sculpted black G4. Then I want to go shoot Hell-fire loads out of it at the range, and it will be a 10mm Lightweght Commander! How could it possibly get cooler than that?
Many, many thanks for your comments and wisdom. Now to let the parts roll in.
Cheers,
Popoff