Tax trime is close enough that I’m thinking about my next project. I love 1911’s but have a hard time carrying them because of an old injury to my strong side hip. For some reason guns that are over 30 ounces or so cause problems after a couple of hours. Anyway, onto my question.
I know steel is best, but, if using a different frame material, what is everyone’s choice? Aluminum? Titanium? Educate me please 
Aluminum will do. Just make sure to replace the recoil spring per manufacturers suggested interval.
I agree on the aluminum. Just make sure you use magazines with plastic/hybrid followers.
I don’t know if Sparks2112 is thinking about a full build or just doing some tweaks to a factory pistol. If it is the latter, the S&W “SC” lightweights have Scandium mixed into the aluminum alloy frames. This may or may not be significant, but given that they are building .357 J-frames out of it, I’d presume that it is.
Rosco
Aluminum framed gun for carry, and a steel gun for practice. this is a time-tested combo. there really is no need for other, more exotic combinations
I have a bad hip too, and oddly enough, gov’t models are more comfortable for me to carry than commanders. somehow the 4" guns poke me in the wrong place/nerve.
An aluminum-framed Commander (i.e., 4" barrel) would probably suit you well.
I don’t know about other 1911 guys but I don’t run +P ammo in mine ( and they are 5" steel ); I suggest something similar with the aluminum frame: say, 200 grain or 185 grain loads if you do a lot of shooting.
I just bought some 230gr +P Hornady Tap FPD for carry but I won’t shoot that ammo much in my Kimber Pro CDP.
For a lightweight 1911 aluminum would be my choice. A well built gun can withstand boatloads of standard velocity ammo so long as you’re mindful about recoil spring changes.
So if aluminum, are Colt aluminum frames anodized? I know Kimber has quit anodizing their frames in favor of KimPro (whatever) and SA are anodized with ramped barrels.
Are you sure about that? I believe the entry models are anodized and the other models like the Tactical, CDP & Super Carry are anodized with Kimpro sprayed over it. Aluminum is soft and the anodizing is used to make it harder.
That is straight from Kimber CS. I called about getting my slide finished to match my frame on my TCII and during the conversation I asked (double checking) to see if the frame was anodized then KimPro over like you said. No go. The frames are 7075 Billet and just KimPro. Not good. The older blueish grey frames on the TC series are anodized. When I asked why he wouldn’t/couldn’t give me an answer on why they stopped. He did say the frames are good for 20,000 of normal pressure loads.
Regardless, this concerns me. I am now questioning my TC.
I’ve never seen an aluminum framed 1911 crack but I have heard of it happening. I like the idea of Smith and Wesson’s scandium/aluminum alloy used on 1911PD’s but I don’t know much about the quality of that particular pistol. I have its precursor, the custom shop’s Custom Pro I, which has been reliable for the few rounds I’ve fed it. I bought it just before I quit carrying 1911’s but if I found myself in the market for a lightweight 1911 I’d give the 1911PD a look.
Aluminum is a broad term, and should basically be looked at in the same way as saying “steel”, lots of different grades/formulas. I’m not sure what series of AL is ideal for a 1911 frame but find it sad that it’s rarely discussed by pros or mentioned in an mfg’s literature.
Given an application, I’ve seen one type of AL wear for twice as long and be much harder to bend than another. There has to be a right mix out there that should be the proverbial CMV of aluminum for 1911/all pistol receivers, in which a quality company would use nothing less.
I don’t know, it might not be necessary to anodize if the gun has a ramped barrel…I’ve noticed that Kimber switched to them for the aluminum frame lineup.
When I inquired about a bobtail conversion for my CDP at the SA Custom Shop they told me that the frame would not have to be re-anodized - just sprayed with armory kote.
Yeah, I guess I should have said. This is going to be for a full build 4.25" gun, non-ramped tube, standard bushing recoil assembly. I’ll look for some aluminum frames if it’s not going to be an issue. My carry load is 230 grain HST +P, think I’d be good to go for 500 - 1000 rounds of that to check functionality once the build is done? Also does anyone know of a company selling aluminum frames fitted to carbon steel slides? The reason I was even considering titanium in the first place is because caspian offers it fitted to one of their slides.
On another side note, would I have to have the frame reanodized after I cut the front strap, add stippling, etc… Or would I. Just need to refinish it? I know what kimber custom shop told one of the responders here, but I don’t know that I trust them completely.
It sounds like this is going to a carry gun, and won’t see the uber high round counts of a competition or training gun. If that is the case any 7075 alloy is going to be a very stout aluminum to build off of.
The anodizing process is used more for its wear resistance than for the integral strength of the gun. It is just the surface that is affected by anodizing. It makes it much harder, and therefore makes for a better bearing surface. I wound worry about checkering the front strap, but I would like anodizing on the slide rails… clear as mud? 
I hope you will post pics of your build up!
The qualities of aluminum are typically optimized for a specific application through alloying. The range of possible combinations of properties is extensive. It is possible to alloy for numerous properties, but some properties are mutually exclusive of other properties.
For a pistol frame, I would be less concerned with hardness - the resistance to deformation - than I would be with toughness - the ability to withstand impact. Toughness often requires some ability to deform elastically.
A 7XXX series aluminum alloy should work very well as a pistol frame.