New 9mm top end for 1911


Harold Mayo
January 8, 2003, 08:58 PM
I have a custom 1911 that was built from the ground up. It is chambered, as it should be, in .45 ACP. I love it, HOWEVER...

I am hankering for another custom gun but don't really want to go all-out. I am thinking that I should have the same gunsmith build a 9mm top end for the pistol.

This would involve a new slide, barrel, sights, firing pin, firing pin spring, recoil spring, recoil spring guide, recoil spring plug, extractor and firing pin retaining plate. Anything else that I'm missing? I would imagine the ejector would have to be replaced, as well.

Anyone done this? I have seen on GunsAmerica a Colt Commander that Ted Yost supposedly did while he was still at Gunsite that had both a 9mm and a .45 ACP top end. I was actually offered it in trade for something at one point but I turned it down largely due to the front slide serrations.

Would a 9mm top end work with the frame set up for .45 ACP? I am most concerned about the feed ramp (well, the ejector, too).

Anyone else done this? I am thinking that a 9mm top end to a 5" 1911 would give me what amounts to a heavy barrel as well as having a round that recoils less. With the two combined, there shouldn't be much muzzle rise at all. It should be a quick-shooting and accurate gun.

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January 8, 2003, 09:38 PM
Sounds like a nice project.

there shouldn't be much muzzle rise at all

You have problems with this in .45? A strong grip with locked wrists, arms, etc. might help you out in this department.

If you don't mind me asking, how much do you weigh and how tall are you?

Harold Mayo
January 8, 2003, 09:52 PM
I don't have a "problem" with recoil at all, but it exists, nevertheless. I have seen a guy with a high-capacity 1911 in 9mm shoot and there is NO indication of the muzzle moving upward at all. The only thing is the slide moving backwards. I haven't shot a 9mm 1911, but he (and another guy that has one) claim that they don't lose the sight picture at all.

I'm 6'1" and 250# with a lot of upper body strength, so recoil management isn't in question...I just want to mess with yet another gimmicky gun thing and see how it works.

January 8, 2003, 10:31 PM
I have done this both ways: 9mm to .45 and the reverse.
My first 1911 I purchased was a Colt series 70 in 9mm. I got it for thereasons you stated - low recoil (and cheaper factory ammo). I really like this gun and use it very often - even after I have purchased many,many more that I can choose from.

A few years ago I obtained the parts to allow conversion of this 9mm gun to .45ACP and it works very well. I think you hit all the key parts except for a new slide stop. Yes, you do need an different ejector. I also suggest a full length guide rod as it keeps all the parts for your top-end together (except for the ejector and slide stop). This makes the conversion very quick and easy.

To remove the ejector you will need to remove a pin that holds it into the frame. I actually leave this pin out since the slide holds the ejector in place when the gun is assembled. It has not caused a problem after several thousand rounds fired and it greatly simplifies the conversion.

I recently purchased a SA 1911 9mm converion kit and have been doing the reverse conversion to one of my .45 1911's. So far it works OK but the SA parts a way too loose to be very accurate.

Good luck!

January 9, 2003, 12:21 PM
I too thought the 9mm would recoil less than the 45 in a similar pistol -- Until I got my Combat Commander 9mm. Then I discovered that they kick about the same to my thinking. :confused:

January 9, 2003, 12:27 PM
Actually I also found the recoil to be 'different' and not really lower.
The 9mm tends to have a 'snappy', twisting recoil feel while the .45 is a slower 'push' recoil.

However, 9mm in a heavy, full sized 1911 will be reduced compared to a lighter gun.

May 8, 2008, 10:40 AM
I too am toying with the idea of setting up a 9mm slide for my 1911. I have a Kimber 22 conversion for it now and I love that, could not ask for more.
I built my own custom 45 and I found out that I could have just bought a Kimber for about the same price or less. Since my gun looks a lot like a Kimber now, I question my wisdom to do all that work again.
Is there a company that you can just buy a complete 9mm slide set up or do you have to buy all the parts and do it your self?
The reason I want a 9mm conversion is in part due to the low cost of ammo. The other part is, when I shoot IDPA, my Browning HP feels different than my 1911 and it is hard to get it lined up on target as fast. I am so used to the 1911 design that I want to shoot it in 9mm.
Any information, thoughts or web sites would be much appreciated.

May 8, 2008, 10:58 AM
I have done this both ways, i.e. .45 to 9, 9 to 45. The ejector is the only frame mod other than a new slide stop.

The only advantage in this is:

1) You like to tinker
2) You don't reload and want to shoot cheaper 9mm ammo
3) You can get the parts at a reasonable price

The recoil is subjective. The 9mm is a like a "sharp" semi-jolt, the 45 is like a mild, slow "push". It's fun to do if you're a do-it-yourselfer.

The main drawback is the ejector removal, it's not practical to do this often, but with the right punch, it's relatively easy to do.

What someone needs to do is design an ejector with a built-in adjustable "set screw" to allow for adjustment for either cartridge. This would make the conversion practical and very easy.

May 8, 2008, 12:12 PM
You've identified the main issue of the feed ramp. They are different, but they sometimes will feed fine with either caliber. Luck? Who knows. The ejector issue is primarily with the Gov't configuration as the the clearance cut in the slide is caliber specific. Not so on Commander length guns. Years ago, in a land before time when dinosaurs roamed the earth, "Commander" ejectors were sold as being an improvement for the Gov't guns. What they were really pushing was an extended ejector. All this to say that ejectors are caliber specific, too, but you might get away using the same one on a Commander length gun. I've considered the possibility of cutting the ejector clearance slot on Gov't length slides to match a Commander for similar reasons.

Jim Watson
May 8, 2008, 12:54 PM
I think the territory has been covered, but I will add...

I wanted a lightweight full size 9mm G.M., but nobody made one at the time. So I bought a Springfield Loaded 9mm and a Bi-Tone Lightweight .45 and had FLG swap the uppers. He did a LOT of work on the integral ramps to get them to feed the opposite caliber. I don't know if that would apply to a real 1911 with frame ramp.

A friend put a .38 Super upper on a .45 Gold Cup lower. It shoots fine. He wanted the cheap ammo so he added a 9mm barrel. It has never been reliable enough with the 9mm barrel. I don't know if he got caught by feed ramp differences that finally showed up with the shorter round, or if he did not get the extractor right for a rimless case, or if it is a magazine fault. But it was not a successful conversion.

I have heard of milling the .45 slide to pass a .38 Super ejector. That is the way Commanders are built and the reason it is simpler to do a caliber conversion on one of them.

I bet that if the .45 ramp gave trouble with 9mms, a patient gunsmith could put in an EGW insert and cut it back to a compromise shape that would feed both. But patience doesn't come cheap.

February 3, 2010, 10:29 PM
oh ... I tripped into this old thread.

So ... how did the conversion go?

I would not mind trying it myself.

Harold Mayo
February 5, 2010, 01:39 PM
Never did it. I'd rather buy a complete 9mm 1911 than just get a 9mm top end on my Michiguns 1911, anyway.

navyretired 1
February 5, 2010, 02:17 PM
The ejector can be left in place if you use a 9mm ejector fitted to eject both cartridges. The real problem is the feed ramp, the 45 ramped frame is wider than 9mm needs to be and CAN but doesn't always causes problems. It sure looks bad though. If you just want a 9mm government model buy a virgin 9mm frame and build one.
The real option would be two ramped barrels fitted to same frame, much easier and more dependable.

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