Colt 9mm conversion kits - do they work?

[Paradiddle]

I have a line on a series 70 Colt 9mm conversion kit. The owner (and Colt when they made it) claims you can put it on a Colt 45 acp frame and it will run. Now I read all day that the feed ramp angle is different and that you can't put a 9mm slide on a 45 frame and make it work. How did Colt do it - or did they?

Do they work? They didn't sell them for long - is that because no on really wanted a 9mm 1911 or because they just don't work. The conversion isn't cheap so I'd love to hear from people on whether or not they are worth it.

It would be a great solution for me so I wouldn't have to buy another gun as I can't get the gun I want in the state I'm in.

Thanks,

Jeff

[Paradiddle]

I'm talking about one like this

FACTORY COLT SERIES/80 9MM CONVERSION KIT Colt Automatic Pistols (1911 & Var) for sale, gun classifieds or gun auction from DJSTRAP. Buy or bid on this FACTORY COLT SERIES/80 9MM CONVERSION KIT in the category Colt Automatic Pistols (1911 & Var) on G

[rock185]

I bought one of the Series '80 kits and used it on a couple of my Colt .45ACP frames. Same as Series '70 kit except mine had the firing pin safety. The .45ACP feed ramp is indeed different than the one used for .38 Super and 9MMs, at least in Colts. The .45 feed ramp in the frame is machined further forward, causing the bottom rear of the 9MM barrel to slightly overhang the barrel ramp. The conversion kit chamber mouth, at least on my kit, was cut for the .38 Super / 9MM frame ramp. It took a little modification of the barrel throat ramp area to get my kit to work at all. It worked well with 9MM ball ammo but was never 100% reliable with hollow point ammo. I would use the metalform "front ramp" type magazine if I were to ever acquire another of these kits. I think it would have solved some of the reliability problems I experienced with the kit. They are a quality product, and if they were still in production at a reasoinable price, I'd buy another. They are much less common than the .22 kits and not cheap, but they are a workable solution to having a different caliber on your frame. May I suggest that you have any barrel ramp modification of the kit done by a reputable gunsmith, if you are not knowledgeable about what I have described. It is Real easy to screw it up and easy to remove metal but Real hard to put it back... ymmv

[Paradiddle]

So the feasibility of switching a complete slide between 9mm and 45acp even with the "official Colt conversion" doesn't appear to be a reality.

I don't want to modify my receiver.

Jeff

[ace]

i'm not aware that there ever was an 'official" colt 70series 9mm conversion unit.
to the best of my knowledge they only made an 80series 9mm conversion unit.

[Paradiddle]

i'm not aware that there ever was an 'official" colt 70series 9mm conversion unit.
to the best of my knowledge they only made an 80series 9mm conversion unit.

Hmmm. Maybe the guy has it backwards. In any event - did they work?

[rock185]

Actually it is feasible, and you do not modify the frame / receiver. It is all done on the feed ramp / chamber entry area of the conversion barrel itself. Any grinding on the receiver ramp area would only make things worse, and also ruin the receiver for use with the original .45ACP top end. Having learned more about the O-frame pistols since owning the kit, Colt armorers schools, etc., I believe I could get a kit to work 100% with any quality 9MM ammo now. BTW, I never saw, or heard of, a Series '70 kit either. But, I am not an expert in conversion kit variations, so I don't know if such exists.

[JudgeColt]

I am not an expert on Conversion Units either, but they are one of my areas of special interest so maybe I can add some verified information

I have a New-In-The-Box Colt Model O3009 9mm Conversion Unit I bought new in about 1983. As I recall the story at the time, the commercial 9mm Conversion Unit was an offshoot of a Colt proposal to convert military Models of 1911A1 still in inventory to 9mm to satisfy the military's desire to convert to the NATO-standard 9mm cartridge. The 1980s were also the high point of the 9mm craze and the 9mm Conversion Unit gave Colt something to offer owners of .45ACP Government Models so they could shoot 9mm ammunition if desired.

I am puzzled by the posts that say the Conversion Unit barrel throat will not line up with the .45ACP frame feed ramp. Why would Colt sell a Conversion Unit that required modifying the frame of the pistol being converted, thereby ruining the frame for use again as a .45ACP? The barrel throat on my 9mm Conversion Unit lines up perfectly with a .45ACP frame feed ramp.

Perhaps those making that statement have tried a regular 9mm Government Model barrel, from a Government Model originally chambered in 9mm, on a .45ACP frame and found the mismatch stated. Since I do not have a 9mm Model O, I cannot say for sure whether the frame feed ramp is in fact different in a .45ACP pistol and a 9mm pistol. Apparently, that is the allegation. Someone with a Government Model in both 9mm and .45ACP will have to compare and report.

In closing, I find it interesting that the 9mm Conversion Unit is a deluxe item, having the beautiful Gold Cup-style serrated flat top rib. It also has a collet bushing. The slide is marked "Series 80" since it has the firing pin safety. The manual on mine is copyrighted in 1983. A manual for the Series 80 pistols is also included in the box. The box is a wood-grain Styrofoam insert box of the large size, big enough to hold an 8-inch Python or 7.5-inch Single Action Army. The end label is dull dirty gold with the identification hand-written in black fine marker.

Without checking old records, I cannot remember exactly when I bought it, but it was probably in 1983 since I bought the first one I ever saw offered by a distributor. I never planned to use the Unit, but, being a fan of the various Colt Conversion Units, I wanted one to add to my collection of Conversion Units. I suspect the 9mm Conversion Units are scarce, if not downright rare.

There are NO other Conversion Units in 9mm prior the the O3009 Units, meaning there were none without the firing pin safety. I do not use the term "Series 70" since that is a term of art to be applied only to a Model O pistol with the collet bushing and a marking of "Series 70" on the slide. The Commander and Combat Commander and .22 Conversion Units were never marked "Series 70" since they do not have the collet bushing that is the distinguishing feature of a "Series 70" pistol.

[brokedave]

Paradiddle, do you mind telling what the asking price was?
I saw one at a local gunshow here a couple of weeks ago but didnt pay much attention to it as its not something I'm usually interesed in. However, in light of JudgeColts comments on its collectabillity I'm interested now. I Have found the dealers number and will call in the day or two. From memory it was around the $400 mark.

[retiredgunsmith]

I was COLT warranty repairman and had a few come because the customers had problems.

The problems were because they tried to use a barrel not original to the unit.

The barrel from the unit had a different contour that that on the 9MM Government and Commander model pistols
Robert