Caliber conversion kits on 1911. Limitations?

[Nepherael]

This could be a simply answered question. I've seen it asked a few times with research but the answers didn't help me understand the "why?" of it.

So I have a .45 1911. I can buy a 22 LR conversion kit for it. I believe that's just a barrel and slide and maybe some specific magazines.

Why is it possible to convert to .22 but not another caliber like 9mm? I understand there are specific limitations like having modified mags but I still haven't been able to grasp why I could convert to such a low caliber and not somewhere in between.

Appreciate the enlightenment.

 

[eldirector]

A quick google turns up options for 9mm, 40 S&W, 10mm, Super .45, and probably some others.

 

[Nepherael]

A quick google turns up options for 9mm, 40 S&W, 10mm, Super .45, and probably some others.

Yeah there's tons out there but most are limited in such a way that you can't find a mag to put into a .45 that holds 9mm. At least that's what I'm reading. The conversion kits (outside of the 22) seem to just have the upper assembly but no mags. Maybe I'm missing something. When I Google it I find some kits but I also run across a bunch of forum posts that say it isn't possible to go from .45 to 9mm. I could be seeing posts from very uninformed individuals though

I'll check further for specific mags that fit 9mm ammo in a .45 frame.

 

[eldirector]

Brownell's carries 1911 magazines for 9mm, 10mm, and 38 Super.

Looks like the conversion kits don't normally come with the magazine. There are factory 1911's in the above calibers (and more), so the mags are available.

 

[Nepherael]

Brownell's carries 1911 magazines for 9mm, 10mm, and 38 Super.

Looks like the conversion kits don't normally come with the magazine. There are factory 1911's in the above calibers (and more), so the mags are available.

So I must be taking the posts I'm reading as gospel. I was under the impression that the frames were different so I couldn't just buy a 9mm mag for a 1911. Based on what I read I thought it would require a special "9mm magazine for .45 acp 1911".

If that's not the case then there's a lot of false info out there saying that the feed ramp needs modification, the mags won't fit, and it's just generally not possible to convert a .45 to multiple calibers.

 

[obijohn]

The issue is the breech face of the slide and ejector geometry. Frame can be the same.

So I must be taking the posts I'm reading as gospel. I was under the impression that the frames were different so I couldn't just buy a 9mm mag for a 1911. Based on what I read I thought it would require a special "9mm magazine for .45 acp 1911".

If that's not the case then there's a lot of false info out there saying that the feed ramp needs modification, the mags won't fit, and it's just generally not possible to convert a .45 to multiple calibers.

 

[Dean C.]

Depends on how nice the 1911 is, none of my 1911s would like a "drop in" kit at all but they are all semi-custom and fit tighter than drums.

I may be biased but the words 1911 and drop in just do not go together imho

 

[churchmouse]

Depends on how nice the 1911 is, none of my 1911s would like a "drop in" kit at all but they are all semi-custom and fit tighter than drums.

I may be biased but the words 1911 and drop in just do not go together imho

Ding ding ding...We have a winner.

 

[Ggreen]

I've put my 9mm ro slide on a taurus pt1911 45 frame with zero issues. It wasn't as tight but it worked. There are some very serious 1911_22 race guns. If you're on facespace look up rimfire race guns group. These are all built off of standard 1911 frames. If you just want a plinking conversion, you can buy the drop in slides and will likely run as good as a non custom 1911 can.

When it comes to 1911s they are just finicky. You either get one smithed to run tight flat and fast, buy a quality brand (that still benefit from a visit to the backroom of a body's hop in Avon), or they build them loose enough to where they just run, like the taurus freak pistol. A drop in conversion with no fitting will be somewhere in the middle road of reliability.

There are non standard 1911s in other calibers, browning gsg etc... That are dedicated to their caliber and are not one of the standard frame sizes.

 

[Nepherael]

Gotcha so basically they really are interchangeable but there could be issues with the breach and feed ramp depending on the conversion.

I do have a follow-up question to this then. I have a Colt 1911 competition series in .45. It has a beautiful fit. As far as I can tell (and I'm not that experienced) there's no slop in the frame to slide fit nor the barrel lockup. That being said, if I purchase conversions for this 1911 is it possible to cause issues with the fit of my current setup? As in, should I be concerned that when I switch back to the stock build could I create slop in the fit? It doesn't seem like I would create extra wear and cause problems but I just wanted some input from some more experienced guys out there.

I plan to buy many aftermarket slides because I customize them and if it may cause fitting issues with my stock parts then I may have to invest in a cheapo 1911 just to get the frame from it.

 

[Ggreen]

Gotcha so basically they really are interchangeable but there could be issues with the breach and feed ramp depending on the conversion.

I do have a follow-up question to this then. I have a Colt 1911 competition series in .45. It has a beautiful fit. As far as I can tell (and I'm not that experienced) there's no slop in the frame to slide fit nor the barrel lockup. That being said, if I purchase conversions for this 1911 is it possible to cause issues with the fit of my current setup? As in, should I be concerned that when I switch back to the stock build could I create slop in the fit? It doesn't seem like I would create extra wear and cause problems but I just wanted some input from some more experienced guys out there.

I plan to buy many aftermarket slides because I customize them and if it may cause fitting issues with my stock parts then I may have to invest in a cheapo 1911 just to get the frame from it.

Not really. The breach and feed will be on the conversion slide. The only issue you should /could have is the way the slide fits your frame.

The only issue it could cause to your current set up is if the conversion damages the frame, I've never seen this from a quality conversion. Most bare slides are meant to be gunsmith fitted and will cause problems

If you like your 1911, buy a cheap one to play with different slides. To be honest you really need a mill to actually fit a slide to a frame, or a lot of time with files and a vise to correctly fit a slide. 1911's are not glocks or ar15s, there is a reason you can't build a proper 80%1911 without a milling machine but you can build an 80 glock or AR with a dremel. Running sloppy slides can wear your frame and will give you first hand experience why 1911s have a bad reputation for reliability.

 

[Good on paper]

I would suggest you look at the economics of it as well.
Marvel brand .22 1911 conversions are considered a good quality 22 conversion. The most basic one retails for $280-300, mags are $25. So if you want the top end and 5 mags for steel challenge you’re looking at $400+ for a .22 that PROBABLY will run pretty well. You could easily get a used 22/45 Target or Lite or a S&W victory and still have money left over for some go fast race parts.
I didn’t look at the numbers for a 9mm but I would assume it’s a similar story.

 

[Hookeye]

Some folks like the idea of a "kit".......

kinda like a TC encore/contender w multiple bbls.

Maybe a 1911 owner just wants an "extra" slide/cartridge.

I like 1911's just fine, but am not crazy about them.
Would not get a conversion kit just to make it "more".

Only real conversion kit I'd consider would be an old Kart .22rf , as they shot pretty darn good.
Of course, no longer made and I have zero idea what the kits go for today.
My guess is not cheap.

I'd stick it on a good frame and leave it.....no switching back and forth.