Today a friend brought his Springfield Armory 10mm M1911 clone by so I could put it back together for him (he is not much of a gun guy and didn't know how). He mentioned that he wanted a spare magazine for it, and I wondered if a .45 ACP magazine would work. I have enough of those laying around that I could give him one. It looks like 10mm cartridges go into a .45 magazine OK, and it fits into his 10mm pistol. I loaded a .45 magazine with 10mm, and they hand-cycled through his pistol OK. Of course no way to actually testfire to see how well it works for actual shooting. Has anyone tried this and does it work? I own nothing in 10mm so I have not tried this previously myself.

Worth a try, I doubt the magazine will hold the 10mm. Just spit them out

I don't see why not. We discovered, back during the ban, then a 10 round magazine for a Beretta 96 40 caliber would hold 12 rounds of 9 mm, and worked just fine in a Beretta 92.



The difference in diameter of a 9 mm and a 40 is about .05, and the difference in diameter between a 10 mm and a 45 is about .05.



Ortgies made a pocket pistol in both 32 and 380, and used the exact same magazine for both of them. The difference between a 32 and a 380 is about .04, and that worked.

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I always take precautions

Be skeptical, 1911 mag won't allow the interchanging of 10mm and 45ACP, But usually will allow length variations like 40 in a 10 and 9mm in a 38 Super mag.

Ivan

Agreed...40 S&W and 10mm are very close, but not .45 ACP.

Using 10mm fed from a 45Auto magazine can work briefly for range use, but would not be ideal.
You are going to be ~0.03" too wide on the feedlips, so you will likely have inertial feeding jams and a presentation that is way too angular/high.

A friend and I were at the range last week. He had a 10 mm he wanted to try out. Lo and behold, he forgot his 10 mm magazines but he had a 45 magazine with him. So we gave it a try. The longer, heavier rounds of 180 and 200 gr fed fine. He did have some problems with 165 gr bullets that had tendency to pop out. I was surprised that any of them worked. Not the best way to go, but it showed me that this could work in a pinch.

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Everybody could shoot

I'd say give it a try and see what happens.

I'm guessing if I go through all my 1911 magazines and measured them, I would find at least one 10mm one that would be essentially identical to a 45ACP, with both being on the fringe for their respective groups.

Of course I would also guess that being on the extreme end on the measurements, both of them would be among the less reliable ones that only work well with a specific bullet type.

If the friend needed help putting this 10mm 1911 back together (who took it apart?) what is he doing with a 10mm to begin with...?

Cheers!

P.S. I would opine it might be a good idea to point out to him that buying the correct parts (i.e., magazine, ammunition, barrel, etc) for ANY firearm's design and caliber is usually a splendid way to avoid a potentially very unpleasant occurance...

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Sit Reloader Sentiret

All of us are speculating when you have experience!

As I said, he is not a gun guy. He bought it used several years ago and has fired it only a few times. One of his sons took it apart to clean it and did not know how to reassemble it, so he brought it to me as parts in a plastic bag. It was missing the recoil spring rod and spring cap, but I had several of those and put mine in. The barrel bushing was extremely tight in the slide, nearly impossible to move without a bushing wrench. I have never needed a bushing wrench and do not have one, so I had to carefully use pliers to turn it. Anyway, I got it put back together for him, the only problem being the tight bushing.

10mm Auto in a 45 ACP mag is far from ideal, but depending upon the magazine, it might work ok. I certainly would not rely upon such a combination for anything beyond using it as a range toy or testing purposes.

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VCDL, GOA, NRA

Browsing through the internet, most report 10mm ammunition works just fine in .45 ACP magazines. Others launch into discussions about which .45 magazine brands work better than others. One interesting posting said the feed lip dimensional tolerances of .45 and 10mm magazines overlap, so there is no significant differences in that regard. I suppose the message is simply that if your .45 magazines feed and function reliably in your 10mm pistol, then use them. If they don't, then don't. I have no 10mm pistols so I have no way to test the idea, nor do I really have any reason to care.

Have to look through my safes to verify this - I'll get around to it eventually, but I feel I ought to share this. Two or three years ago I got a nice 10mm M1911 from Rock Island. It came with two magazines, both still in plastic wrappers. Both the wrappers and the mags were marked 45 ACP. There was a little printed note included, saying I shouldn't worry, that these mags had been tested by RIA in their 10mms, and they guaranteed they would work fine. They did, and they have for years now. Sceptical to a fault, the day I unpacked the 10mm, I ordered two 10mm mags from Wilson Combat. They work fine as well and are used as the no1 and no2 mag.

My 1st 10 mm was a RIA, came with a 45 ACP magazine that functioned just fine. Shot maybe 100 rounds with the 45 ACP magazine before buying some 10 mm magazines. IMHO for a range magazine 45 ACP magazines are ok Provided one Tests them. For CCW get 10 mm magazines.

My Kimber Camp Guard does fine with 45acp
magazines with the exception of the Wilson 47D's.
They release the rounds a little to soon and tend
to jam.

Plain Jane USGI mags run the best of the 45 mags
in this gun. I "think" it's because the feed lips are
long in them and allow the 10mm's more alignment
time.

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never get out of the boat

It seems to work for some. I tried Colt 45 magazines in my 10mm Kimber and it didn’t work at all.

Dan

I have a Ruger SR1911 in 10 MM. Tried 10MM's in .my Colt .45 ACP magazines and they worked fine. No FTF, no rounds popping out of the magazines, all worked fine. Maybe if you get ahold of some mags that need tweaking you may have troubles, but with properly fitted mags it should work. .40 Cal's fed fine too. I am building up a Colt frame with three slides in six different calibers. Just a play project to keep me occupied. In one slide I am running .38 Super, .38 Special, 9MM, .40 Cal. In another I am using just a .45 ACP and in the third I am using a Colt Conversion Unit. Have used the same mag for the .38 Super, 9MM and .40 Cal.

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USMC 69-93 Combat Pistol Inst.

My finding is that feeding 9mm from .38 Super magazines is not 100% reliable. And of course, .38 Super won't work in 9mm magazines. At least that is the case for my magazines. I have three each 9mm and .38 Super mags for my Colt.

I have three or more for each caliber. All seem to interchange well. The only ones that won't are the .38 Special mags and the .22 mags. The only one that I have a lot of mags for is my .45 ACP mags. When I wore it as a duty gun I carried seven mags with me, one in the chamber and one in th pistol and six in pouches for a total of 50 rounds.

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USMC 69-93 Combat Pistol Inst.