10mm vs 45acp 1911 magazines, differences...

[Koda94]

What are the differences between a 1911 magazine for a 10mm and a 1911 mag for a 45acp?

I always figured they were not interchangeable but then I was thinking that since the 1911 reciever is the same regardless of caliber then why should the magazine be different, so today I brought along a cheap 8rd 45acp (CMC) mag and ran it through a Colt Delta 3 times and it ran flawless all 8 rounds each mag.

Curious if anyone else does this, is there any harm in this or reliability issues?

 

[jmr40]

Never tried it, but you may find that it will work, at least with some mags and some guns. I wouldn't trust it for SD, but might as range mags. In know that during the AWB days you could buy 10 round magazines in 40 S&W that would hold 14 rounds of 9mm. In at least some guns they would feed and function just fine. I tried it with Beretta and Glock.

 

[Will-j]

10mm/.45 mags

KODA..... Not a bit of difference except the distance between the feed lips.
.45's too wide for complete retention of 10mm cases after a whole lotta rounds through them, and 10mm's too narrow to feed and load the 45s.
On a whim about 3 yrs. ago, I narrowed the lips on a .45 mag to 10mm specs with LIGHT taps, and fired a full mag 4-5 times w/o fail. Works in a pinch. Just use a plastic- faced hammer to bend the lips to keep from deforming them too badly, and fill the mags with empty 10mm rounds before reforming, GOOD LUCK.
WILL

 

[Koda94]

KODA..... Not a bit of difference except the distance between the feed lips.
.45's too wide for complete retention of 10mm cases after a whole lotta rounds through them

Good to know there could be a reliability issue. I might have had a thought of saving money but not at the cost of reliability from modifying. I might mark one 45 mag for range use and test over time but will just buy more dedicated 10mm mags if needed. Good to know though the differences and what one could use or easily modify in a pinch... thanks for the reply.

 

[RickB]

that since the 1911 reciever is the same regardless of caliber

They're not. The frame feedramp is a different height and depth for different calibers.
I have hand-cycled 10mm rounds through a .45 mag, and it appeared to work well, but I have a supply of 10mm mags, so never bothered to try it at the range.
I have one 9-round 10mm mag which won't lock in the gun when fully loaded, but an extended-tube 8-round .45 mag will lock with nine rounds of 10mm on board.
I knew guys who tried to get 10rd .45 mags running reliably in single-stack .40s, but with limited success.