[GatlinCat]

Is it possible to convert a colt .45 1911 to a .40 S&W?

[matt g]

Quite a few companies build 1911s in .40 S&W these days. Check with Wilson Combat to see if you can get the required parts. I'd imagine it would just require a barrel swap and maybe a new recoil spring.

[hideit]

colt used to sell a 10mm in the 1911 frame
but why would you want to do this
for a $1000 - 1500 job you could 2-4 glocks that hold a lot more ammo in the clip !!

[matt g]

A quick Google search turned up the fact that several companies make drop in .40 S&W barrels for 1911s. The best would probably be Bar-Sto. http://www.barsto.com/category_main.cfm?ID=COLT

You may also need a new extractor. I'm curious as to why you'd want to convert to .40 S&W. It tends to have a sharper recoil than the .45 ACP and isn't much more controllable. A little practice with the .45 ACP will help you with controlling recoil and getting your front site back down a little more quickly.

[Dgunsmith]

You will need a complete replacement upper...

slide, barrel....and with the 40 upper, you could swap into a 10mm barrel..they share the same breach face 40S&W and 10mm.

Sharing a common frame with different slides is cool !

You will need 40S&W magazines as well. Available from Metalform who makes the mags for Colt

[Chuck]

Originally Posted by GatlinCat

Is it possible to convert a colt .45 1911 to a .40 S&W?

Why would you even want to???

[Gunnutz13]

Very possible...but...why would ya ??!!

The .40S&W is only a necked down and made wimpy 10mm

The 45acp has better ballistics and is easier to control on the follow-up shot

And for the money to convert...you could buy a brand new forty, and still keep the 1911 platform

Just my 2 cents...

[jeepcreep927]

40 s&w is not a "necked down" 10mm. The case is shorter but the bullet diameter is the same. Bullet weights for standard loads are too different, as is velocity. There individual effectiveness is based on two different theories: heavy and slow vs. lighter and faster. As it relates to guns themselves, magazine capacity and physical size are considerations. One fills a role just as well as the other, based on preference for a certain caliber more than anything. I would think you would have to shoot several people with both calibers then analyze the shootings. There are numerous reports written based on exactly this standard. I think if you study them there wouldn't be a huge difference in effectiveness, at least not enough to discredit one or the other.

[Pat-inCO]

Originally Posted by Gunnutz13

The .40S&W is only a necked down and made wimpy 10mm

As noted above, not true. The 40S&W is a small primer (large for 10mm) and a case that is .142 shorter. No other difference.

Originally Posted by Gunnutz13

The 45acp has better ballistics and is easier to control on the follow-up shot.

Also not true. The 40S&W is a much flatter shooting cal.

Originally Posted by Gunnutz13

And for the money to convert...you could buy a brand new forty, and still keep the 1911 platform

BINGO!

[Dick]

Colt made a 1911 in 40 S&W years ago for about 9 months. One of the models was number 08040 with a blue upper and stainless steel lower. Another one was model number 01040 which was all stainless steel.