.38 Super to .380 ACP. it is possible?
I have a Colt Goverment Series 70
If you can find a barrel in .380 ACP for the 1911, it could be done. But the only one who makes such a beast (1911 in .380 ACP) is Imbel, and it's not imported in US.
Why would you want a full size pistol chambered in a pocket pistol caliber? Also, short rounds like 9mm sometimes don't feed well in the 1911 design, the .380 is even shorter.
This .380 do really not work good in a 1911?
I do not see why not, at least Imbel makes one (Hawkmoon can give you more details on that, if you can catch him around).
As far as I know, the only company offering a 1911 chambered for .380 ACP is Imbel in Brazil ... and they don't export it. It's actually a bit of a "mutt" of a 1911. It's a Commander-size pistol, but the barrel isn't linked. The barrel lug is deeper than on a 1911 barrel and the slide stop pin goes directly through a hole in the lug. Since the barrel is fixed to the frame, obviously the slide can't lock to the barrel, so there are no locking lugs on the top of the barrel or underside of the slide.
Which makes the operation straight blow-back, which is unlike a standard 1911.
I made a valient effort to bring one into the U.S. earlier this year, and I was shot down by the BATFE. I haven't decided yet whether or not to try again. If I do, I will need to approach it differently on the Brazil end. Imbel actually reserved a pistol for me and held it for over three months, because the BATFE requires the serial number on an individual import permit. Naturally, the BATFE waited the full three months before denying my application, at which point Imbel decided they couldn't hold the gun any longer. And who can blame them? And at the same time, I didn't feel I could risk actually buying it on speculation, although if I decide to try again that's probably what I'll be forced to do.
IMHO it's an open question whether or not the .380 ACP round has enough moxie to unlink the barrel as well as push the slide back. There has to be a reason why Imbel built theirs as a direct blowback pistol. So it may be more complicated than just reaming a chamber for a .380 cartridge in a 9mm or .38 Super barrel blank.
I always refer to Pistolsmithing, by George C Nonte, Jr., chapter 26 for conversions. I doubt there is any cartridge that will fit in the magazine well, and will get spit out from the ejection port, that can't be used in a 1911. The proper recoil spring tension is the trick.
Actually you have to use a 9mm slide, not a 38 super slide. The rim of a 380 is too small to extract 100% in a true 38 Super slide. There would be other issues but they are fairly straight forward to deal with. You might have to reduce the weight of the slide and the barrel, and play with recoil spring rates but all of these things are fairly common on USPSA/IPSC guns so its nothing new.
Also long as you are using a .355 bullet any 9mm barrel could be used, you would just have to have the chamber cut for a 380 instead of a 9mm.
There might be issues with feeding from the magazine but most would probably be eliminated by using a spacer in the back of the magazine. Might have to use a ramped barrel and move the feed ramp back a little.
Nothing that couldn't be done, but it might be a little on the pricey side because of all the hand work involved to get it to run 100%.
I don't see any advantage to doing this in the U.S. 9mm ammo is less expensive than .380 ACP ammo, and there are slides and barrels available for 9mm that can esily be used to convert from .38 Super.
The only reason the Imbel Pistola .380 exists in Brazil is that both the .45 ACP and the 9mm round are considered to be "military" calibers, and Brazilian law doesn't allow civilians to own military caliber weapons. So Imbel builds a version of the 1911 in a caliber that's legal for the populace to own -- .380 ACP. That problem doesn't apply in the U.S.