1960 Colt 1911 38 Conundrum

[cfullgraf]

Both calibers are headspacing off the rim on the nub at the top of the chamber. Sorry for the technical terms, im not well versed in 1911s.

FYI, the "nub" on the barrel as you called it is generally called the "hood".

Up until the 1980's to 1990's, 38 Super barrels were chambered to head space off the rim. It was one of the reason 38 Supers had lack luster accuracy. Of course, there were only a couple of manufacturers making 38 Super guns at the time.

In the 1980's, competition shooters got interested in the 38 Super due to the greater magazine capacity and better ease of making major category. They found if they chambered the barrel to head space off the case mouth, accuracy improved greatly. Eventually, the manufacturers followed suit and just about every new barrel made these days for a 38 Super will head space on the case mouth.

Just a bit of trivia.

The barrel that came with my modified 38 Super 1911 has a sleeved chamber. 38 Super ammunition would not chamber.

The 38 Super case is just a bit larger in diameter down near the base of the case than a 38 Special case.

Since your barrel chambers 38 Super ammunition, I suspect your barrel's chamber was just lengthened to accommodate the 38 Special ammunition.

If your barrel has the same external dimensions of a standard 45 ACP barrel, it would be fine and safe for shooting 38 Super with the appropriate recoil spring. But accuracy will suffer.

I'd get a new barrel, bushing and recoil spring fitted to the gun, keep the 38 Special barrel and have fun with both cartridges in a 1911.

 

[cfullgraf]

Here is my mid-1950's vintage 1911 that had been converted to shoot 38 AMU ammunition. I shot a few rounds of 38 Special through it after I got it. I converted it back to 38 Super and then a few years ago fitted a Kart 38 Special barrel. I'm having issues with the magazine feeding the last round and have not had time to fiddle with it recently.

 

[BigBlue 94]

Found some threads on the colt and 1911 forums that describe what was done to these by various 'smiths. Even found one i started here and forgot about 4 years ago.

Ill need to take it back apart to look for any engravings left by the smith.

I think ill just keep it as is, and shoot wadcutters out of it. Ill sell my 38 super ammo and magazine.

 

[CapnMac]

Please note that OP's photo of the barrel is engraved "38 super."
Now whet we won't know is whether it was an "old" off-the-rim or a newer model. I suspect the former more than the latter. This will matter in what ever "tweaks" were applied to make this a WC shooter.

From memory, this was considered an "easy" operation as it was getting a lower-pressure round to "run" in a HP barrel.

 

[BigBlue 94]

Please note that OP's photo of the barrel is engraved "38 super."
Now whet we won't know is whether it was an "old" off-the-rim or a newer model. I suspect the former more than the latter. This will matter in what ever "tweaks" were applied to make this a WC shooter.

From memory, this was considered an "easy" operation as it was getting a lower-pressure round to "run" in a HP barrel.

The 38 super round when loaded was not sitting fully in the chamber. When the semi-rim hit a small nub under the barrel hood, it stopped. There was about 1/16" of case forward of the extractor groove showing. The only visible step in the chamber was 1.075" in the chamber, from the extractor groove face. Meaning if a 38 special is chambered, its around 1.2" from the rim of said 38 special.

Ill try to get a pic of each round chambered tonight.