The 1911/1911a1, more so then any USGI gun I know of is made so as the parts are completely interchangeable. What you can do is compare the slide (make) to the serial number of the frame to see if they match as different companies were assigned different serial numbers.
Here is the problem. This is just one man's story (mine) and I'm sure there are hundreds if not thousands similar stories out there about the 1911a1s.
I went to Military Police AIT at Ft Gordon GA in 1966. At one time, I screwed up (don't remember what I did, it was Oct. 1966). I and another guy were put on detail cleaning hundreds of 1911a1s used by the MP School. We had an assembly line running where we disassembled the pistols, separating the parts, cleaned and put them back together. There was no effort to get the original parts back into the same gun. We did have fun, playing games, seeing how fast we could get them back together, blind folded, timed, etc.
Fast forward several years. I was running the Marksmanship Unit for the Alaska National Guard. I ordered and got several 1911a1s for unit marksmanship training. I got 4 for each battalion and separate company PLUS I kept 10 in the Marksmanship Unit for the Combat Pistol Teams.
Before I released the pistols to the respective units, I had a couple of my better pistol shooters go through all the guns, switching parts back and forth until the 10 I was keeping were good shooters, accuracy wise.
I also did the same thing to my personal 1911a1, I have two slides, one is a Colt, the other is a Union Switch and Single Company. The Colt slide was modified with better, high profile sights. The US&SC I left original. The frame on my 1911a1, according to the serial number is a Colt. I used the Colt slide w/high profile sights for civilian matches, and the US&SC for Military Combat Matches (where "as issued, arms room guns" were required").
I'm posting this as a warning that you cannot tell if a 1911a1 is original except for the slide matching the frame's serial number. I keep reading post where people say their pistol is original, all matching parts, etc, and, (correct me if I'm wrong) there isn't any way to tell what internal parts came from what gun.
Frankly I don't think it matters, as mentioned, the parts of these pistols are interchangeable. Just be carefully when one tells you THIS GUN HAS ALL ORIGINAL PARTS. The frame and slide should match, the rest doesn't matter.
This is two pictures of the same gun:
Colt Slide
Union Switch Slide:
Here is the problem. This is just one man's story (mine) and I'm sure there are hundreds if not thousands similar stories out there about the 1911a1s.
I went to Military Police AIT at Ft Gordon GA in 1966. At one time, I screwed up (don't remember what I did, it was Oct. 1966). I and another guy were put on detail cleaning hundreds of 1911a1s used by the MP School. We had an assembly line running where we disassembled the pistols, separating the parts, cleaned and put them back together. There was no effort to get the original parts back into the same gun. We did have fun, playing games, seeing how fast we could get them back together, blind folded, timed, etc.
Fast forward several years. I was running the Marksmanship Unit for the Alaska National Guard. I ordered and got several 1911a1s for unit marksmanship training. I got 4 for each battalion and separate company PLUS I kept 10 in the Marksmanship Unit for the Combat Pistol Teams.
Before I released the pistols to the respective units, I had a couple of my better pistol shooters go through all the guns, switching parts back and forth until the 10 I was keeping were good shooters, accuracy wise.
I also did the same thing to my personal 1911a1, I have two slides, one is a Colt, the other is a Union Switch and Single Company. The Colt slide was modified with better, high profile sights. The US&SC I left original. The frame on my 1911a1, according to the serial number is a Colt. I used the Colt slide w/high profile sights for civilian matches, and the US&SC for Military Combat Matches (where "as issued, arms room guns" were required").
I'm posting this as a warning that you cannot tell if a 1911a1 is original except for the slide matching the frame's serial number. I keep reading post where people say their pistol is original, all matching parts, etc, and, (correct me if I'm wrong) there isn't any way to tell what internal parts came from what gun.
Frankly I don't think it matters, as mentioned, the parts of these pistols are interchangeable. Just be carefully when one tells you THIS GUN HAS ALL ORIGINAL PARTS. The frame and slide should match, the rest doesn't matter.
This is two pictures of the same gun:
Colt Slide
Union Switch Slide:
