What do I have?

The diamond D type three band was produced by Donaldson Company, Inc in St. Paul, MN. Late war.

Ref. CC NL 356-5

IMARANGEMASTER, you may be correct on the cutdown sling swivel. Looking from the front, it looks like saw marks on an inner layer of steel. Also, can you tell me if a 7.62x51 m80 ball round would work for a muzzle guage?

I believe the M2 30-06 and the M80 7.62x51 use the same 150 grain bullet. It should be close, anyway.

Looks like a nice carbine.

The bolt finish looks odd to me, but I don't know much. The other guys might not think so. I think an original one would be blued. But I have a flat bolt that's parked. It's more green though. Probably done at rearsenal??? Maybe. I'm assuming if someone cut down the Type III band that they were going for a WWII look without getting a different barrel band.

I believe the 'RA' is a Raritan Arsenal (Edison, NJ) rebuild. The 'P' is a proof mark. Too bad about the barrel band being a cut-down III (originally had the bayonet lug after the rebuild). I think the original band was a Type I. But on the good side, the Type II and III bands definitely hold the carbine together better in firing than the Type I, which was the reason they were developed. Hand guard is Inland (Overton). Looks like a decent example and has the original barrel (or close to it, I think). You can try a 7.62x51 cartridge - if it shows some copper between the muzzle and case mouth you should be good. If it swallows it, the barrel may have been counter-bored during the rebuild to get rid of cleaning rod wear. You probably can see the ring where they stopped maybe 1/4" or so into the barrel. Otherwise it's a big muzzle that probably won't group very well but will still do it's intended job.

I used the m80 ball round, kind of pushed it in snug. Used dial caliper to measure. I get .155 of inch between top of muzzle and the brass. Its not been counter bored. Bore is very bright with no pitting. I am guessing that it has been shot very little. Any idea what this carbine may be worth? And any suggestions on where would be the best place to try to sale it?

Sounds like the barrel is good. I don't see why you couldn't get $750 for it. I may be wrong because I don't have any carbine books, but memory is insisting that 503xxx may be in the first M1A1 block.

Please excuse my ignorance, but what do you mean "M1A1 block"?

M1A1 has a folding stock. Some call it a paratrooper.

1st. production run around 71,000 about serial number range 42,000 to 850,000.

2nd. production run around 70,000 about serial numbers range 5,150,000 to 6,700,000.

https://www.milsurps.com/images/impo...08/M1A1s-1.jpg

Careless of you Jim, to leave that stuff lying around the living room floor...