M1A1 with Low Serial Number

[signal_4]

Had a chance to play with an M1A1 at work today. This Thompson has been in the inventory for a few decades. Serial number in the 280k range and matches the serial number on the lower. Rear butt stock and fore grip look like its from a 1921/28 but the receiver is uniformly stamped M1A1. Its not like the other M1s Ive seen that have gone under reconfiguration where the A1 is stamped separately on the receiver and usually in a different font. The lower has a matching serial number to the receiver. Pretty cool !

Edited July 26, 2022 by signal_4

[jim c 351]

Looks like someone fitted a 28 trigger group to a M1A1 receiver.

Not sure how they managed matching numbers. Maybe with a grinder and some stamps.

Jim C

[TD.]

signal_4,

 

Thank you for posting!

 

I believe this Thompson has the correct M1A1 frame but a 1928 butt stock. I wonder if the inside of the 1928 butt stock where it joins with the frame is glass bedded. I would like to see a picture of the butt plate. The fore grip may be a Savage grip; I just cannot tell from the angle. Remove the grip and see if the letter "S" is stamped in the grip channel.

 

Question: Does your department have or had Colt Thompsons in inventory now or in the past?

[giantpanda4]

There is a conversion for an M1 frame that will allow it to take only a 28 slide on stock. DR sold it as well as others. You have to mill off the bolt boss in the frame though, so you really cannot go back once you do it! I have one here somewhere if I didn't sell it already.

[ppgcowboy]

The trigger housing looks to be m1a1.

[DARIVS]

Interesting mix of two guns.

[signal_4]

Ill try to convince them to pull it out of the safe again so I can get a longer look at it. My big question is the low serial number for an M1A1. They might have had the colts in the past but this is the only one I know of that they still have. Im sure any original colts found their way into peoples private collections a long time ago lol.

[anjong-ni]

Are the rear sight ears extra-tall (locally-made?) or is it the angle? Phil

[signal_4]

I got to take another look at the M1A1. The lower is definitely for a M1 /A1 style and probably original to the receiver on matching serial numbers. I could not find any arsenal markings on the receiver or AOC or S underneath the receiver by the grip mount or behind trigger guard on the lower. Am I correct in thinking that because of the lower serial number its among some of the first official M1A1 produced on the lines.

[Countryboy77]

I think your supposed to unscrew the grip and look for a stamp on the top of the wood grip.While at it you should check for markings in tge wood forward grip too

[signal_4]

Judi going by the lower serial number of an M1A1 does anyones have any possible insight on the receiver

[Countryboy77]

The NO before the serial number in the receiver makes it a savage made gun if that helps. Ao made guns are marked No with a small o prefixing the serial number.So im guessing all parts originally should have a small s marking be it a round s or a boxy s,though any parts would be correct after arsenal rebuild.Will that stock actually slide off or is it screwed on Edited August 12, 2022 by Countryboy77

[signal_4]

 

The NO before the serial number in the receiver makes it a savage made gun if that helps. Ao made guns are marked No with a small o prefixing the serial number.So im guessing all parts originally should have a small s marking be it a round s or a boxy s,though any parts would be correct after arsenal rebuild.Will that stock actually slide off or is it screwed on

[signal_4]

 

 

 

The NO before the serial number in the receiver makes it a savage made gun if that helps. Ao made guns are marked No with a small o prefixing the serial number.So im guessing all parts originally should have a small s marking be it a round s or a boxy s,though any parts would be correct after arsenal rebuild.Will that stock actually slide off or is it screwed on

 

 

Ok. Thanks ! The butt stock screws on.

[Countryboy77]

Shes nice but would be nicer in my eyes if correct wood was put on her ,horizintal foregrip and correct stock.Somone was trying to make her handle like a 1928 or a 1921.Wouldnt be surprised if they had an adapter drum. Edited August 12, 2022 by Countryboy77

[signal_4]

Shes nice but would be nicer in my eyes if correct wood was put on her ,horizintal foregrip and correct stock.Somone was trying to make her handle like a 1928 or a 1921.Wouldnt be surprised if they had an adapter drum.

Ya I totally agree ! I told them they needed to make it historically accurate or just sell it to me at the employee appreciation discount at 1k / per year of service 😂 which would make it almost free !