Differences between 1911 and 1911A1 - The Firearms Forum

Jackman · 11-13-2012, 08:41 AM

What are the differences between 1911 and 1911A1 ? anyone have some pics to add?

Here is my 1913 issue 1911,,,,,

Alpo · 11-13-2012, 09:21 AM

They learned a few things, during the war.

They found that, with point shooting, the 1911 shot a little low for most people. They changed the mainspring housing from flat to arched, which made the gun point higher when you held it.

They found that some folks had trouble reaching the trigger. They changed the length of the trigger, making it shorter, and they machined little notches into the frame, on both sides, behind the trigger, so short fingers could get in easier.

They found that the hammer spur would often pinch a layer of flesh between the back of the spur and the top of the grip safety, so they shortened the spur slightly and lengthened the grip safety, slightly.

The biggest VISIBLE difference is the notches behind the trigger guard. Everything else is replaceable. You can put a 1911 trigger on an A1, and vice-versa. Same with flat and arched mainspring housings, hammers and grip safeties.

myfriendis410 · 11-13-2012, 09:22 AM

The primary difference between them is the A1 has an arched mainspring housing.

Country101 · 11-13-2012, 01:33 PM

Good info. I just always figured it was an abbreviated term that didnt have any meaning as far as differances.

ka64 · 11-13-2012, 01:50 PM

One says A1.........

hogger129 · 11-13-2012, 02:04 PM

The A1 was a series of modifications that the US Army submitted to Colt. Arched housing, the recessions around the trigger, the hammer spur and sights are slightly different, short trigger.

Deacon_Man · 11-13-2012, 04:35 PM

Good information Guys, thank you.

Jackman · 11-13-2012, 09:53 PM

Thanks all and a big thanks to Alpo, nothing better than a good pic to show the details

1LoneWolf75 · 11-13-2012, 10:31 PM

Quote:

Originally Posted by Jackman

Thanks all and a big thanks to Alpo, nothing better than a good pic to show the details

+1

Archie · 12-29-2012, 11:13 AM

One other distinction: The sights.

The 1911 rear sight had a very tiny 'U' shaped notch, and the front sight was narrower than the 1911A1 (not sure of actual dimensions, but fairly subtle).

The 1911A1 (the 'A1' in military speak in those days meant 'alteration one') had a subtly wider front sight and was squared flat on top, rather than almost a point, and the rear sight notch was slightly wider and deeper and was square on the bottom.

However, one does occasionally find a G. I. pistol with a 1911A1 frame and a 1911 slide with the original sights. These are presumed to be arsenal rebuilds.

I believe it was at the 1911A1 introduction the pistols went from a polished blue finish to the more familiar, more durable and cheaper parkerized finish. The finish change may predate the 1911A1; no doubt one of our more studied brethren will correct me.

armenjs802 · 01-08-2013, 05:02 PM

magazine release and cut out wall for the extractor,trigger, main spring housing. What they should have changed was the beaver tail safety or as they say no extended grip safety.

11-13-2012, 08:41 AM	#1
Jackman V.I.P. Member Join Date: Jan 2008 Posts: 446	Differences between 1911 and 1911A1 What are the differences between 1911 and 1911A1 ? anyone have some pics to add? Here is my 1913 issue 1911,,,,, -->

11-13-2012, 09:21 AM	#2
Alpo Advanced Senior Member Join Date: Feb 2007 Location: NW Florida Posts: 8,662	Re: Differences between 1911 and 1911A1 They learned a few things, during the war. They found that, with point shooting, the 1911 shot a little low for most people. They changed the mainspring housing from flat to arched, which made the gun point higher when you held it. They found that some folks had trouble reaching the trigger. They changed the length of the trigger, making it shorter, and they machined little notches into the frame, on both sides, behind the trigger, so short fingers could get in easier. They found that the hammer spur would often pinch a layer of flesh between the back of the spur and the top of the grip safety, so they shortened the spur slightly and lengthened the grip safety, slightly. The biggest VISIBLE difference is the notches behind the trigger guard. Everything else is replaceable. You can put a 1911 trigger on an A1, and vice-versa. Same with flat and arched mainspring housings, hammers and grip safeties. Attached Images __________________ Meddle not in the affairs of dragons, for thou art crunchy, and taste good with catsup - George of Lod, Year of Our Lord 297 I always take precautions. Beware the Evil Bullet Fairies.

11-13-2012, 09:22 AM	#3
myfriendis410 Senior Member Join Date: Mar 2011 Location: Lompoc California Posts: 543	Re: Differences between 1911 and 1911A1 The primary difference between them is the A1 has an arched mainspring housing. __________________ Life's too short to shoot an ugly gun.....

11-13-2012, 01:33 PM	#4
Country101 Advanced Senior Member Join Date: Feb 2004 Location: Dardanelle, AR Contributor Posts: 2,028	Re: Differences between 1911 and 1911A1 Good info. I just always figured it was an abbreviated term that didnt have any meaning as far as differances. __________________ Gainfully employed= shooting somebody elses bullets and getting paid for it Country101

11-13-2012, 01:50 PM	#5
ka64 Advanced Senior Member Join Date: May 2011 Location: Michigan Contributor Posts: 1,412	Re: Differences between 1911 and 1911A1 One says A1.........

11-13-2012, 02:04 PM	#6
hogger129 Advanced Senior Member Join Date: Nov 2009 Posts: 4,064	Re: Differences between 1911 and 1911A1 The A1 was a series of modifications that the US Army submitted to Colt. Arched housing, the recessions around the trigger, the hammer spur and sights are slightly different, short trigger. __________________ Samuel Adams once said, "among the natural rights of the colonists are these: first, a right to life, secondly to liberty, thirdly to property; together with the right to defend them in the best manner they can."

11-13-2012, 04:35 PM	#7
Deacon_Man V.I.P. Member Join Date: Feb 2010 Location: Weatherford Texas Posts: 452	Re: Differences between 1911 and 1911A1 Good information Guys, thank you.

11-13-2012, 09:53 PM	#8
Jackman V.I.P. Member Join Date: Jan 2008 Posts: 446	Re: Differences between 1911 and 1911A1 Thanks all and a big thanks to Alpo, nothing better than a good pic to show the details

12-29-2012, 11:13 AM	#10
Archie V.I.P. Member Join Date: Mar 2005 Location: Hastings, Nebraska; the Heartland! Posts: 294	Re: Differences between 1911 and 1911A1 One other distinction: The sights. The 1911 rear sight had a very tiny 'U' shaped notch, and the front sight was narrower than the 1911A1 (not sure of actual dimensions, but fairly subtle). The 1911A1 (the 'A1' in military speak in those days meant 'alteration one') had a subtly wider front sight and was squared flat on top, rather than almost a point, and the rear sight notch was slightly wider and deeper and was square on the bottom. However, one does occasionally find a G. I. pistol with a 1911A1 frame and a 1911 slide with the original sights. These are presumed to be arsenal rebuilds. I believe it was at the 1911A1 introduction the pistols went from a polished blue finish to the more familiar, more durable and cheaper parkerized finish. The finish change may predate the 1911A1; no doubt one of our more studied brethren will correct me. __________________ Be at Peace; go forth, spread enlightenment and joy to all. Wear clean underwear and take a gun. http://oldmanmontgomery.wordpress.com/ for my thoughts...

01-08-2013, 05:02 PM	#11
armenjs802 V.I.P. Member Join Date: Dec 2012 Location: Well, one of the few banned States in US, and for the rest welcome to the GC party Southern Ca. Posts: 72	Re: Differences between 1911 and 1911A1 magazine release and cut out wall for the extractor,trigger, main spring housing. What they should have changed was the beaver tail safety or as they say no extended grip safety. __________________ Bitterly clinging to my guns/ammo /religion since 11/6/2012 Join NRA Last edited by armenjs802; 01-08-2013 at 05:07 PM..