Mainspring housing

[mayagrafix]

Is there any technical reason why a straight MSH (main-spring housing) would be replaced with an arched MSH?

I have a 1911 GM (1920 production) that came with an arched MSH but my guess is that it originally had the flat MSH and it was changed to the latter M1911-A1 rounded MSH. Also no lanyard loops either on the MSH or mags.

[daysleeprx]

Personal preference?

[Ericthenorse]

I believe the early ones came with arched housings... It was supposed to mimic the grip of the revolvers they replaced... You just said yours is a GM... Unless it is a military pistol that says Property of the US Army on the frame, then it is a civilian model, and would not have come with lanyard loops....

[1911Tuner]

The pistols built prior to 1924 were equipped with flat, non-serrated/checkered mainspring housings, and all had the lanyard loop...whether commercial or military. The arched housing was one of the modifications implemented on the "1911 Improved" that was to become the
US Army Model of 1911A1. Commercial versions were simply designated as
"Government Model."

Here is a reblued, but otherwise original commercial/civilian Colt Government Model built in 1925.

http://i40.photobucket.com/albums/e243/1911Tuner/25Colt.jpg

[1911Tuner]

Here is an original 1919-production military Colt. Note the differences between the M1911 and the M1911 Improved. The mainspring housings and the triggers represent the most obvious changes, but take note also of the scalloped cuts at the rear of the trigger guard on the '25 that aren't present on the '19.

http://i40.photobucket.com/albums/e243/1911Tuner/Colt.jpg

[mayagrafix]

Thanx for the pictures Johnny. My GM frame is like the 1919 model in your second picture but with the newer arched housing. My guess is that it was replaced at some point. Why? Do they (MSH) break or go bad for any reason? is there a benefit to be gained by having a arched MSH instead of the other?

Can the lanyard loop be re-installed as shown in your #2 picture?

BTW, nice pair of puppies you have there :)

[1911Tuner]

The arched housing was implemented to combat the tendency of a shooter to point the gun low under stress. The change to the long trigger, along with the scalloped areas at the rear of the trigger guard were done to make it easier for troops with smaller hands to reach the trigger. Incidentally, the triggers in the early pistols were one-piece, milled from a solid block of steel.
The long triggers were smooth-faced, and the short ones were checkered.

The other changes were done to make the pistol more user-friendly. Namely, the longer grip safety tang and shorter hammer spur to prevent hammer bite.
The 1925 commercial GM pictured still retains the long hammer spur. Shortly after this one was produced in late May, the shortened hammer spurs began to show up.

Better sights were installed, which my 1925 doesn't have, retaining the same sights as the 1919. A more subtle change is the slidestop. Can you spot it?

In the picture of the 1919 Colt...the pistol on the table is a late August production Remington Rand, and about as nice an example as you're likely to see. All three...like most of my USGI pistols...are unaltered, and will feed and function with hollowpoints, and even 200-grain lead semi-wadcutters equally as well as with hardball...even from the original "Hardball Only" GI magazines.
Both the 1919 Black Army Colt and the '25 commercial will shoot into about 4 inches at 50 yards from a rest with PMC ball. The Rand hasn't been targeted at 50 yards yet, but will mow 8-inch plates down on the falling plate machine at 25 yards with boring regularity...at least for the 50 or so rounds that I've put through it. None are "Rattletrap" loose, and none produce damaged brass through the small ejection ports.

If you want to replace the arched housing with something as close to original as is commercially available, you can order a Smith&Alexander smooth, flat housing with lanyard loop from Brownells for about 45 bucks. They don't have the small clearance groove under the loop, but are nicely finished and they're a dead ringer for the originals to the casual observer.

[RickB]

If you look at the production figures for the M1911 (1912-1919), you'll see that more pistols were made in 1918 alone, than in the other years combined. The gun went from being fairly rare, and little-used, to ubiquitous; it was the intent of General Pershing that every U.S. soldier have a pistol. After the gun had been in use by hundreds of thousands of soldiers in combat, it became clear that certain "improvements" should be made. The arched mainspring housing was intended to correct the tendency of the gun (that is, the shooter) to hit low when pointing, rather than aiming the gun. I learned to shoot on an arched housing, and if I try to point-shoot a target that's ten feet away, I'll hit six inches lower if the gun has a flat housing, than with the arched to which I'm accustomed. I suspect it would work the other way around too, only shooting high when switching to the arched housing.
Today, with both available, it's a matter of preference. I truly think the enduring popularity of the flat housing is due to perception; the Gold Cup had a flat housing at a time when all other 1911s had arched ones, so when someone wanted a "match" psitol, they wanted that flat housing, even though they may have found that they would shoot better with the arched one.
We often copy what we see others doing, when they are successful. Everyone wants to use the same sights or hammer, or trigger, or recoil spring as the guy who wins the competitions, or we copy his style, hoping to be as successful. Even though probably 90% of the 1911s sold have flat housings, both Rob Leatham and Doug Koenig, the two most successful competition shooters of all time, use arched.

[1911Tuner]

Here's a closeup of the Rand in the background.

Rick...I use the arched housing/short trigger on my carry guns, and on my pistols that I practice defensive shooting with. For pure, slow-fire shooting at 25 yards, and on the falling plate machines...when I'm in the mood to go play instead of serious practice...I use the flat housing/long trigger arrangement. I have fairly large hands, and do about as well with either for either exercise, but stick with the arched/short for fast work because it does negate the tendency to point low...and I practice point-shooting almost exclusively during that type of work.

Here's the Rand. Purty...ain't it? :cool:

http://i40.photobucket.com/albums/e243/1911Tuner/45RR.jpg

[gbw]

"Here's the Rand. Purty...ain't it?"

Man, that's what I'm Talkin' about!

[berkbw]

The really best way is to TRY them yourself.... WAIT - it's actually easy - just buy the other kind + I usually buy a spring kit and a pin kit. Assemble the new MSH (we'll tell you how), stick it in and try it. In general, if your shoe size is 9 1/2 or less, you'll favor the flat - larger, then you'll probably like the arched. These parts are very affordable, and easy to work with.

b-

[clughog]

Well, that explains it berkbw! My shoe size is 9 1/2 and I like shooting the flat and the arched equally (and I'm equally as inept at hitting the target!). But I just personally like the looks of the arched MSH a tiny bit better because that's what I carried in the service! Great suggestion to get the flat one and see which feels the best.