I have three 1911s, but none with an arched MSH.
Can anyone tell me how the arched version affects the shoot-ability of 1911 pistols?
Thanks!

It changes where the gun points by raising the muzzle a bit.If you have large hands,combining it with a long trigger and even thicker grips will help it fit your hand better.I prefer the feel of a long trigger and a flat MSH,but arched with a long trigger is a close second.Arched with a short trigger takes too much fiddling getting my trigger finger placed properly.

The change to the arched mainspring housing (MSH), as I am sure you know, came about to improve the grip of the shooter. The design was to "fill the shooter's hand" and the serrations or checkering on the back of the arched MSH were to improve the grip as well.

That being said, I have 1911's with both styles of MHS(s) and notice no difference of point of impact or accuracy. The 1911A1 style does "fill the hand better" but, the straight MSH(s) that come on most new style 1911's are, for the most part, checkered and provide, IMO, a very comfortable grip.

The only real difference may be how your hand feels after an extended shooting session. The 1911A1 style MHS may have a slight advantage but, this again is only my opinion.

I have the Colt 1991 Government Model that came with the Long trigger and flat MSH. The flat MSH , for me, left the sharp edge of the grip biting into my hand while shooting. So I replaced it with an Arched MSH and short trigger and like it much better.

With many of the current 1911 model pistols being made with the flat MSH I find it interesting that companies like (I think) Wilson now make a 1911 with a round butt for a couple thousand $ as a supposed improvement over the flat main spring housing, when a 5 or 10 dollar arched main spring housing will do the same thing. Sometimes it seems people have to reinvent the problem in order to find a more expensive and complicated solution to a thing that was fixed back in 1926.

__________________
A Snider squibbed n the Jungle

I understood the rounded butt to print less and no snag draw for conceal carry, not grip.

To me, choice of MSH is more about preference/fit.
However, as Arjay pointed out it may make a modest difference in POI for some folks. My POI did change when fast point shooting beyond 7yrds, while using an arched housing magwell. Once I have the time to acquire the sights either style is fine.
I can work with either, but prefer flat housings with my choice of trigger.

I have always used a flat MSH, prefer it to arched. A flat MSH was the way John M. Browning intended it to be.

As has been mentioned, the arched MSH changes your natural point of aim. I had to put them on my 1911's because I was always fighting it. Now I can aim at target, close my eyes for a couple of seconds while still aiming, and when I open my eyes, I am still on target. With a flat MSH the front sight would dip on me it amounted to the difference between a dead center hold and a six o'clock hold, your mileage may vary.

Personal preference as to what works best. For me, flat

It's a pity that Pachmayr keeps pulling their semi-arched checkered rubber 1911 mainspring housing from production. It's an excellent compromise between flat and full arched, and helps a bit with recoil. I have one on my Colt 10mm Gold Cup. Next time they make another run I'm gunna pick up a couple and squirrel them.

As for the flat housings, they don't fit my hand very well. I prefer arched or especially semi-arched.

Another idea is Hogue makes mainspring housings from G10 (a plastic laminate). If the arch is too much, you could clamp it in a vise and file them to an arch more suitable to you.

https://www.hogueinc.com/grips/1911/...ng-housing/g10

The original 1911 had a flat MSH. When the modifications were made to create the A1 Model it was changed to an arched housing because soldiers complained that the gun shot low. Changing the MSH was a simple fix for the problem.
Frankly, the current trend of most 1911 makers to go back to the flat housing irritates the hell out of me. I like the arched version and it annoys me that I buy a brand new gun and immediately have to change the MSH to make it fit my hand.

I have 1911s with both flat and arched mainspring housings. I personally can't tell the difference when I am shooting them. I prefer the looks of the flat housing. There is probably something to the idea that the difference in grip can effect the point of impact, but after having shot 1911s for 47 years in NRA Outdoor Pistol and duty carry, I can't tell the difference. At times I have competed with two 1911s in a match, one with an arched housing and one with the flat.

__________________
Keep Shootin' and check 6

I vote for the arched as it fits my hand better,you just have to try both and see for yourself.

__________________
Hue 68 noli me tangere