Ok, I measured the front of the frame before the grips, the rear of the frame past the grips and one right on the middle of the grip, just below the trigger guard. I also took a measurement from the beavertail around the trigger and back, with grip safety depressed to simulate total trigger reach.
Worth noting:
- I don't know which grips the RIA double stack uses, so it's possibly thicker than my Remington, which is based off the Para 14.45, I doubt it could be any thinner but I'm not sure.
- my RIA Tac 10mm has a shorter trigger than my Rem R1, not quite a quarter inch but maybe an eighth?
- my RIA Tac 10mm has pretty beefy grips, so I also measured my Kimber Warrior with Simioch Gunner grips also.
Measurements:
RIA Tactical 10mm single stack
Front strap: .771"
Back strap: .771"
Mid Grip: 1.30"
-- Kimber mid Grip: 1.28"
Trigger reach: 6.5"
Remington R1 Enhanced Double Stack
Front: 1.16"
Back: .761"
Mid: 1.335"
Reach: 6.75"
As was noted above, the major difference is the fat front of the grip which does feel pretty fat. It doesn't bother me to shoot, two handed, very comfortable but feels fatter than my Glock 21 (which feels longer back to front but thinner side to side), I have larger hands, usually wear a large glove for a tight fit or XL for a more comfortable fit.
My one issue with my R1 double stack is shooting one handed with my thumb on the safety as part of my firing grip doesn't always disengage the grip safety, something that single stack 1911s are not effected by, perhaps a "bump" in a news grip safety could fix it, but it did push it out of the carry consideration category.