WB
Some thoughts on the 10mm 1911...
Thursday, December 26, 2019, 09:21

I have a beastly 6" 10mm I worked up on the plastic G21 platform (yes 21, not 20) for real abuse. It's simplified mechanics, beefiness, and has the "give" in the chassis to absorb the considerable forces. It is a custom gun with each part selected and considered. I've even videoed and watched in slo-mo the gun's reactions to recoil and function. It takes a pretty good beating but springs back. Plus I'm shooting a few hundred rounds, not thousands. But I do not like that type of rough play on my 1911 platform, just me.

I had a bad experience with the 1911 working with the .400 Corbon but learned a whole lot. It's a much more complicated machine with the swinging link, upper barrel locking lugs, and other little systems of John Browning's brilliance. The argument that it is a great design is irrefutable. BUT, the farther you get away from it's original design intent, things start to get fuzzy. It's a military self defense gun designed for the .45 ACP 230 gr. ball round. Turning it into a reliable rig with double the power, using modern sharp ojive bullets with flat meplats, while expecting 2" 50 yd. groups demands considerable considerations.

Doug traded me a sweet little AMT (IAI) 10mm 1911, sort of a cobby stainless "Gold Cup" with flat ribbed slide and adj. sights. Rough, but lots of potential. It must have a 30# recoil spring as I can barely rack the slide (sometimes actually can't) to chamber a round under ideal conditions. Plus it has a full length recoil spring guide rod that only makes it difficult to take down. Is that really necessary? What does that spring really do?

I did some reading, researching. I found some information claiming the recoil spring is not as critical to prevent frame battering as perhaps some other elements. Some state that a really heavy spring does more harm than good. Batters the gun on the return cycle and the slide stop/notch too.

I also read John Browning originally designed the firing pin stop plate, the little sliding plate at the back of the slide the pin protrudes from, with a flat bottom. About 99% of all 1911's today have a beveled bottom. I read that the military demanded a change to assist military trainees rack the slide easier with a "hammer down" condition. I have never heard this before. The idea is this helps provide resistance in keeping the slide locked or closed a bit longer as cartridge pressures peak and drop, and reduces the slide velocity and forces. It was a deviation from the original Browning design to add the bevel. In addition a stiff hammer mainspring, housed in the mainspring assembly under the grip safety on the back-strap, is said to help the hammer hold the slide as well as give added resistance for that "flat" firing pin stop at the back of the slide.

The reading I found was not overly profound in concept but collectively seemed pretty reasonable. I decided to explore it a bit and plan on setting up this 1911 a bit differently than mainstream. My personal goal is to set the gun up for a 200 gr. cast bullet at around 1200 fps, AND have it where I can actually chamber a round with some finger arthritis flaring up. This was the original Bren Ten and Norma 10mm loading.

My plan; Install a more conventional recoil guide system and plug with a #18-20 lb. "flat" wire recoil spring. Swap out to a "flat bottom" firing pin stop plate at the back of the slide. I reflected that I normally cock the hammer manually anyway before racking the slide. Finally add a 23-25# mainspring, I like a snappy hammer anyway. I'll change out firing pin and plunger springs while I'm at it too. The leaf trigger spring feels OK for now. I have lots of smoothing to do on the inside. I may leave the outside rough for a carry, hunting gun. There are times I carry in the woods, and while the .45 is likely plenty, I like the idea of having a like weight solid bullet at a few hundred fps more. Two extra rounds are nice too.

I do like shock-buffs as long as they are maintained and not allowed to get oily and rot. They do allow you to monitor the impressions of being mashed in recoil. Who's do you like best? It would be interesting to pick Kase's brain and get some other thoughts on the subject. Gary trained Kase well and he has done much testing and tinkering on his own. I was truly impressed with his depth of knowledge on the platform. I know he likes a custom recoil spring "system" but I hope to keep it more simplified with a single spring.