For some reason I got to wondering if a 1911 barrel experiences any "torque" during firing. To me it makes sense that it should - as the bullet presses through the riflings it must try to twist the barrel in the direction of the riflings. If this is so, wouldn't this affect accuracy to some degree if not controlled? My curiosity just got me wondering about this while fitting my barrel hood. The way I see it the barrel will try to twist to the left during firing, so if the left side of your hood fits nice and snug, so that it slides up into your slide real snug on that left side during lockup (the left side of my hood actually leaves a small rub mark on the slide there), wouldn't this keep the barrel from "torqueing" (how do you spell that?) and be a good thing? PLEASE correct me if I am all wet - my brain has been bouncing this around for awhile.
You are not all wet. Anything that will assist with supporting the barrel will improve accuracy. It's the reason barrels always shoot better out of the barrel tester, than from the frame/slide.
The beautiful concept behind Searl's design in the Savage 1907, the barrel torque was supposed to stop the breech from unlocking until after the bullet had cleared.
Whether it did or not is subject to debate, but consider the torque involved in spinning a bullet within a tiny fraction of a second to 60K RPM. There has to be something to the idea. It's been called a loophole around Browning's patent on blowback operation but that belittles Searl, and I feel he was something of a genius.
When a round is fired in a 1911, I believe the slide and barrel stay locked together for about .100" of rearward movement before the barrel starts to link down. A properly fitted slide stop pin should help to decrease torque, since the barrel can not twist/move when the slide stop pin is riding along the flats of the barrel lugs.
If this is correct. how much torque is experienced at the hood? I have seen posts that say the clearance on the sides of the hood extension on the barrel don't make much difference, but I always try to fit the hood extensions of my barrels around .001" on the rear and sides. I have proven that the distance of the rear of the hood to the breech face is very important to accuracy, so getting about .001" is my goal. How much clearance is ideal for the sides of the hood in the breechface? Does a close fit on the sides of the hood extension help to further reduce torque? I think it would be very minimal...
Interesting subject. I have found several factors exert influence on the overall outcome. Also, ramped barrels tend to produce better groups. The larger lower mass of the ramp, when fitted to the frame channel with minimum clearance, aids in the transfer of torque to the frame, and support for the barrel. Therefore, attention to minimal lower lug clearance on standard barrels has been productive.
I strive for very close fit on the hood also, and it is true, this area is in a poor position to provide a great deal of support against torque, but every little bit helps. The quality of hood fit is dependant upon how precise the alignment between the lower lugs/frame and slide C/L is. The barrel must cycle in a precise path, or small collisions and interference will occur.
Also, a huge factor, is the relationship between the slide/barrel upper lug radius. If a mismatch is present, the barrel will never align properly to operate at the close tolerances, necessaary to produce the best possible accuracy.
The point made about the barrel lugs and slide stop contact is especially interesting, concerning barrel torque.