I'd say a 1911 ejecting cases 20+ feet, is working harder than one ejecting 6-8 feet; agreed?
The gun ejecting cases 20+ feet has the higher slide velocity, impacting the frame harder, and excessive slide velocity is believed to contribute to frame battering?
Or, a 10mm with 25# mainspring and 24# recoil spring, which ejects cases 20+ feet, is working harder than a .45 Super, with the same springs, ejecting cases 6-8 feet?
A lot of people think a 10mm must have a fully-supported chamber to shoot "real" 10mm, lest they blow a case head, but even full-power .45 Super (230 grains at measured 1190fps max, 1175 avg.), shot in my unsupported .45 ACP chamber, shows no unusual case expansion or other pressure signs.
The gun isn't working hard, the brass isn't working hard.
The surfaces of a 1911 you are concerned about "battering" at the end of the slide's rearward journey were designed for it.They do OK.
Remember its all dollied up by your hand.Semi-squishy.
Yes,slide velocity matters.Aside from details like firing pin stop radius,mainspring,porting,comp,etc its not directly about pressure (the 9mm pressure vs 45 pressure comment)
Its a recoil operated gun. Generally,the 9mm is less recoil. Think about the barrel link down . The Chamber end of the barrel dropping. When does the bullet exit the muzzle vs link down? Pressure drops quick after bullet exit.
Pressure plays a part in the physics of recoil,but slide velocity is launched by recoil.
Slide velocity does play its part in ejection distance.Thats true. Extractor tension and the length and bevels on the ejector play a role,too.
If battering the gun is a concern,IMO, a 24 lb spring is not the answer. Its forward slide velocity that batters the gun,
They call it "Slide stop" for a reason. The buck stops when the feet of the barrel underlug come to rest on the slide stop pin,which transfers the energy to those two .201 dia holes in the frame. That fitup is where a great deal of getting a 1911 correct lies. Beating it with a 24 lb spring is counter productive.
What I have worked out for myself (you may disagree) if I want to load "warm" I'll put in an 18 lb spring. When putting 1 round in the mag I want the load just hot enough to hold the slide back on the last round, the ammo is as hot as I want to run it. I switch to a 16lb spring for reliability. I might chrono the load for curiosity,but I load for the gun.not the chrono. A 16 b spring is in the ballpark of the John Moses design. If its 850 fps or 1050 fps,I don't care. Its balanced to function with a 16 lb spring.
I.ve mentioned this gun before, We have a Ben Jones /Guncraft single stack 38 Super race gun in the family. It was the gun of a pro competitor. It shot high round count ,1400 fps 38 Super Old School Major loads that are around 40k psi. After 40+ years its tight,slick,and sweet. Not beat up at all.
Little brother brought home high speed industrial camera to determine what recoil spring worked best with the comp. That gun shoots flat,sweet,and reliable at 1400 fps with a 124 gr bullet and Power Pistol using a 12 lb recoil spring.
As I understand the 45 Super case, the main idea was to thicken the web area to cover the unsupported part of the chamber. It was designed for unramped,unsupported chambers. So long as efforts with unlicensed Dremels don't "blend and polish" the chamber support away,it should work fine.
Look at a "cone breech" bolt gun like a Springfield or Win M-70. You could say there is quite a bit of "unsupported chamber" Case web design makes it possible.
