I'd like to discuss this, and have it continue as a discussion and not as a pissing contest which it is currently nowhere close.Not to take away from all of the above mentioned reasons, but a big one is that it's easier to get back in the fight. If you run across a hard primer, or any other "click, no bang" scenario, it's much faster to get that shell out of the chamber, re-chamber, and get back on target with a pump, and I don't think anyone would try to dispute that.
Now having said that... I currently have one of our R&D Bored&Ported 930s sitting beside, but it features overbored gas ports, reduced weight firing pin spring, increased power hammer spring and a very long list of modifications aimed directly at reliability, not the least of which being a fully polished chamber which, in my opinion, is a MUST for any 12ga.
Take Care,
Mike
I have some points and past history to bring up for my side of the pump vs auto.
Most of it is training. I've posted before that I've hunted with a guy in the past that used a Rem 870 wingmaster that only had one arm and he could do a great job of racking the slide. He had a method where after the first shot,(shouldered) he would basically drop the gun from his shoulder and with an up and down motion get a new shell into the chamber, finally re-shouldering the gun to fire again. He pretty much had it down to a art as he had never been with two arms since birth. Was he fast? No. And there were failures? Yes, but darned few as he had thousands of rounds under his belt shooting like this.
I currently own or have owned three pump guns. A Mossy 600AT(to be corrected, it was stolen years ago and the model number may be wrong) Police only issue with an 18" cylinder choke barrel, and a receiver that was threaded and would accept a scope mount. 3" chambers.
Every time I shot a 3" round through it, the forearm would fall off. WTF? The threads were perfect on both the gun and the forearm showing no signs of being stripped and tightened up snugly after falling off. I know threads, and machining. Single point threading is something I'm really good at with three lathes at home to play with, two being conventional metal lathes.
The threads had to be out of factory spec is the only answer.
Second is a Mod 12 Win from 1928 that I've restored to new condition with a rust blue and new stocks. This thing runs like a clock. Zero failures ever.
I've only shot trap or 5 stand with it as it has a fixed full choke.
Finally a Rem Wingmaster from the 70's. Great gun, no failures. Mod fixed choke
Why a semi auto for me?
I haven't perfected the one arm reloading of chambering a pump gun if one arm is disabled and a guy that spent a lifetime doing it hasn't either.
Limp wristing a semi auto can certainly result in a FTE, but in my personal training, I don't limp wrist one, but bring it to the shoulder or the hip, the thigh, the calf, where ever one needs to do that. If I do shoot it one handed or limp wristed, a full extension of the arm with the elbow locked or mostly locked will cycle the gun.
I've reloaded many thousands of shells on everything from a $25 Lee loader to my current RCBS Grand loader and have never experienced a hard primer or a fail to fire because of primer issues. Even on many thousands of rifle or pistol rounds. I shoot competition. Those things are just so reliable these days that it's almost unheard of.
If perchance that ever happens, the slide on a semi can be racked on a door frame, the side of the leg, (which will hurt like hell) or another piece of furniture or at worst case, on the carpet with the gun turned at a 90 degree angle, sliding it on the floor to cycle the action. Lots of options.
Ok, I'm done for now.
The mods you are talking about for reliability in the 930 are similar to the same that we use to make our competition rifles more reliable.
Lighten the trigger springs, lighten the hammer, etc.
I'm interested in why you polish the chamber? Would not a long day of shooting clays or trap negate the polish or does it keep the carbon caused by back splash washed off?