Re: Gen4 Glock
Put it this way. On our pistol frames in our company, We had about 40 pistols 100,000/200,000+ rounds in the weapon data books. They got rebuilt with new barrel, slide etc and the only things that were reused if serviceable were the frames.I personally put 50k down range in my pistol. I love my glocks but they wouldn't hold up to that sort of abuse. You can already see frame wear on my glock and it only has about 17000 rounds on it (my competition glock). In the context of normal civilian shooting glocks will last most people a lifetime and are great pistols. But when we are talking about a service pistol alloy frame is the way to go. Not trying to have a pissing contest just sharing information. We were at the range shooting 4 times/ week. Each school/ class probably averaged over 2k pistol rounds and 2-5k rifle rounds. There is a reason they said it cost 1/4 mil to train us. But in the end my statement was based on the service pistol IIRC ($1800 custom 1911), not a recreational use weapon ($500-$600 off the shelf polymer frame pistol).
Lead guy, Keep in mind for every guy that says he shoots lead bullets ok. The MFG and a butt load of glock shooters say don't use lead bullets. Hence why I passed on the gouge of don't use lead bullets. I have seen 6 cracked frames in glocks. Just like if you ask 30 people their favorite bullet you will get 30 different experiences. Find me a glock frame that lasted 800,000 rounds and I will buy you a cookie (we had the grampa pistol frame with 800k rounds through the frame in our company). It's not miss information, it's experience and 5 months away from a Bachelors degree in Mechanical Engineering.
Polymer frames aren't made for ultra long service lives. They are made for high production numbers, the molds themselves are very expensive but the actual material cost is small (the plastic). In large production runs the polymer frames are more cost effective. But when you bond steel to polymer your adding stress risers to the assembly because the steel and polymer don't have the same compression/ elastic properties. IE with any movement or forces applied there is stress. Applying stress to a substrate that is a monomer there is less delta in movement than with a comparable polymer frame.
To sum it up, the life cycle that I am talking about is well above the average USPSA shooters pistol life cycle. 25% of shooters shoot over 1000 rounds/ year. I only know about 70 people that have shot a pistol barrel out, and 67 or so of them were from my company in the Marine Corps. Most people will never shoot out a pistol barrel, let alone wear out the frame.