Just wanted to add my experiences using the 01 and 02 springs. I wasn't sure whether to add to an old thread or start a new one...

Took a handgun class Saturday and Sunday and shot around 500 rounds for the whole weekend. The story of my G17 up to now: I bought it about 6 months ago, new from a local shop, which came with the 02 spring. Have never cleaned it. I've only shot PMC Bronze 115 gr so far. I think I went up to 500 rounds and no malfunctions, before I took the class and have still not cleaned it. Field stripped to change springs, but no extra lube or anything.

On Saturday, I stuck with the 02 spring for 1/2 the day and 100 rounds. No problems.

I switched to the 01 spring. During the next 75 rounds I got two double feeds, which made my instructor happy as a clam so he could bark out the orders of clearing the gun while I scrambled. In the evening there was an IDPA classifier so I went back to the 02 spring just to be safe. No problems except 1 stovepipe which fortunately happened at the end of a string. This never happened with my new Glock until now. I did have a really long day of shooting, so I think I can blame myself and not the pistol.

Sunday, we shot about 300 rounds. I still had the 02 in and I shot the first 50 rounds of the day without a problem. I switched to the 01 thinking it was still early in the day and I wanted to rule out fatigue as a cause of the problems.

100 rounds later, no misfeeds but during some shooting-while-moving drills I did get 1 failure to go into slide lock after my magazine was empty: I surprise dry fired, tap-rack and then the slide locked open.

Right after that, I then did a real light cleaning and lube for the first time since I bought it: field stripped, used some Break Free to put a light coat on the rails, slide, barrel, and the trigger connector. Dry brushed the breech face and extractor. Used some q-tips to wipe the slide. No problems after that. I shot using the 01 for the rest of the day which as at least another 200 rounds. Guess I'll keep the 01 in for now so I can get more mileage in.

I have to go back to my notes to figure out what drills I was doing when I had the FTE's...

You really should clean your Glock more often. Thanks for the range report about the springs.

will do. I won't keep it as uncleaned anymore