Well I have first hand knowledge of this. I had a model 21 that let go, case blew out in the spot that is not supported. It blew parts out, bloddied may strong hand and locked the gun up into a paperweight. I took it over to Glock (20 minutes from my house) and they looked it over: Not new ammo= no new gun. They gave me the option to fix it for 300 bucks or swap it for a new gun and 350 bucks to make the deal. I wasn't happy, to say the least. I told them if I couldn't shoot a reload/remanufactured cartridge in the gun, I can't own it. I shot Glock matches for 12 or so years, had 7 of their guns, verbally sold dozens of guns to my shooting buds, and always defended their product thick and thin. The rep just stood there with the "can't wait to go to lunch" look on his face and said "you heard the offer that we made"

Well I took the trade for a new model 19 9mm, walked out, haven't shot Glocks in the last year and a half, sold 5 out of the 7 guns already; with the other two in the "trade for something like a Smith" pile, and wrote a letter to the Glock big cheeses explaining my reaction to "their offer".
I had a bust case in one of my 1911 pistols many years ago (new ammo); some will say that their cases are not 100% supported either (they aren't) but the results were very different: ruined one magazine, cracked a grip panel, and browned my shorts. I mentioned it to a factory rep at a shot show-- he gave me 4 mags a set of Cocobola Grips off of a display gun, gave me a shooting bag, glasses, towel, stickers, and an APOLOGY (well; 10-12 of them).
Long story short-- Plastic lower receiver= junked gun-----Steel lower receiver= can shoot another mag full in a few minutes. (after you visit the lnumber 2 room)
Not long after all of this happened, a fellow club member blew his Model 21 up about 16 hours after it was at Glock to inspect, clean the gun and to replace the recoil spring to ready it for a GSSF shoot. Remaned ammo= no new gun. What a surprise ha
Oh yea, I joined this forum soon after this went down and have purchased 18 new and used Smith and Wesson guns in the same time period. I told the last Glock rep guy I saw (about a month ago) the last sentence with the remarks of: "I put my hard earned money into a product that backs there customers---NEW AMMO OR NOT!" (I had some Smiths before this, but was really a semi-auto competition type of guy, GSSF, IDPA, Steel, etc. but have gone more toward the wheel gun. There loss!