I discovered 10mm in the early 1990s when I had a Delta Elite. It was a fine pistol for its time. Since 2011 I have had 5 Glock 20s, both gen 3 and gen 4. I always loved the capability of the cartridge as an outdoorsman’s sidearm. In its full power loadings you basically have 357 mag ballistics with a bullet that’s 5 caliber sizes larger and a little heavier. Oh, and almost three times the capacity! So what happened?
I implicily trust my Glock 19, or 17 or 21. Not the 20, however. Out of all five Glock 20s I have owned, not one has been even close to being as reliable as my G19 (for example) with full power loads. Like most folks who have traveled the 10mm highway I tried an assortment of recoil spring combinations and magazine springs. None were more reliable than the rest. Occasionally I would get through a box of Underwood or Buffalo Bore without an issue and I would assume I had found the magic recoil spring weight. This was always followed by disappointment the next time I went shooting.
What about with watered down loads? The G20 was very reliable with the watered down loads that were basically 40s&w level. This is not acceptable.
There are those who say their G20 has been flawless. How can this be? They either got the exception to the rule, only shoot the low power stuff, have not shot enough, or are lying.
What do I think this is? I think Glock needs to reconsider the design around today’s modern full power ammo. It could be a great woodsman’s sidearm and many use it for that but in my experience with five (5) of them it’s simply not reliable enough. I have heard that the new G40 is more reliable and maybe one day I’ll try one but for now I’ll stick with 9mm with 45 being a distant 2nd as a woods sidearm. I have big bore revolvers, too, but those are boat anchors, slow to reload, deafeningly load, have limited capacity and must be kept cleaner to be reliable (think sand or dirt inside the trigger housing). Yes the revolver guys will go ballistic over this. Remember, I like revolvers, too.
Anyway, that’s why I gave up on the G20 (until Glock can make improve it).