Problems with failures to feed with Underwood Ammo, Gen 4 Glock 20

[DAVIDF]

The_Shadow, yes very well could be. I'm speculating too as I am no gunsmith. I question the design of the follower as it is different than my other Glocks & can bind easier.

I just read 2 posts on different forums. In 1 of them, someone was having FTF with their Glock 20 Gen 3 with hot loads where the nose of the bullet would get lodged against the top of the barrel hood. Someone chimed in that he had the same problem, replaced the magazine follower & the issue was resolved.

On another posting, someone had an issue with 2 of their 3  Glock 20 Gen 4 magazines locking the slide back while there was a 1 round still in the magazine. Someone else added that they had the same problem with the magazines in their Glock 20 Gen 4.

More questions to ask Glock tomorrow!

[4949shooter]

I will be interested to hear what Glock has to say about this. It really seems to be a "gun specific" problem.

There was a thread on Glocktalk in the 10mm forum around two years ago where the OP's Gen 3 20SF exhibited the same or similar issues. He ended up trading it in to Glock for a G19 because the problem was never rectified. His may have been worse than yours though.

Good luck!

[DAVIDF]

Just talked to a Glock rep.  As soon as I described what is going on he said he will send me a new recoil spring & suggested that I send him my 3 magazines to be replaced. Start with this & see if it fixes the issue.

Also asked him about the trigger connector being different than both the connectors in Glock 17 (5.5lb connector) & Glock 34 (4.5lb connector). He said it is a 5lb connector. First person I've been able to talk to who knew there is a difference. I like the connector a lot, much better than the 4.5 lb connectors that I have installed in my 17 & 26. I'll see if I can find them anywhere to order.

Thanks to everyone for your help. Once I receive the new magazines & spring I'll let you know how it works. Hopefully, that is all that is wrong.

[RMM]

I guess that you're talking about the "." (dot) connector.  It is indeed in between the normal and "-" connector.  My Gen4 G17 also has one and it is nice, a slightly lighter trigger without feeling "mushy" like the "-".   You can only order one right now if you have a serial number from a gun that was mfg. with the connector (i.e. Gen4). 

[DAVIDF]

Yes, he referred to it as dot connector. My 17 & 26 are Gen 4's, but don't have the same connector.

[RMM]

You should be able to get some dot connectors for them then.  You must have "earlier" Gen4 guns... the initial Gen4s came with the regular connector but Glock later switched them to the dot connector.  The Gen4 with a standard connector is ~1lb. heavier than a Gen3 with the same connector due to the difference in angle of the connector (which is due to the narrower trigger housing due to the change in backstrap). The "dot" connector puts them back closer to the same pull weight as a Gen3. 

[orangeride]

Hey guys, just found this site. I've been over at glock talk for a few years now. My 20sf has at least 20k through it since I got it 3 years ago. I've shot boat loads of nosler 135's at 1500fps and lots of 200gr BT hard cast at 1230fps. The gun never gives me problems with the stock RSA. I while back I was having some feeding problems with 155gr SWC in a .40 conv, I upgraded to some wolf +10 mag springs and all was good. So I thought. I went back to my 200gr BT and started getting nose up Jams like your getting. I went back to new stock new mag springs and they ran perfect. The funny thing is the wolfs run good with all my other loads. When you start running max Sami spec loads the springs have to be matched almost perfect. That's why when you went with the heavier RSA things got worse. If its a pretty easy to feed profile I'd say your mag springs might be a little soft, new oem or wolfs might fix it. 

[REDLINE]

Welcome orangeride!  Thanks for the great info and tips.

[DAVIDF]

I have an update on the Glock 20 Gen 4. Glock sent me a Gen 3 recoil spring assembly in error. I called them & they sent me a Gen 4 RSA. Fortunately, I have an adapter to use the Gen 3 RSA in my Gen 4 gun. I also received new magazines from Glock. They are also Gen 3 mags, but I figured I would at least give them a try since I'm right handed & would probably never switch the mag release to the right side anyways. I numbered all of the magazines & I purchased an additional Gen 4 magazine.

Went to the range today & tried all of the mags & 3 of the 4 RSA's that I have (new Gen 4, new Gen 3, & Glockstore Tungsten Gen 3 type w/23lb springs). Tried the new Gen 4 RSA first with American Eagle 180gr FMJ. With 1 round in the magazine the slide locked back with 1 of the Gen 3 mags. This was the only time this occurred with any of the magazines. No other issues with the Gen 4 RSA with American Eagle, PMC 170 gr jhp, Underwood Delta Lite 180 gr fmj, Underwood 180 gr TMJ, nor PBR 165 gr fmj. However, with PBR 200 gr FMJ I was having ftf's constantly. The nose of the bullet was consistently lodging against the hood of barrel.

I then tried the Tungsten guide rod w/23lb spring with the PBR 200 gr. Same results. I then tried the Gen 3 rsa. Functioned perfectly with the PBR 200 gr. No ftf or any other issues.

The Gen 3 rsa as well as the Tungsten guide rod w/23lb spring worked perfectly with the Underwood 180 gr TMJ.

It appears that the Gen 3 spring works best with my gun. Now at this point, I am considering calling Glock, letting them know what I am experiencing, & asking if they would exchange my Gen 4 for a Gen 3.

[DAVIDF]

Also, I wanted to add that thanks to all of your help I am better educated on Glock trigger connectors. I examined the trigger connector on the Glock 20 as well as the ones that came on my 17 & 26. The "." connectors came on the 17 & 26. However, the standard unmarked 5.5lb connector came on my Glock 20 gen 4. The Glock rep said that it would have the "." connector. I've installed the "." connector & the "-" connector that I now have on my 26 & 17, but the original 5.5lb connector feels the most crisp. The "." connector is horrible on this gun.

[REDLINE]

Amazing how a minor tweak here or there can mean the difference between 100% success and utter failure.  I hope they give ya the Gen 3.

[4949shooter]

Amazing how a minor tweak here or there can mean the difference between 100% success and utter failure.  I hope they give ya the Gen 3.

+1 

[Intercooler]

I need a Cliff Notes on Glock terms 

[REDLINE]

LOL.  I feel the same way when you guys are throwing around Witness and 1911 terminology half the time.

[sqlbullet]

That is why I limit my technical jargon to do-hickey and thing-a-ma-bob.