Glock 20 Gen 4

[PandaBear]

I took my Glock 20 Gen 4 out a few months ago and was having the slide lock back with 1 round left in the mag again.

10 round Gen 4 mag with Wolff 10% springs and 10mm3 follower.

I have installed the 10mm4 follower with factory spring and will test that out next.

[yakmaster60]

I don't mean to get off subject (which it really isn't), but this thing your doing, wanting to know about changing springs, and the adapter from Gen 4 to Gen 3 so you can use the stiffer springs, and the stronger steel guide rod, USED to be the way to go. It is NO MORE!!! Like one of the other readers on this thread, I used to HATE Glocks, and swore I would NEVER buy one. The only reason I ever got one, is 10mm.  I have been a 10mm fan since 1983, and other than getting to shot one in 1989 (Delta Elite Colt), I just never got around to it.
     As a mater of fact, shooting and guns had left my life for the better part of 18 years, and I just got back into it last year.  The first thing I did was go back to wanting the 10mm and MAN did I ever have a LOT to learn.
Anyway, as I found out the choices for 10mm are NOT MANY, and it seems that Glock was the only company that stuck it out in terms of development with 10mm. After 6 months of Research on the matter, in November of last year, I bought the G20 10mm Gen 4.  I am happy with the gun, but like most of you, I DONT WANT A 40 Short and week load in my 10mm. I found out about Underwood, and never looked back.
I have found, through my research, the ANSWER to the recoil problem, that just plain kicks the fire out of Glock store, and all the rest of the solutions offered called DPM Systems. They have the answer PERIOD!!! Go to http://www.dpmsystemsusa.com/ and solve the 10mm problem with the g20. They offer the Heavy Duty kit (I called Dmitri's, the owner of DPM) and I got three control rods (26, 28 and 30 Pounds) and SEVERAL springs to sort out the bullet grain/Powder loads.  I used Blue Machinist dye and marked the plastic part of the frame so I can SEE how hard each bullet I used marks the frame. I am SOO HAPPY, as it not only takes about 30% of the actual recoil OUT OF THE GUN USING THE 180 Grain Underwood loads, but you can tell that the slide BARELY touches frame (it takes much Testing, swapping and making a chart to record this info so you know WHAT ammo to use with what springs).
     This Triple Spring System is absolutely the Problem Solver to the G20 and using HARD AMMO, and not hurting the guns longevity.  I made a video on YouTube if you want to see how it works at:  https://www.youtube.com/watch?v=SD31pGGq4ig   
I hope this helps any of you, and I am going to Post this on the main topic page tonight as well, to share what I have learned and help any of you that have been using single springs to help this problem. Guys...IT WORKS!!!  It was the best $150.00 I ever spent on any automatic gun. Since then, I put it (DPM) in all my guns from my 1911 to my Walther P99 it worked so well.  Good luck, and if you have any questions you can reply to my new post I am about to put on the main page. Thanks...Thomas