Glock 20 SF

[mt10mm]

Its been no secret the problems I have had with the 4th gen Glock 20. Today I ordered a new glock 20 SF and will see if I have the issues. I have the 22lbs recoil spring and ss rod already. Is there anything else that's a need to have for the 3rd gen g20?

[Rich10]

I have not had poblems with my Gen3 20sf.

[mt10mm]

My gen4 was a train wreck, I hope the SF is better.

[4949shooter]

Its been no secret the problems I have had with the 4th gen Glock 20. Today I ordered a new glock 20 SF and will see if I have the issues. I have the 22lbs recoil spring and ss rod already. Is there anything else that's a need to have for the 3rd gen g20?

Yep.....you need some ammo! 

I have said this before but I will say gain that my SF functions great with the Underwood 165 grain tmj, utilizing a 22 pound captured RSA I got from Glockstore. I haven't tried the 180 grain stuff from UW with this RSA, but it didn't function well with lighter springs. Others have had problems with the UW 180 grain tmj, so I am wondering if there I a QC issue with that particular round.

I have also mentioned this before, I keep a really tight wristlock when I shoot. I believe the heavier RSA is needed to prevent the slide from battering the polymer frame when firing the heavy duty ammo, like Underwood. The gun works fine with the lighter stuff (PMC 200, CCI 200, Federal and Remington 180) with the stock RSA. As a side noted, I have fired hundreds of Underwood 200 grain XTP with one hand with the stock RSA without issue, which gives more credence to my theory of frame battering with a two hand hold (my opinion). Firing one handed the gun recoils up more instead of back, which I believe dissipates some of the recoil and takes the stress off the frame. Again, just my opinion and my experience.

Good luck with your Gen 3 SF!

[The_Shadow]

It will take a high speed video capture (1000 frames per second or faster) to be able to see exactly why this issue is so prevalent in the Glock Gen 4 and even others, while utilizing the higher impulse ammo like the Underwood.  By playing the video back at slower frame rates it may show where the problem is, and/or what happening.

It could be the slide is unlocking too early with the higher impulse ammo...
It could just be the slide speeds are too great with the higher impulse ammo...
The case of the fired round maybe holding too tight to the chamber walls disrupting the timing for ejection...
It could be the frame is flexing...
Magazine lips being spread or out of alignment, may allow ammo to feed incorrectly...
Could be a combination of things, to include limp wristing/grip/control during the recoil phase...
Is the brass case too soft?...Allowing too much expansion for the pressure developed? 

The problems are not just glock guns either, and setups of each type gun are different for the tuning of the cycle.

The very few issues I have seen testing from the S&W1006 w/ the 22lb recoil spring, were the UW 220 HC where it failed to extract from the chamber, the extractor jumped over the case rim while trying to cycle, leaving the casing inside the chamber.  The other was the UW 135 JHP, it tested at 1700 fps, blew the primer out, also cycled leaving the casing inside the chamber.  I didn't get to test using the 24lb spring, so don't know if it would hold longer till pressures dropped to more reasonable levels.  I didn't have the G-20 SF back when I tested those, and still haven't decided on which RSA I want to get, although I am leaning toward the Wolff Gun Springs steel non captive rod and an assortment of spring weights, 20lb, 22lb, 24lb to tune for the higher impulse ammo.

One thing as a handloader, I can adjust the ammo's potential to suit my setup or particular needs!   I can sacrifice some speed for reliability!

[mt10mm]

Picked up my SF today and installed my 22lbs RSA I had bought for the gen4. Can't wait to test all the different ammo I have. Going to start with UW 220.

[Dave84]

That 220 will probably leave you upset. I've shot all the different grains and that was the least reliable for me. Hope it works great for you and maybe my Glock needs some work.

[mt10mm]

That 220 will probably leave you upset. I've shot all the different grains and that was the least reliable for me. Hope it works great for you and maybe my Glock needs some work.

It gave me the most trouble with my gen4 but hoping this SF likes it.

[The_Shadow]

The 220's gave many people trouble in several different guns!  Getting it to run was mostly because of the WFN and timing and tuning of the guns!  If you can't get it to run right don't beat yourself up over it.

The ejection of the fired case and the angle of feeding, as the cartridge tries to stab itself into the chamber, in relation to the slide speed can a challenge.

Please read through this info and you will get an idea of what can happen...This document is well written and explains in detail what happens in the cycle of the cartridges. http://38super.net/Pages/Overall%20Length.html

Magazines for the Glock can be an issue in itself as the feed lips are wide, as the cartridge is sliding forward, it can get knocked off course by a delayed ejection of the previous round not exiting out of its way fast enough.

[fanninland]

Thanks for sharing the link Shadow, that is some very informative reading that will help explain some things to me. 

[The_Shadow]

fanninland, You're welcome!  As a handloader, I like to study things...I can make adjustments for the ammo I use.  Those who buy from the commercial establishments are at the mercy of what's being sold.

We all want the most bang for our money, but when things like too much impulse/pressure, bullets seated too long for your setup, then you can get frustrated, that and Glock's new 4th generation setup being able to deal with these things can drive  people over the edge...Therefore, Given the nose profiles and seating depths as it relates to a particular gun setup and the impulse of the cartridge issues are being seen.   

Sometimes we expect too much!   

[Rich10]

That 220 will probably leave you upset. I've shot all the different grains and that was the least reliable for me. Hope it works great for you and maybe my Glock needs some work.

It gave me the most trouble with my gen4 but hoping this SF likes it.

I don't know, man.  I haven't even bothered with the UW220 in mine, yet..... 

[4949shooter]

From what I have seen so far, the Buffalo Bore 220 has been working okay in the Glocks. It's expensive, but it might be worth running a box or 3 through your gun to determine functionality. Then after that it's just a carry round so you won't need to buy and shoot too much of it.

[mt10mm]

The buffalo bore ammo is expensive but if runs good it is an ok trade off to me.

[4949shooter]

I agree. I think I might end up going the same route. Not unless PBR can come up with something that works for a better price.