Holy crap!  I can't watch the video right now...was that my ammo or something different from Underwood?

Also, I just noticed...the thread title and OP have a type in them.  The stuff I sent isn't the Xtreme Penetrator, it's the Xtreme Defender.  The XP is 140gr, the XD is 115gr (at least at the time of this posting).

And now we know!  Thanks Tic-Glock!

Thanks for doing the pulldown!  Second on the wondering if this was loaded at the last one that was pulled down, if it'd hit advertised velocity.

I haven't paid that close attention, but my perception was that out of the 4.75" barrel he always uses for testing, doesnt the average for the Underwood rounds tested always hit advertised velocity?  If not it's not a massive deal, I just sorta always got used to seeing people Chrono and get advertised velocity.

I think that would be a departure from what they normally use to dictate their box speeds.  Memory serves it was either a Glock 20 (4.6" barrel in those) or a 5" 1911-type they used.  If they're basing their numbers off 6" barrel now then that is something new I believe.

Underwoods rep though is that they meet what's on the box (and in many cases exceed it).  If these are hitting those speeds then IMHO, they shouldn't say 1700 on the box.  If the 4.75 average is 1640 then 1650 would be a more appropriate number.

Thanks for testing these out for us All!  Man had I known you were going to share the Post-It I'd have written a little neater! Bah, who am I kidding...that's about as neat as this computer geek can write haha...

I used think the only EDIT: slide difference between Gen3SF and Gen4 G20 was the new dual RSA of the Gen4, however that is NOT true.  I stated as much in a previous thread a long while ago here now and someone posted a link to either a website or PDF that listed the differences - it wasn't just the RSA.

Had to send my Gen4 G20 to Glock under warranty due to FTF with real power and up 10mm ammo, noted this on form when sending in.

Got back pistol with a "No Issues Found" note.  Traded e-mails, come to find out, they fired "20 mags worth" of Blazer 200gr through it...essentially the opposite of what I stated the pistol was malfunctioning with.  Essentially they sent an unreliable firearm back to their customer, and when realizing this, didn't offer to pay for shipping back to them so they could correct their mistake.

When I found out new followers were out, I had #3 and now #4 was out, I asked Glock first on their web form, then calling in explaining I'd wait 2-3 months after filling out web form and no followers, and then again after waiting a month or three I used the web form.  In all three cases, no #4 followers to try and correct the FTF issue, no contact from Glock.

In short:  Glock will turn your pistol around quickly.  Whether they'll fix it or not, who knows...certainly cannot trust it's Glock Perfection.  Vastly underwhelmed by their Customer Support, especially given their slogan.

Personally I'd like to see the Underwood 115gr Extreme Defenders.  Going to do a Underwood buy tonight actually, Intercooler how many do you need to do a video?

Quote from: Roguer on September 10 2016 08:38:45 PM MDT
So...what is the main recommendation?

Gen 3 Glock 20 less problematic than a Gen 4 glock 20?

What about later Gen4 glock 20 production?

And would the Glock 40 have the same Gen 4 problems?

There are no changes in Gen4 G20 production that makes them differ from early Gen4 G20 production save for the #4 follower.  I'm fairly certain someone with Gen4 G20 issue obtained #4 follower and it didn't fix their problem.  Glock themselves was unable to fix Gen4 G20 issues, instead replacing customers firearms who insisted with Gen3SF.  So make of all that what you will in regards to Gen4 G20.

Don't know about G40...

Quote from: DM1906 on September 02 2016 10:10:50 AM MDT
Unless you are using Gen3 springs in a Gen4 pistol, the Gen's don't compare. Using a 24# spring is a stretch. The factory RSA is only 17#. A true 20# spring is usually all that's needed for maximum loads, while still able to reliably cycle light loads. If you upgrade the RSA, shoot a mag or two of .40SW. If they all cycle, then it will cycle all the 10mm offerings. If you use a 24# spring and it cycles "light" loads or .40's, it isn't a 24# spring. A true 22# spring won't reliably cycle lightweights. This personally verified with thousands of rounds and weight-measured RSA's, 14-26# evens. 24-26# springs are essentially useless for 10mm (but handy for .40/.45S and .460R).

Thanks DM1906!  Unimakpass, there's your answer...

Quote from: Unimakpass on September 01 2016 01:51:26 PM MDT
Chuck, was thinking of spring change in gen3. If one goes with the heavier spring will it work with the lighter rounds? I see some have 3 different spring weights.

Let me preface this with, I'm a very casual shooter, don't own a pre-Gen4 10mm or have ever owned one, and am not a gunsmith.

From what I was reading of the pre-Gen4 G20's, some people could switch to say a 24 lb recoil spring and still shoot weak 10mm (say, Blazer), some couldn't.  I think what you'd have to do there is test it out.  The nice thing is most aren't looking to switch recoil spring and then carry with really weak ammo, they use that at the range.  So you can do the recoil spring switch, shoot the cheap weak ammo at the range, and if it doesn't work, either decide to live with the unreliability, or, go back down a little to something like 22 lb.

I believe I also read though if you switch to a higher poundage recoil spring, the felt recoil increases.  Not massively, but that was the trend I remember reading.

I honestly don't know if a spring change is even needed for Gen4.  I could have sworn I'd read that the Gen4 RSA has a higher poundage than the pre-Gen4 RSA...or at least remember reading someone commenting on that.  I'd be interested to see if that is indeed true or not...I think there's an assumption out there that the Gen4 RSA is the same poundage (17 is what I believe pre-Gen4 is) as the pre-Gen4.  I'm not SURE that assumption is correct.

I can't say if my issues have been resolved or not.  I ordered - from Glock (who after 3 requests never bothered to send me the #4 followers I asked for to solve the FTF issue) a new RSA, new mag springs, and new #4 followers (the latest at this time).  I also when I took my mags apart tried to determine if they were hanging up anywhere, and thought that where the metal insert in them has the injection molded plastic coming through might be a little rough, so I filed that down, and at the top of the mag where the metal insert ends, I filed that some down also.

Since I only had 100 rds of the PBR ammo left, I went ahead and shot that with my new stuff and filed mags, and, I can report that I didn't have a single FTF, whereas before there would have been several FTF; I used all three mags shooting the 100 rds.

I have such little time to shoot, I haven't even bothered ordering more PBR - but I will I guess, I want to see if the FTF is fixed, and then, start adding the old components back in one at a time and see if I can reproduce the FTF consistently...it'd be nice to know where the issue was, maybe it'd help someone else.

As for is the issue solved?  I can't say.  If you get a 'first stock' G20 Gen4 like I have, will you have issues?  If you get a new stock (to my knowledge, there have been zero revisions to Gen4 G20 so they'd all be the same, save for at whatever point, they start shipping with #4 followers), will you have issues?  My suggestion would be to get 400 rds of the ammo you're going to depend on and make sure to shoot at least a couple hundred rounds of it to make sure you don't end up with Glock Perfection like I (and others) did.  Unfortunately, when it's your life you're depending on, you can't just assume Glock Perfection...there's no way I'd do that with a Gen4 G20.  I second the KKM barrel though, zero complaints with mine.