Need advice - sell (and rebuy) Glock 20 or continue to troubleshoot ammo?

[t6t0]

Hello. I've owned a Glock 20 Gen 3 for a year or so, and I've pretty much always shot Underwood 180 grain TMJ ammo through it. It's the least expensive of the full power 10mm loadings and when DoubleTap and Buffalo Bore are 60% more expensive, it seems a logical choice. The problem is that this combination of gun and ammo has NEVER been reliable. At first, I thought that the gun needed a break in, then I thought that I'd just gotten a bad batch of ammo from Underwood (first, I was buying 200 grain TMJs which jammed, so I switched to 180 rain TMJs which seemed to feed better), but the more I shoot the gun, the more frustrated I become.

Today, I was getting failures to feed with both Underwood 180 grain TMJ and Underwood 180 grain JHP (XTP) ammo, both obviously from different production lots - multiple bullet nosedives or other kinds of failures to feed per mag, with multiple mags. I also shot 30 rounds of DoubleTap 200 grain WFNGC Hardcast, however, and didn't get a single malfunction. I've used stock barrel and recoil spring up until now, but today when the gun started to malfunction, I tried out my KKM Precision barrel, both with the standard recoil spring and a 20 lb recoil spring. I got the same kind of malfunctions with every combination I tried. To be clear, the last two times I shot the gun, I was using Underwood 180 grain TMJs, and the last time (when I remembered to bring my video camera to the range to record the malfunctions), I didn't get a single malfunction. The time before that, I got one failure to return to battery per mag. Very frustrating.

My question is, what do I give up on: the gun or the ammo? I'm looking at a couple courses of action:
1) Sell the gun and buy a new one (might try out a Gen 4 Glock 20) or a used one if I can find it for the right price - I will probably take a $150 loss on the deal, but from reports I've read, this could solve the problem.
2) Continue to troubleshoot the ammo, buy a calipers so I can measure cartridge OAL, contact Underwood if the ammo is out of spec, buy more DoubleTap ammo to see if I can feed that brand reliably - I will probably take a $150 loss in all the cost of ammo used purely for testing purposes and may not solve the problem.
3) I do not want to send the gun back to Glock. From what I've read, they don't even recommend using Underwood ammo, so they may not even be able to reproduce the problem at their factory. Add onto that, I'd have no 10mm handgun for multiple weeks in the summer when I do the most backpacking in bear country - NOT an option.
4) Something I haven't thought of?
5) Sell the Glock and buy a Sig P220 10mm instead. 

Thoughts?

[rw]

Did you buy it used? 
They do not make the regular frame gen 3 20 anymore, think they do still make the sf.
Find a glock armourer and get them to look at it, but i would just send it to glock myself.

[t6t0]

Did you buy it used? 
They do not make the regular frame gen 3 20 anymore, think they do still make the sf.
Find a glock armourer and get them to look at it, but i would just send it to glock myself.

It is the SF version, but I bought it more than a year ago in any case. What would a Glock armorer do, do you think? To my knowledge, they are mostly trained to disassemble the gun and swap out parts.

[rags901]

A few years ago, my son had a similar problem with a Glock 10MM and I convinced him to trade it on a new Glock .40.  Later, I regretted that decision when the gunsmith at the shop we traded with said it only needed a couple of new parts and was functioning fine.  He didn't say which parts, so I can be of no help there.

Is there a legit reason that Glock won't use Underwood?  I have no experience with them.

[Brian B.]

"3) I do not want to send the gun back to Glock. From what I've read, they don't even recommend using Underwood ammo, so they may not even be able to reproduce the problem at their factory. Add onto that, I'd have no 10mm handgun for multiple weeks in the summer when I do the most backpacking in bear country - NOT an option."

I dont know if this is true, i had not heard this myself,.. But the fact that you shot (only one other brand) DT with no issues combined with your above statement gives you a direction to go IMO.

[DM1906]

If you send it to Glock, they will test it with Blazer 180 gr. TMC ammo. It will shoot fine (for them), and they will return it to you. They do not endorse any ammo, other than major name-brand, such as Win, Fed, and Rem. Underwood is a boutique manufacturer, so not recognized by most (if not all) firearm mfg's. If you ask them, they will repeat what is in your owner's manual. BTW, Underwood and DoubleTap are NOT the same. Not even close.

[t6t0]

BTW, Underwood and DoubleTap are NOT the same. Not even close.

Would you please elaborate?

[Dave84]

UW is the hottest and may be slightly pushing what SOME Glocks can handle. DT until very recently has downloaded their ammo from advertised velocity. I believe some of Intercoolers recent testing has shown they are putting their numbers back up. Have you tried 22 pound recoil springs or anything? Maybe even just a new stock factory spring is needed. Old one might be all messed up, who knows? I've had issues with UW 180 gr in the past a couple of times but never any with the 165 grain. Give that a try. For bear country I would try both Underwood's hardcast loadings for reliability, if they fail buy Doubletap, even if it's not as hot. Best of luck. Let us know how things go.

[Dave84]

http://www.midwayusa.com/product/127997/federal-premium-vital-shok-ammunition-10mm-auto-180-grain-trophy-bonded-jacketed-soft-point-box-of-20
This would also be a great choice I think. Plenty powerful and safe to shoot in a Delta Elite.

[4949shooter]

My SF did not like then Underwood 180 grain load at all. It loves the 165 grain load from Underwood. I would suggest giving this load a try before you go through the hassle of selling it and getting another gun.

I have found the Gen 4 to be more forgiving of ammo selection. Others however, have not had the same experience.

[Intercooler]

Sell it! If it won't run what you like to shoot, get one that will... my motto 

[DM1906]

Yeah, what Dave84 said about DT. To this day, they are still well short of claims, or what they were years ago. Underwood will, normally, perform as advertised in like firearms.

[pacapcop]

My Gen 3 fullsize stock barrel did not like the 200 gr TMJ. All else from U/W works. Run a 22lb spring Wolff and steel guide rod. I also changed out mag springs with Wolffs +10%. I keep em loaded. But I  keep the nuke out. Just run the 165's and 180's mostly for social work.

[t6t0]

Thanks for the thoughts. Ultimately, I decided to prioritize ammo feeding. My Gen 3 Glock 20SF can't feed the ammo that I want to shoot, and has failed with several different versions of that ammo, so that gun is sold. I appreciate the feedback from people saying that their Glocks couldn't feed certain 180 grain loadings while the 165 grain ammo worked. However, this gun is for bear and moose protection, so I really bought it to shoot 180-220 grain bullets.

I've got a Gen 4 Glock 20 coming to my FFL this week, so I will be able to test a second gun with this particular Underwood 180 grain TMJ ammo. I will update this thread with what I find. If the second gun fails with the same boxes of ammo that were making my first gun fail, then I'll contact Underwood and try to figure something out. I know you can't return ammo, but I've got like 700 rounds of this stuff, and if a large quantity of it is out of spec, then surely they will want to make that right.

[4949shooter]

Good luck and congrats. I like my Gen 4 a lot. One thing I have found is that reliability with Underwood increased with the use of a 24 pound aftermarket RSA. I got it from Glockmeister, and it has been reliable with Underwood when the stock spring hasn't been.

I hope you won't need it though.