Underwood Ammo: Possible Hard Primers or is it Me?

[DM1906]

Very good points!

   What would allow that much travel off-center? I'm not real up on striker-fired pistols and can't picture how the firing pin could go through the opening being that far off.

It can't, unless it's broken.

[DM1906]

Might not be the firing pin not centered in the channel.  It could be the barrel not seating quite fully into battery.  This would cause off-center high strikes.  Or an out-of-spec barrel might center the bore too high in the breech, resulting in off-center low strikes.

Any of these conditions indicate a broken pistol.

If the FP safety is failed, and somehow does allow the striker to fall if it's out of battery enough to allow the chamber low enough to make that strike, the trigger shouldn't engage the striker lug (it will cam out of position = dead trigger). A defective locking block or barrel lug can allow the condition, but I think it would be more frequent, and should be visually obvious. Unless the barrel or slide is WAY out of spec (and visually obvious), the barrel can't position too high in the slide. Unlike 1911-type pistols, the slide does not secure the barrel. Glock pistol barrel (lugs) determine the state of battery proportionate to the slide position (barrel lug and locking block engagement). If not for the barrel lugs (and slide lock), the slide and barrel would just launch off the frame at the first chambering. This is also possible on a healthy pistol, if the slide lock is damaged or installed backwards.

Glock OEM striker and striker channel have a very tight tolerance. A failure here would much more likely prevent a strike, rather than allow an off-center strike. The firing pin is flat, and tapered. If the spring cups did allow the striker to misalign, the shape of the FP would center it well before it extended enough to cause a primer strike. The striker travels and centers perfectly, even with the spring cups completely removed (just tried it). However, there's no way it would fire, as the striker has no spring-tension in this condition. Ultimately, if any condition allows the FP to strike off-center at any time, the slide is probably irreparably damaged/defective. Otherwise, this condition would exist much more often than not, and I seriously doubt it would survive many firings, let alone a couple hundred.

[Johnny Gunz]

I appreciate all the responses and assistance gents.  I performed a pretty detailed exam and everything in the pistol appears perfect.  The FP is undamaged and centered, but seems to leave a slightly deeper indentation on one side of a strike.  The 9 mm cases we looked at fired from Glocks  seemed to have a similar strike.  All I can do is watch it and be mindful of the suggestions given here.

I've been a lurker, but joined up for some help.  That's exactly what I got and it's appreciated.  I have to say I'm really glad I finally got into the 10 mm club.  I shoot Glocks regularly, but didn't have one I felt was fit for critter protection.  I have a beautiful Dave Clements custom Redhawk, but shooting it is not instinctive anymore after constant Glock use (and it weighs almost 50 oz. before being stuffed with 320 grain slugs ).  The G29 solved this problem very well.  I must also give props to the Lone Wolf .40 conversion barrel.  It shoots great, and easy, and makes the Glock 10 mm's just about the most versatile handgun around.

I'll keep y'all posted if anything developments with the ammo.  Until then, I do think the UW 180 TMJ is an ideal woods round and is nice shooting, considering the power, in even the G29.  Take care and thanks again everyone.

[Johnny Gunz]

BTW, I changed the title to sound less critical of UW.  The price, fast shipping, over quality, accuracy, and variety of the rounds is awesome.  I do not wish to malign the company as it has a long and solid reputation among 10 mm shooters.  Besides, this issue could be me or the gun, and maybe just a break in thing.  Who knows, but I'm giving UW the benefit of the doubt at this point.  And if an occasional hard primer does slip in, it's no different than any big name ammo company anyway.  Be safe.

[DM1906]

You, as a Glock armorer, should be at least familiar with the designed function of Glock pistols and their various safeties. The off-center primer strikes you've experienced, more than once, renders that pistol unreliable, regardless of how it appears or functions now. It isn't a "break-in thing", nor is it the ammo. At least 2 internal failures had to have occurred for that to happen, and it will happen again. Just hope it isn't at a time someone's life depends on it.

As far as suspecting "hard" primers, I don't buy that. Primer lots can be bad, but not because they are "hard". When I do custom work on any trigger or striker, it gets a full test with rifle primers. Stock pistols don't see any difference whatsoever, and only the lightest striker springs have had an issue.

[Dave84]

I like Underwood as much as the next guy but have had hard primers in the past as well. It's not some phantom thing that does not exist. It was their 180 grain target load about 2 years ago. Just would never run very well. Also, the 147 grain +p+ 9mm didn't feed in my Glock 17 or PPQ. Factory recoil spring not up to the task? Anyway I bought their +p version after and that runs fine.

[4949shooter]

Thanks for the honest assessment, Dave.

No ammo company is beyond reproach.

[DarnSkippy]

It's not just you, Senor Gunz.  I have had primers fail to ignite on 10mm Underwood 180gr TMJ, 180gr XTP, and 220gr HC.  Sometimes a second strike lit them, sometimes not.  On one box of 50 Underwood 220gr HC I had 6 failures to fire.  I have had no failures at all with Hornady, Remington, Double Tap, or Precision One 10mm.

I want to love Underwood 10mm but I need to decide if a slower, more expensive round from Double Tap or Buffalo Bore is worth it to know that first round will go off when intended, under duress.  It's ironic because I've never had feeding issues with Underwood, just bad primers.  And I keep the firing pin channel scrupulously clean and dry on my G20.  Stock striker spring, too.