Weaker 115 grain ammo plus brand new pistol (stiff spring) might cause problems. Blazer isn't particularly strong ammo either and on the weaker end of things.

I don’t know, but when chambering the PMC 115, the slide felt like it would momentarily “bind,” as if it wouldn’t go fully into battery for a moment, but then corrected itself.

Regarding the bind issue, I've had that happen with brand new Glocks. It doesn't actually cause a problem in operation (the slide will stay slightly out of battery before going fully in when chambering by hand), but does tend to go away on it's own after a hundred or so rounds.

 

I took a range trip today to put it through its paces. I brought along some PMC Blazer 115gr.

Break in means breaking in both the gun and the owner. How many total rounds did you fire? 500?

You already identified multiple possible reasons for the problem, now narrow it down:

New gun
new owner
not cleaned, lubed
weak ammo
works fine with another ammo
1st post

Don't hand cycle to replicate, only heightens the anxiety, and dangerous with live ammo.

 

Limp wristing? If you are new to Glocks I have seen cycling problems with this with new Glock shooters. Did you have any cycling problems at all with the 124? If you are new to Glocks and guns be careful with hand cycling your gun.

 

I always use 124 gr ammo for 9mm pistols.
More pop equals more reliable cycling.

 

Hey guys,

I recently purchased a brand new blue label. G34 gen 5 MOS. This is my first long slide Glock and I was pretty excited to pick it up.

I took a range trip today to put it through its paces. I brought along some PMC Blazer 115gr.

I had multiple failures to feed throughout shooting. Some mags would feed in their entirety, some would have 3-4 failures per mag.

A range buddy traded me a box of IMI 124gr and that ran fine. This may be u related, I don’t know, but when chambering the PMC 115, the slide felt like it would momentarily “bind,” as if it wouldn’t go fully into battery for a moment, but then corrected itself.

Curious, I experimented by attempting to recreate the failure to feed by riding the slide home slowly and was successful. Weird.

When I got home, I attempted to recreate the same feeding issue, but, of course now the rounds chambered fine. Go figure.

I’m not sure what to think about all this. The gun shot like a dream, and I’ve known and trusted many Glocks to work straight out of the box over the years. To me this is such an alien concept for a brand new Glock to have these issues.

Are G34s (and long slide models in general) finicky with light loads because of the greater slide mass?

One thing I am guilty of, however, if not cleaning / lubing my new Glocks before firing, but still have never had this issue.

Any words of wisdom are appreciated. Still pretty bummed about this!

thanks.

From Glock Armorer’s Manual

Observed Problem – Failure to feed

Probable Causes -

1. Underpowered ammunition
2. Shooting with an unlocked wrist
3. Weak recoil spring
4. Weak magazine spring
5. Dirty Chamber
6. Dirty magazine
7. Tight Extractor
8. Magazine not properly inserted
9. Deformed magazine (magazine sides or lips deformed)

These are not exclusive. At least a good place to start "trouble-shooting".

* Since the IMI 124gr ran fine - most likely #1 above.

 

I doubt the ammo or firearm had anything to do with it.

 

OP states he traded the 115 for 124's and stopped having issues.

That's a strong indicator of underpowered ammo compounded by a brand new Glock.

If it were a limp wrist, the problem would have persisted.

A range buddy traded me a box of IMI 124gr and that ran fine.

 

There needs to be adequate power for the gun to feed properly. You can demonstrate manually how much difference there is in slide position between where the top round strips from the mag and the fully rearward slide position.

Glocks are typically wildly over-sprung in OE form. Obviously spring energy is at highest when new, so the gun soaks up that much more power from weaker ammo. IIRC, the literature I've seen from Glock recommends 140 PF for normal function.

There's also a lot more friction in a new slide before it breaks in.

So I would say the malf's during firing are a combination of too much spring, not enough ammo power and not enough grip pressure. And the manual malf is primarily rail friction, which could have mostly worked itself out during the initial shooting/manipulation session.

One thing about stuff like this is you can have 100% function, but not know how close you are to slipping below it. So everything could be fine, but you're on the absolute ragged edge of 100%. Then there's one tiny change - temperature drop, manual impairment, slight change in ammo power, change in shooter focus, etc., and malf's creep in.

When I prove a gun, I try to figure out a way to over-prove it - a test run with heavier recoil spring, lighter FP spring, harder primers, FP bullets, lighter ammo etc. Definitely thoroughly test the gun with a much lighter than optimal freestyle grip. If it's close to the edge with your best grip, it's probably not going to run weak-hand - and almost certainly not going to run weak-hand when you come to a light round.

 

Hey guys,

Apologies for the late reply.

Definitely not a limp wristing issue. I've owned many handguns, mostly Glocks for 15 years from 9mm to 10mm. I've never had such an issue with any 9mm Glock. While I'm no competitive shooter my grip is solid.

I agree, it's most likely ammo related. Btw, I realized I misspoke and created a new type of ammo "PMC Blazer." Silly me. The ammo that was failing is PMC Bronze 115gr. I'm used to shooting the cheap stuff. Btw, I've never had this issue through my G26, G19, G23, or G45. My CZ P07 had not one issue with this ammo during said range trip and I've never had this issue previously with PMC.

I'm fully aware that the heavier slide, underpowered ammo, possibly stiff RSA may contribute to this, but my small amount of research into others with similar issues seem to amount to few and far between cases, even with the G34.

I guess my initial post was to determine if anyone has had similar issues with the 34 and underpowered ammo. I spoke with Glock and they were very brief "yeah just shoot more 124gr through it." Lol. I guess Glocks aren't perfect after all, but this will be my home defense gun so I want to make sure it's going to function reliably.

More testing to be done!

 

After several hundred rounds are shot through the gun, you may find the PMC will function.

 

I bought 2 Glock 34 Gen 3s two years ago and actually broke them in with Blazer Brass and PMC Bronze 115g ammo. I had no issues with G34 #1, but on the second one I had a few FTFd issues but after a hundred rounds or so the problem went away.
Give it some time. Break it in.
Congratulations, by the way. 😎

 

If you are going to shoot more light loads through it. You might want to clean and lube it. Then lock the slide back for a while to release a bit of spring tension. But Id just get 200 rounds of ammo thats on the more powerful end of the scale. Unlike on the light side of the powe factor.

 

How does the G34 run now?

 

I don’t think the “discussion starter” is with any longer. “With us” as in they started a thread. Replied once then left, never to return.
My guess is they answered their own question by continuing to shoot and break in their new toy.

Screenshot:

 

I really dont think you have anything to worry about. A Gen 5 34 is a very sound gun they are very nice guns. As long as youve put some rounds thru it (300 or so) . And it works with that you can move on to testing self defense ammo. I would always want to make sure my gun works with whatever hollow point ammo I chose. I start out with one magazine and once thats good after 500 or so rounds move to more magazines. ANY gun could be a dud and not work. Even guns that are supposedly reliable my not be from the get go. It may need a break in.

 

I guess that’s my issue, I’ve never had to break in a Glock or Sig, not sure the benefits would outweigh the negatives on that. I wanted to replace my G45 with the G34 as a duty pistol but it seems to be a step down fir that purpose.

 

A G34.5 is definitely not a step down from a G45. A G45 is a duty gun. A G34.5 is the practical/tactical model. A competion model. The 34.5 would clearly be a more accurate gun. And easier to shoot. Its got the lighter trigger pull, unless you buy the blue label model. The blue label has the standard trigger pull and the fixed rear sight. I would be very confident using mine as Home Defense pistol, but with 19x plus 2 mags.

 

It is in reliability if it’s needs a break in period and still may not cycle lighter loads. My 1911 overall is probably better than any polymer firearm but due to its possible reliability issues, it’s not replacing the G45 as a tool.

 

Do you shooters clean and lube your pistols when new before shooting as you should?

 

Yep, I actually read the manual and follow its recommendations. 😮
😎

 

I stay away from 115 gr ammo and I could definitely see why a brand new long slide gun would not cycle well with it.

 

Maxx702 makes a strong point dont use 115 grain loads for the first couple hundred rounds.
Cleaning the pistol is mentioned. I always clean new or used guns 3 times before useage. Lubing them properly too before the first range trip. I als dry fire too, tontry and break in the trigger.