Advanced Armorer class notes

[Flexmoney]

The report below is copy and pasted (with permission).

I was fortunate this week to have the opportunity to attend Glock's "Advanced Armorer" class and it was more than worth the two day investment and trip to Smyrna. If anyone who already has their armorer cert has the chance and the interest, this is a very well done program. The last day is a diagnosis and repair exercise unlike any I have experienced. We were presented with 18 different guns of every variety with anywhere from 4-7 distinct problems in each gun that were purposely staged and known to the instructors (and one perfect gun in the mix). The exercise was supposed to represent the full range of real world issues their customer service group sees in an average year. You had to work each gun until you had every problem and the fix 100%. The coaching was excellent and the experience probably compressed what would be 20 years of field armorer experience into a single day.

Anyhow, a few notes gleaned from what I learned.

1. Glock has renamed the old 3.5# connector as the "4.5#" connector to reflect what it really does to a trigger, but physically it is the same unit. It is still a restricted item. Meaning that unless you work for an LE agency you have to get them from other sources.

2. Glock will often enourage their users who have some sort of Kaboom or case head blow out, etc. to go directly to HP White Laboratory with the gun and the ammo and get a third party evaluation of what happened. If you go by the numbers these incidents are extremely rare considering how many Glocks are out there but they get a lot of publicity. The reason they want end users to go this route, it is an unbiased third party, unlike them or the ammo manufacturer, and the cause of these gun blow ups almost always turns out to be ammo related and they are exhonerated in almost every case. The HP White lab people can do failure analysis of the remains of the gun and make a fairly accurate determination of what the pressure was achieved in the incident. Turns out all of these "kabooms" are instances where they find pressures in excess of 75Kpsi (as opposed to the 38Kpsi ceiling allowed for ammo and the 50kpsi proof load Glock uses) in almost every instance. That is of course an ammo problem, caused by setback, overcharge, powder contamination, etc.

3 Glock is training LE instructors now, while I cannot get into that course, the instructor did share a few things that are different from what you might encounter in a standard gun course. The one I found most interesting was their immediate action drill for clearing a double feed. It goes something like this:

a. Yank the magazine out and down and clear of the magwell

b. Re-insert it immediately

c. Then rack the slide

What they have found, is that no matter what the nature of the double feed, when a Glock mag comes out, what ever needs to fall out will fall out before you rack the slide, saving time on this drill Vs the traditional way of clearing a double feed. The instructor believes this is a key advantage they have over other guns since this drill will not reliably and consistently work wtih other designs.

I have not had a lot of time to play with this but I plan to do so. In the half dozen times when I was allowed to stage the double feed with dummy rounds and handed it back to the instructor, the process worked every time, no matter how I staged it...they have something here.

Another interesting drill. The instructor removes the trigger return spring from all guns and the students shoot a few full evolutions that way. Not only does it re-inforce the drill for keeping the gun running if your spring breaks, it forces students to adopt the trigger control paradigm Glock teaches (trigger is held to the rear while the gun cycles and then allowed to go forward past reset) or the students are doing tap rack drills for every single shot....I can see how that will force you to get with the program on trigger control or follow through really fast! They say it is very successful.

4. It is still important to put the right firing pin in the right caliber gun but the firing pin markings have been changed. Instead of the old markings:

9mm=no markings

40/357= 40 or the number 4270 on the back surface

45/10mm=marked 4557 on the back surface

the new markings are a series of bars on the head of the firing pin just in front of the place the spring cups reside, these bars are

9mm=one bar

40/35745gap=two bars

45/10mm=three bars

5. For certified armorers, there is a new parts list available that is far and away the best one they have ever produced because it includes notes about identifying marks on parts. The list is FRM-72-26/Rev 8/09.11.08 and if you are an armorer, you need it. Glock has acknowledged that all the minor changes done in the last 5 years to the small parts is making the task of being an armorer more complex than ever, but this new parts list is a good first step to clearing things up. Some things are so complex and serial number specific that they need to be managed by a database, and their own factory armorers and repair people have to go to a terminal and look things up. Some examples:

-There are a total of 22 different locking block variants out there

-There are a total of 9 different slide stops out there

6. Scheduled replacement of parts. The parts that most commonly fail are some that high volume ammo users (those of us who "shoot our f*#king guns") should plan to replace as part of a maintenance schedule. Here is the list I was given:

-Springs

Recoil spring is the one that goes fastest, recommend replacement of the recoil spring assembly every 3-5K rounds for 9mm and every 2-3K rounds for other calibers. Officially you are o.k. if it passes the armorer recoil spring test, with an empty gun, cycle the slide, in a vertical position cycle the trigger and hold it to the rear, now pull back the slide and easy it forward VERY gently until it stops. Repeat several times. If yours stopped ever so slightly out of battery you need a new recoil spring.

Other springs are not on any sort of set schedule, but certainly the striker (firing pin) spring can go bad at some point over the years if you are shooting a lot. The coil type trigger return spring can break unannounced, although the hole in the back of trigger bars where it engages has been enlarged by 3X over previous versions and this seems to have dramatically reduced the incidence of this happening.

-Extractors

-Firing pin

-Firing pin safety & spring

-Magazine followers

-Magazine bodies

One thing of note here, again for high ammo volume guns. On every single cycle (including dry fire), the firing pin and the firing pin safety do make contact and the impact turns the firing pin safety a bit. Eventually both are going to wear out from this contact alone, although it may take 100K rounds or more. the failure mode is not that the gun stops running, but that the FP safety will faill a push past test, meaning it no longer has the abilty to always arrest the firing pin in it's locked state. You should inspect both of these parts for wear if you shoot or dry fire a lot and try the push past test once in a while. Basically with the slide removed, push the firing pin to the rear and ease it forward until the firing pin safety stops it. Now try and push it past the fp safety wtih pressure. If it pushes past, it failed, if it does not, the FP safety is working.

7. Glock makes 3 sizes of magazine spring, 9,10, and 11 coils. If you are running a full size gun with anything out on the rails (lights, lasers, etc.) you should upgrade all of your magazines to the 11 coil spring if they don't already have them. No recommendation for upgrade or change on other guns. The .40 caliber guns have been the biggest problem with this issue. Any time you put anything out on the rails of the gun you have changed slide velocity, period. And the timing of the magazines is such that they have to keep up with that change. A 10 coil spring in a G22 magazine will not allow that magazine to consistently keep up with a G22 that has stuff mounted on the rails, period. If you have a 17/22/31/34/35/17L/24 it is not a bad idea just to upgrade all your magazines to the 11 coil spring. If you have stuff on your dust cover rail, it is also important to keep your recoil springs fresh. You also just need to test the entire rig live fire with your set up and your chosen ammo until you are certain it is going to run reliably, 200 rounds recommended. You should be able to run 100%, but if stovepipes or fte's happen it is a warning sign.

There are some gadgets being made that are simply too heavy to be put on the dust cover rails of a Glock and allow it to retain the slide velocity profile it needs to run. The simple lights or lasers from Insight, Surefire, Glock, etc are usually not the culprits, but heavier devices or side mount devices are often the culprits and in some cases there is no way to mitigate the way they change the dynamic mass balance equation for the gun....

8. Finally, on the subject of dry fire. Glock as admitted that the breech face wall is thin enough to be damaged with extremely high volumes of dry fire (e.g. hundreds of thousands of dry snaps per year. they strongly recommend good snap caps with artificial primers that will arrest and dampen the impact of the head of the firing pin if you are going to do high volumes of dry fire. A gun that appears on their door step with a cracked breach face will be repaired without question at this point, but it is an acknowledged failure mode caused primarily by high volume dry fire. Use a snap cap or other device that arrests and or damps the forward travel of the firng pin and impact of the striker body on the back of the breach face.

I may tack a few more comments in the future as I review some of this, but those are the highlights from my class notes. Hopefully some of that was helpful.

[ede]

good stuff kyle. if anyone doesn't know Glock has opened up the standard armors course to anyone, as long as they're a GSSF member

[XRe]

That last point is pretty gnarly, isn't it? Dry firing a Glock w/ snap caps has got to be relatively hellish.... (relative to doing so w/ a 1911, or some other gun where you can re-cock the gun w/o cycling the slide)

Of course, has anyone here ever cracked a Glock breechface at all? I gotta suspect some of you guys are putting an awful high number of "dry snaps" on your guns...???

[shooter757]

I really appreciate that you took the time to post these notes. I took the basic armorer class earlier this year and I understand I have to wait three years until I can take the advanced course you just came out of. Sounds well worth it.

[BlackBuzzard]

In probably over 50,000 Glock rounds fired, I dont think I have EVER had a double feed.

Still its good to know how best to handle it, eh?

Now my AR15 is whole different story.

BB

[Micah]

Excellent info Flex, thanks!

Finally, on the subject of dry fire. Glock as admitted that the breech face wall is thin enough to be damaged with extremely high volumes of dry fire (e.g. hundreds of thousands of dry snaps per year.

Oh noes!!!!!!!!!!!!!

My cardboard-in-the-breech method has apparently saved the day

[NOMADSS]

Thanx that was great info!!

[Middle Man]

My friend FatDog had a great experience in Smyrna, ask him about the written test and essay questions some time...

[badchad]

Of course, has anyone here ever cracked a Glock breechface at all? I gotta suspect some of you guys are putting an awful high number of "dry snaps" on your guns...???

Not really a glock part but right before Area 2 I blew the breach face out of my Lone Wolf G35 slide. They say that's the first time it happened and they'll replace it free as soon as they get them back in stock. The guy I talked to over the phone thought it might have been from a high pressure round but it broke from inside out while I was dryfiring.

[Greg Bell]

Good stuff!

I learned the Glock double feed clearance from either Tom Givens or Jim Higginbotham several years ago.

[Flexmoney]

Dry firing a Glock w/ snap caps has got to be relatively hellish.... (relative to doing so w/ a 1911, or some other gun where you can re-cock the gun w/o cycling the slide)

No need to fully cycle the slide. The trigger will reset in less than a quarter inch of travel.

I have seldom reset the trigger in dryfire anyway...unless I am working on strictly trigger control.

[gotm4]

Great info Flex! I want to take the advanced class sometime. I just renewed my regular Glock cert. early this fall.

[hank2222]

so how about when the you are running custom cqb rail mounted weapon light and stike plate system with bult in red-dot scope mount system with

surefire m-300-weapon light and aimpoint m-2-red-dot scope mounted to the pistol on a custom stike -plate set up..

i have a custom design and made cqb stand off stike plate system for duty g-17-pistol ..

i have been useing heavy magazine springs in the mags ..but yet to have a failure to feed yet with unit attched to the frame and trigger guard unit

so i have been luckly so far..i have run about 2500.rds though the pistol, with this set up..

[RePete]

Good writeup Flex.

I was able to take the Armourers course in November, in Smyrna, due to the nature of my business.

A number of things that you said were given to us too, but I think the 1 item that was the best, is the ablitity to fire the gun with a broken trigger spring.

I can't take the Advance for 2 years.

[spook]

6. Scheduled replacement of parts. [...]

Recoil spring is the one that goes fastest, recommend replacement of the recoil spring assembly every 3-5K rounds for 9mm and every 2-3K rounds for other calibers. Officially you are o.k. if it passes the armorer recoil spring test, with an empty gun, cycle the slide, in a vertical position cycle the trigger and hold it to the rear, now pull back the slide and easy it forward VERY gently until it stops. Repeat several times. If yours stopped ever so slightly out of battery you need a new recoil spring.

Kyle, first of all, thanks for the great post. It's in my favorites

I have a question and I hope you can provide me with an answer.

This recoil spring test made me wonder. Will guns with lighter aftermarket setups (say a 13lbs. spring) fail this test?

Is there a difference between a "worn" factory recoil spring and a lighter aftermarket spring?

Did Glock give any potential scenarios of what will happen if you shoot the gun with a worn out factory spring? I can imagine the gun unlocking too quickly, thereby reducing accuracy (because the position of the barrel will vary between shots). But then again, won't this also happen with a 13lbs. aftermarket spring?

I have no other springs than the factory 17lbs. (although the one in the gun, which has been there for about 6k shots failed the test), so I cannot test this myself.

[Nik Habicht]

This recoil spring test made me wonder. Will guns with lighter aftermarket setups (say a 13lbs. spring) fail this test?

Is there a difference between a "worn" factory recoil spring and a lighter aftermarket spring?

I'm not Kyle --- but I've played with Glocks for a while now:

Guns with lower weight recoil springs won't necessarily pass or fail the recoil spring test --- it really depends on the gun and the spring. I've owned a G34 that would pass and reliably run with Wolff 12 lb. springs, a different 34 that would only pass and run with ISMI 13 lb. springs, and yet another that passes with ISMI's 13 lb. spring but runs more consistently with a 14 lb. or heavier spring.....

After running light springs for years, I'm back to running stock recoil springs in most of my blasters. If I shot more steel matches --- with 125s instead of 147s --- I might drop the weight again....

I've never found a stock recoil spring that failed the test; I have worn out Wolff 12s and ISMI 13s after 5-6,000 rounds.....

[spook]

Nik, thanks for the reply.

Since you mention only the test and reliability, I take it that a worn out spring will not affect accuracy, but only reliability?

[Flexmoney]

Just a point of order... That is not my write up. I copied and pasted it (with the author's permission) from another forum.

[Nik Habicht]

Nik, thanks for the reply.

Since you mention only the test and reliability, I take it that a worn out spring will not affect accuracy, but only reliability?

I've only noticed a cracked slide having an effect on accuracy --- even when I cracked a locking block in the 36, the gun kept humming like a Swiss watch and remained accurate.....

Worn springs don't seem to contribute to accuracy. I worry more about an out of battery detonation with worn springs than anything else....

[Miranda]

I ask here because this is where I read it.

In the copy. This line;

"That is of course an ammo problem, caused by setback, overcharge, powder contamination, etc."

What can contaminate powder and make a bigger boom?

I can imagine mixing powders might, is that the comtamination they mean?

miranda

[Tom in Ohio]

I don't believe that a too-light recoil spring will cause the slide to unlock while chamber pressures are too high. I believe the event is just too fast and it is the mass of the slide and barrel and the locking effect of the pressure on the breech face that keeps everything locked up until pressure drops after the bullet has left the barrel. I know that people have demonstrated this by firing 1911's with no recoil spring at all.

The problem in a Glock, though, is that the firing pin spring is pulling against the recoil spring. If the recoil spring is too light, you can actually pull the pistol out of battery while pulling the trigger. This is an important test if you have installed a light recoil spring.

One of the genius things in the Glock design is that as the springs wear out, they still stay in balance with each other as they act against each other.

[Brian Dean]

good stuff kyle. if anyone doesn't know Glock has opened up the standard armors course to anyone, as long as they're a GSSF member

I went to their website, and plan on joining. And although the dates and locations for the GAC are shown, there aren't any forms or links for applications

How did you go about your course? Should I contact GSSF? or am I missing something? Note also that the courses are being held at Police Departments. Is this a problem?

Thanks,

Brian

Edited January 19, 2009 by Brian Dean

[01G8R]

I just took the standard Armorers Course at the SHOT Show. I joined GSSF by faxing in an application and then I faxed the application in for the Armorers Course. Just list you are a GSSF member on the Armorers application and you shouldn't have any problem. One of the people from Glock Training called me to find out my GSSF number because it wasn't on my Armorer application. I explained that I joined GSSF at the same time I sent in the Armorers application. She said no problem and she would call over to GSSF to get my number.

I think the class is well worth the money and time. If you already know how to disassemble the Glock you are halfway there, but you will pick up some tricks and information about the company history. I would recommend it to anyone that uses a Glock on a regular basis.

[Suburban Commando]

I've heard about these 11 coil magazine springs a few times, but I've never seen one for sale. Do you have to order them directly from Glock?

[jobob]

Flex, thanks for the write up, even if you just cut and pasted it! Great c & p job, btw! I've taken the regular armorers course twice, and there is always something new I learn, no matter how much I think I know about Glocks.