Just Say NO

[eric nielsen]

Even with all the thousands of Glock posts, I think it's worth a new topic [rant] to cover this clearly: If you have a Glock that's built for Major ammo, shoot Major ammo through it.

I've sold 2 custom Glocks to 2 forum members, one Open, one Limited, both set up for 170+ power factor. Both new owners shot minor-PF ammo thru the guns and quickly developed large problems. I admit in the early 90's I did something similar which is shoot my Major powder charge behind a lighter bullet for each month's Steel match, and now it seems I'm lucky that gun (a G20) did not self-destruct as well. Maybe because those loads - for a 140-grain plated bullet - made about 145 factor.

Why it's important: The Glock system does not have the leverage of a hammer/mainspring combination to hold the gun shut at the moment of ignition. ALL it has to hold the gun closed until the bullet leaves and the chamber pressure drops to some reasonable level, is the force of the recoil spring at minimum compression. It's not zero compression but it's the longest length (captured) these springs ever see.

Some people like to tinker with light Glock recoil springs (<15 lb); the reasons mostly all have to do with the gun's behavior at maximum compression, slide to the rear. Their sub-minor WWB cases aren't kicking out of the their G35 with 9mm conversion barrel. Or they are looking for less (zero) muzzle rise. Whatever. So they go lighter and lighter with no end in sight. This is not a valid choice with a striker-fired gun and especially the Glock pattern which includes a trigger-press/striker-spring-compression that works in complete opposition to the recoil spring holding the gun closed. It's a bad enough idea in an M&P, if you haven't seen it search their forum for "FTE" or "failure to extract". It's a worse idea on a Glock.

The first and most important thing your Glock slide spring has to do is hold the slide closed while powder is exploding within the barrel. If your ammo can't overcome that minimum amount of force, use stronger ammo. Or sell the gun to someone who will.

[daves_not_here]

+1!!!!

This is a safety issue. It's always good to hear a new angle on safety that attempts to inform more people. Gun sales are at record highs and new gun owners will experiment.

The mainspring also has the striker spring working against it.

I've heard stories of people clipping springs and wondering why their gun won't go back in battery. It's got to push against the striker spring. On top of this, when the trigger is pulled there's even more opening force...just before ignition...

Makes me wonder if some of the KaBooms are because of this.

DNH

[eric nielsen]

From 2005:

The Vertical Test for Glock springs is something you should do frequently:

1. Unload the gun

2. Check AGAIN that the gun is unloaded

3. Point it straight up vertical and rack slide back

4. Release slide slowly - it should close by itself

5. Pull trigger slowly - the slide should not back up AT ALL.

If it fails this test, your Glock has too much striker spring fighting against too little recoil spring. Up the recoil spring weight or drop the striker spring weight or both. [Don't do this at a match, they frown on dry-firing at anything but a backstop]

A lot of internet chatter repeats step 1-4 above and never tests the trigger press. The person who showed me #5 (almost 20 years ago) was Todd Jarrett, who just wanted to see my sight picture but also tried my G20's trigger. At the time almost no spare parts were available for Glocks - you hacked up what you had in the gun and if you went to far, you put the gun in its box, sent it to Glock, and it came back with new parts and the trademark 6-lb trigger break. That's how I got a new recoil-spring assembly to replace the one where too much O.D. was taken off of the spring coils. Wild guess that was a 14-lb spring that ran minor steel loads and failed the Vertical test.

There's a lot of slide-to-frame slop in most Glocks, so a slide that hunches down toward the bottom of the magazine is normal. What's not normal is a slide that goes back in the direction of racking the slide. It can't be proved but i'm guessing that a lot of KBs were caused by slide back-out. The Glock was designed to have a small number of parts; some of the parts do 2 or 3 jobs and compared to other guns it operates in a narrow envelope of safe/reliable function.

[waktasz]

I shoot a 13 pound spring minus 2 coils with major ammo. Is my arm going to get blown off?

Stupid thread.

[daves_not_here]

waktasz,

Stupid thread? I don't understand, please elaborate.

I am relating the spring issues that a RO has seen at the gun range he works.

Modifying guns can have undesirable results so I think it should be done carefully and with in-person guidance.

DNH

Edited January 10, 2013 by daves_not_here

[redmanfixit]

I find that mostly these days people have no practical understanding of how things work. No understanding of how things are made. (we make nothing ordinary here now only expensive military doo-dads) There has been a steady decline in the intuitive awareness that comes from having the skill set in the general population that comes from actually knowing how to harden a spring or broach a barrel. These things are 2 tiny examples of the loss of knowledge.To actually be able to make something. Most people only know how to go buy a new one. Some of the responses here are the sort you get from a kid that's packed his cheap airsoft spring gun with sand and is mad because it stopped working. Wants what they wants.

[daves_not_here]

redmanfixit,

I'm tapping out of this thread. You hit on some major rant subjects...and...I...must...maintain...control.

Maybe we can migrate this thread on glocktalk? The full-contact cage-fight forum!

Be safe,

DNH

[waktasz]

waktasz,

Stupid thread? I don't understand, please elaborate.

I am relating the spring issues that a RO has seen at the gun range he works.

Modifying guns can have undesirable results so I think it should be done carefully and with in-person guidance.

DNH

I bet the majority of us that shoot Glocks in competition are running sub 15 pound springs. Making bold blanket statements with underlines under them when clearly people have been doing this for years is a little silly.

Yes if you are running a stock striker spring and an 11 pound recoil spring you will likely have problems, but that doesn't mean you can't experiment with non-stock setups.

[Flexmoney]

I shoot a 13 pound spring minus 2 coils with major ammo. Is my arm going to get blown off?

Stupid thread.

We discuss things in a respectful manner here. We SHARE ideas here. You don't have to agree with them, but you do have to post respectfully. If you aren't into that, you can choose not to post. - Admin.

[Mark R]

I have an aftermarket (non-captive) guide rod, 12 pound recoil spring, and a lightened striker spring I've used since my first Glock (G22), now on my second (G35), both 40 cal...and I shoot minor and major loads with no issues. Not to say I won't, but haven't yet.

edited to add: non-captive guide rod/spring.

Edited January 10, 2013 by Mark R

[eric nielsen]

I wrote down a rant. I figure quite a few people will choose to disagree. Worst thing that can happen is maybe a few people who now know better go and ruin a few hundred bucks in shooting gear and possibly get a few stitches in their hands. Small potatoes compared to when I can convince one person to stop smoking cigarettes. Been called a lot of things; stupid is one of the lesser-used descriptions. But hey sometimes that one is accurate too.

[Joe4d]

Seems like the OP doenst quite understand the concept of lockup. Glocks arnt blowback.

[motosapiens]

So is this thread saying that glocks aren't safe, and shooting lower-power ammo will cause them to blow up?

Glad I shoot a proper metal gun that can handle a wide variety of loads.

[Flexmoney]

Seems like the OP doenst quite understand the concept of lockup. Glocks arnt blowback.

He understands it, as applied to a Glock.

So is this thread saying that glocks aren't safe, and shooting lower-power ammo will cause them to blow up?

Not sure about the mention of the low powered ammo. I am assuming he meant that as being a reason for putting a lighter recoil spring in the gun.

Regardless, it is a scientific fact that pulling the trigger puts rearward pressure on the Glock slide. There is a simple test (listed above) that allows any lay-person to test if their setup goes beyond the threshold of safety...which is the gun unlocking.

[motosapiens]

So is this thread saying that glocks aren't safe, and shooting lower-power ammo will cause them to blow up?

Not sure about the mention of the low powered ammo. I am assuming he meant that as being a reason for putting a lighter recoil spring in the gun.

Regardless, it is a scientific fact that pulling the trigger puts rearward pressure on the Glock slide. There is a simple test (listed above) that allows any lay-person to test if their setup goes beyond the threshold of safety...which is the gun unlocking.

It was the mention of 'if you have a glock built for major ammo, shoot major ammo through it.

the trigger putting rearward pressure on the slide is an interesting and useful piece of information however. Easy for that to get lost in the somewhat alarmist tone of the original post.

[MarkCO]

Powder does not "explode" and the general tone of the OP is alarmist. It could have (should have) been written better as the OP is tying together issues that are not necesarily connected. When you want to toss a hand grenade, make absolutely sure you are tossing it in the right direction!