Glock Armorer Research

This is an article I put together a while ago, a long while ago while trying to learn about building glocks and aftermarket parts. Finally have all the components and built one gun based on a G22 40cal and then sold it haf way through . It worked out cheaper to purchase a Zev. Everything done out of the factory. I had started to get back into pistol shooting while still on oxygen and gave this to one of the instructors whom was an ex federal police instructor. He had never seen anything like it and I was told that it had more information than in the glock Armourers course.. i no longer shoot. Due to state laws I travel around too much to keep up with storage regulations. I havent checked links but have left them there for quoting sources of information.

Building a Glock Research

I was undecided on whether to start and do a build on a custom STI tactical 4.15 with an extended 5 inch barrel to be of legal length in oz or buy a Glock and came across the following picture on the m4carbine forum, which sort of settled the choice for me. That and finding several Australian importers of glock parts, that hadn’t been available to me in the past making buying the accessories and parts much easier than importing from overseas due to current import restrictions. It also allowed me to do most of the work myself, unlike working on a STI 2011. http://www.m4carbine.net/showthread.php?t=95628

The following link describes how to break the trigger down into its separate components, in order to understand how modifying each one can change the characteristics of the trigger and gun as a whole. http://militarytimes.com/blogs/gearscout/2012/01/01/glock-setup-tips/

There are three main components to the Glock trigger action that determine pull weight: the connector, firing pin spring, and trigger spring. I will be discussing these along with barrel choices, guide rod recoil springs, guide rod weight and combinations of these. The following information is all I could find to learn about building a Glock, since I had never owned one before.

Firstly Guide Rods;

To start with in Glocks guide rods have absolutely no effect on the accuracy of your pistol. In a standard 1911 the guide rod, being so short, only guides the spring at the end of the rearward action. This allows the spring to move from side to side in the frame channel and could allow interference. The full length guide rod forces the spring to stay centered and slide along the guide rod reducing the interference. Ti is worthless for guide rods, you want heavier not lighter. Steel is only slightly heavier but if you are really in tune with your gun you can feel a subtle difference in the handling. Tungsten is much heavier than steel and makes a significant difference.

Below are some guiderod weights. Aftermarket rods are all same brand. Weights do not include the recoil spring.

Stock 17 2.04 grams = 0.071 ounce

Captured Stainless 17 18.3 gr = 0.645 oz

Cap Tungsten 17 34.18 gr = 1.206 oz

Non-cap Tungsten 34 44.56 gr = 1.572 oz

When compared to stock the tungsten is significantly heavier. When compared to stainless the tungsten is almost double the weight. Here is where it gets real interesting. An empty G17 weighs 625 grams. Adding a captured tungsten rod increases the total weight of the gun by more than 5% and in a key location. An empty g34 weighs in at 650 grams. With an extended tungsten rod you are increasing the total weight by almost 7%.

Something that weighs less than 2 ounces may not seems like much but it does make a significant difference in recovery from recoil.

My personal view

I’m using a model 22 in 40cal and converting it to a 9mm. This will bring up the barrel wall thickness and also the front weight of the firearm. I am therefore sticking to a steel guide rod. If I were using a stock thickness competition barrel I would then use a Tungsten rod.

Captured Vs. Non-Captured;

I personally use non captured rods. It is easier to swap out springs and with a little practice it is not any harder to assemble your pistol. There is no mechanical advantage or disadvantage to either, it’s just personal preference. If using a single load, such as when reloading a captured system is easier to install when cleaning. It’s similar to a bolt with a nut on the end that keeps the spring under tension. The advantage of non-captured is when working up loads or using more than one type of factory load and wanting to tune the firearm to the load being used. I generally use three different loads. A 147 grain subsonic at 980fps, my usual load is a Hornady steel match 125 grain running at 1100fps that cost $280 per 500 and ex-military FMJ plus P loads which cost $350 per 1000 rounds. An uncaptured spring set up allows me to change them out using a $12 spring, whereas with a captured system you have to replace the entire guide rod and spring.

Barrels;

KKM vs. Stormlake vs. Lonewolf. There are three links below comparing the three brands. From what I can tell there isn’t that much difference. If I were to choose a standard wall thickness match grade barrel, to fit in a standard slide assembly 9mm to 9mm, without opting to use a conversion/bull barrel 40smith to 9mm luger. I would probably choose a KKM due to the type manufacture, using button rifling.

Button rifling is a process, in which a Titanium Nitride coated Carbide button is pulled under pressure to displace metal to produce a rifled barrel. This process is very expensive but produces a better finished size, surface finish, and surface hardness as well as maintains a more uniform rate of twist than any other rifling process. Each button can be used to produce thousands a barrels before wearing undersized. This allows us to maintain the highest level of quality control.

That’s if I wanted to wait 6 months for the import process to occur in this country and could be bothered filling out B709 forms. If choosing a bull barrel style conversion it would be between a Stormlake and a Lonewolf as KKM don’t make a conversion barrel. The same import process would be required for the Stormlake. Lonewolf have an importer listed below. Hence the lonewolf is my choice.

Note: I have been told that KKM barrels are very tight and some require minor fitting.

Trigger Springs;

The NY trigger are a coil spring within a frame as opposed to factory coil spring, the modules alter the internal geometry and relationship of the trigger linkage. You now have a spring pushing straight up on the back of the cruciform, instead of applying pressure at an angle. The result is a smooth trigger pull and a clean break, with a lightning-fast reset.

http://www.glockmeister.com/TriggerSpringInstallation.asp

Dawson are just reselling the Glock Triggers kit. It removes pre-travel and gives a nice trigger: reduced travel and light pull, not for use on anything but a competition gun. I would offer one word of caution: you need to be very careful about setting the over travel stop and make sure that it does not creep out of adjustment, by using a little blue Loctite.

The Ghost Rocket is not a trigger kit, it is just a connector with a fixed over travel stop that needs to be fitted to an individual gun by filing. It works well, but it is not a complete trigger kit.

NOTE; If you have a Glock that has a couple thousand rounds through it your trigger is already lapped in. If you replace the trigger bar or connector in this gun, it will feel terrible. Any part that is replaced into a lapped system needs to be lapped in itself before a reliable evaluation can be made.

Guide Rod/Recoil Springs;

Effects of a lighter spring: Recoil is transferred to the shooter in a shorter duration of time because the slide is moving at a higher velocity. This is often perceived as less recoil and reduced muzzle flip. With a lighter spring the shooter also has less force to counteract, or you don’t have to work as hard. This usually reduces muzzle flip. Less force to counteract reduces the odds of producing a limp wrist style jam. A lighter spring will result is reduced muzzle dip when the slide closes keeping sights steadier and on target for a faster follow-up shot. Light springs are particularly helpful to smaller shooters like children, women or anyone else having trouble keeping their wrists locked.

Effects of a Heavier spring: Recoil is transferred to the shooter over a longer duration of time due to lower slide velocities. Slower slides equal a longer recovery time for the shooter. The shooter does more work, as there is more force to counteract. This often causes and increase in muzzle flip. The chances of a limp wrist style jam are increased, as there is more force working to unlock your wrists. The chance of the slide short stroking and causing a feed jam is increased. Increased muzzle dip when the slide closes for a slower follow-up shot.

Brass Ejection: It does not matter how far away it lands or if it is in a neat pile. You are there to shoot not to pick up brass.

Frame Battering: A non-issue for Glock pistols. It falls under the category of Internet Nonsense along with the idea that light springs cause kabooms and broken parts.

Spring Selection and Testing: There is no magic weight that is perfect for all shooters, loads and guns. Each shooter must evaluate and test various weights to determine what is best for their application. For rough tuning try different standard weights. For fine-tuning, take a spring slightly heavier than you prefer and trim it until it is just right, this is a trial and error process.

NOTE; MATCH THE SPRING TO THE LOAD.

If trimming springs. Start by removing 1 coil at a time and then check for full travel. Trim until the slide has full travel then check for proper lockup. You can go too light: The firing pin spring can overpower an old or too light recoil spring causing the slide to pull slightly out of battery as you pull the trigger resulting in a light primer strike. If you have off center light primer strike this is probably the cause. Feeding jams; The slide can be so fast that the mag spring cannot keep up.

By using 11 pound recoil springs should greatly reduce or eliminate the need for cutting 13s and should work great in the 9mm guns and the compacts.

IMPORTANT NOTE:

Factory recoil spring ratings above are for current production models with captive factory recoil spring systems which are silver/gray in color. Previous captive factory recoil assemblies for the 17, 17L, 20, 21 & 22 had recoil springs rated at 16 pounds. Earlier non-captive models of the 17, 17L and 19 had factory recoil springs rated at 19 pounds. Not for use in Generation 4 pistols.

•Reduced Power…: 10, 11, 12, 14, 15 & 16 Lb.

•Factory Standard.: 17 Lb.

•Extra Power………: 19, 20, 22 & 24 Lb.

Recommend starting springs weights:

G17 13lb

G19 13lb

G20 15lb

G21 13lb

G22 15lb

G23 13-15lb

G24 13lb

G31 15lb

G32 13-15lb

G34 13lb

G35 15lb

Spring setups:

G34 Production 13lb minus 4 coils

G35 Limited 15lb minus 3 coils

G17 Open 13lb minus 5 coils

G19C Carry 13lb minus 6 coils

Choosing Spring Weight. This part is not as simple. Selecting the proper weight spring is part of the weapon tuning and will depend on what your end goal is to be. The standard weight spring, in the case of Glock 34, of 17 pounds is used to match the average slide performance with industry standard loaded ammunition. This is to ensure maximum reliability for a weapon right out of the box. In your tuning, if you prefer a snappy slide that opens and closes more quickly, you would want to go with a heavier spring and ammunition that has a lighter weight bullet, such as 115gr. You want to make sure you don’t go too heavy on the spring or it could prevent the slide from going all the way to the rear. This would not allow for proper empty case ejection or failing to strip the next round from the magazine. If you would like a slide that is a bit slower and has more of a push feel then a snap, you would go with a lighter weight spring and a heavier bullet, such as the 147gr. Because of the added weight, the round is a little slowing in getting moving and this produces the push feel. Again, don’t go too light on the spring as this will allow the slide to hit the slide stop too hard and cause damage. For a Glock, a good test is to make sure the weapon is not loaded, pull the trigger and hold it. Point the barrel straight up and pull the slide all the way to the rear. Do not release the slide but slowly ease it up until it stops on its own. If it fails to go into battery, on its own, the spring is too light and may fail to chamber a round and go fully into battery.

One thing to remember once you do this, if you tune your weapon for the light bullet/heavy spring, firing rounds with a heavy bullet will not function the same. But, the other way around, firing a light bullet in a weapon tuned for the heavy bullet/light spring, could damage the weapon.

If you have a heavy spring most of that energy is displaced in the spring, resulting in a softer push feeling. If you have a weak spring only a small amount of the energy is displaced in the spring and the rest is displaced when the slide slam’s in to the frame.

If an egg is thrown at you can catch it one of 2 ways. You can just stick your hand out and let it smash in to your hand (weak spring). Or, you can draw your hands back with the egg and absorb the eggs energy without breaking it. This creates a more even disbursement of the energy (heavier spring).

Either way your hands absorbed the eggs energy. Catching it differently didn’t change it’s energy. It only changed how the energy displacement was felt by both you and the egg.

Changing spring weight doesn’t change the energy going in to your hands, Just how it’s felt or perceived. A light spring may feel snappier than heavy but there is less muzzle flip for a shorter duration. It also produces less push than a heavy spring; it is a short tap instead of a long push.

1. Try a little experimentation for yourself if you have not already. A few rounds with a 15# spring, a 17# spring and a 20# spring won’t hurt anything.

2. 1911s are NOT Glocks. They have different kinematics and differences in the way the forces are transfered through the frame, due to geometry and material properties. Even the mathematical models show this pretty convincingly. The friction on Glock pistols between the frame and slide is less than in a 1911, the bore is lower and the frame flexes more.

3. For 4 shooters, in a Glock 22, target acquisition, split times, perceived recoil, timing drills were always at least the same, usually better when the spring weights were increased. We went from 15# to 17# to 20#, 150 rounds each. Every shooter prefered the 20# spring. The round we used was Pro-Load 165 grain Tactical Grade (1100 fps chronographed) and a reload that duplicates it (165 Berry’s at 1100 fps). The spring weights were measured and we had to switch 1 of them to make sure the actual weights remained constant.

4. Frame battering, in major caliber Glocks, if you want your pistol to last past 50K rounds or so and REGULARLY use hot or Plus P ammo, then a bump in recoil spring weight will help the gun last longer and allow more reloads on the brass.

5. For the average shooter, I doubt most will ever shoot past 50K rounds on a gun, and the vast majority will be plinking rounds if they do.

6. A factory Glocks trigger (5.5 pounds) precludes any slight advantage that softer springs may have in medium power loads as far as timing and increased performance is concerned.

7. Buy a case of ammo or load 1000 rounds up and get yourself 3 spring weights and match your pistol and load to your shooting.

Connectors;

Everybody seems to want a 3.5lb connector because it is “THE BEST”. The truth of the matter is a 3.5lb connector delivers the lightest trigger pull BUT it also delivers the longest pull available. A lot of shooters confuse the 3.5 connector as a mushy system because it has so far to travel. It is hard for some shooters to grasp this theory because they are thinking less (3.5lb) is best? Try to think of it this way: You want to load a 55 gal drum into the bed of your truck.

1 You get a 30 foot plank and roll the barrel along effortlessly but it takes a long time to get the barrel in the truck. (3.5lb connector)

2 You get a 15 foot plank and roll the barrel along. This requires more effort but it doesn’t take much time to get there. (5lb connector)

3 You get a 5 foot plank and roll the barrel along. Man I noticed the effort here but the barrel was instantly in the truck! (8lb connector)

Factory connectors have less of an angle at the contact point with the trigger bar, less that stock = less resistance. The “+” connector has a greater angle, greater = more resistance. Difference either way is about 15 degrees.

Using a 3.5 lb. Trigger Connector: The factory trigger pull on a Glock is similar to shooting a staple gun. It has a long pull and a slight snap to it as the striker releases. The 3.5 lb. drop-in replacement connector gives an immediate improvement in trigger performance on the Glock pistol. The lighter trigger pull weight and the highly polished, nickel-plated surface make the pull smoother and more consistent. It helps the trigger reset more quickly for faster follow up shots and less temptation to jerk the trigger and compromise accuracy. The imported Glocks to Australia use an 8lbs trigger pull.

Combinations;

While doing my research, I came across this useful guide on trigger spring / connector combos. It was originally on this web site http://gunlovers.19.forumer.com/viewtopic.php?t=441

Actually, that link was quoting another article by T.R. Graham. Just want to be sure to acknowledge the original author.) I thought this might be useful for others:

5.5 lb coil trigger spring + 3.5 lb connector

This trigger setup generally gives a nominal pull weight of between 3.5 to almost 6 pounds, and has a somewhat long and “spongy” trigger feel in most guns. An excellent trigger combo for target use, but because of liability concerns it is not normally recommended for defensive applications.

5.5 lb coil trigger spring + 5.5 lb connector

Nominally breaking at 5.5 lbs, and by far the most commonly encountered of all the GLOCK triggers, this factory standard combination is the one that will have the most variation in overall pull weights between guns. Due to various lockwork tolerances a typical stock GLOCK “5.5 pound trigger” can and will break anywhere from 5.5 pounds to almost 8 pounds in a new and tight pistol.*

5.5 lb coil trigger spring + 8 lb connector

One of the least encountered of all the heavier GLOCK factory triggers, this trigger setup is also one of the least desirable, combining and magnifying the vague “spongy” feel of a stock 5.5 coil trigger spring with a stiff 8 pound “+” connector. Although mainly found on police issue GLOCKs, it is a poor choice for defense use, and this trigger setup is emphatically NOT recommended for competition use.*

8 lb NY1 (green) trigger spring + 3.5 lb connector

This almost bulletproof combination will generally give a nominal pull weight of between 4 to 6.5 pounds in most guns, providing a trigger with a much more defined takeup and a much crisper release point. Because the NY trigger spring is virtually unbreakable, this is an especially useful trigger setup for guns used for both competition and defense applications.*

8 lb NY1 (green) trigger spring + 5.5 lb connector

The most widely encountered of all the “heavy weight” GLOCK triggers, this combination gives a nominal pull weight of between 8 to 12 pounds, depending on the gun. Like with the 8 lb “NY” # 1 trigger spring with a 3.5 lb connector, the trigger takeup is firmer and more defined, and letoff and trigger reset is much crisper than the stock 5.5 lb trigger. Also, unlike the stock coil trigger springs, the “NY” trigger springs are virtually unbreakable in normal use, making this an excellent setup for hard duty or rough condition use.*

11 lb NY2 (orange) trigger spring + 3.5 lb connector

This combination feels much like a 8 lb “NY” # 1 trigger spring with a 5.5 lb connector, breaking at or about 9 to 15 pounds. Applications include rough duty or home defense use. Recommended only as a substitute when a standard “NY” # 1 spring cannot be installed.*

11 lb NY2 (orange) trigger spring + 5.5 lb connector

The super-heavy weight of GLOCK triggers, this combination averages from 11 to almost 20 pounds trigger pull. Of limited use, applications include home defense for people with young children, or with persons having especially large and strong hands.*

EITHER of the NY trigger springs + 8 lb connector

NOT approved by the factory. As well as giving a incredibly heavy trigger pull, installing these two components together can cause failure of the sear kickup on the trigger drawbar to drop down far enough to clear the firing pin lug with some guns. In effect, although the trigger will move back and forth, the pistol will not fire. Furthermore, if this happens the pistol cannot be field stripped to remove these components without first removing the firing pin mechanism from the slide.

Trigger Recipes

1) 8 lb NY1 (green) trigger spring + 3.5 lb connector. This almost bulletproof combination will generally give a nominal pull weight of between 4 to 6.5 pounds in most guns, providing a trigger with a much more defined takeup and a much crisper release point. Because the NY trigger spring is virtually unbreakable, this is an especially useful trigger setup for guns used for both competition and defense applications.

2) For a 5-6 lbs trigger it would be very easy. For a true 6 lbs spring use the factory springs and connector. For a 4-5 lbs spring either use our connector or trigger spring with the factory firing pin spring. It is not an exact science but going heavier is always easier than going lighter.

3) Here’s a suggestion that may prove somewhat controversial: Use a 4 lb connector (Glock works has them) and get yourself a NY #1 trigger module.

4) Lone Wolf 3.5 connector

Lone Wolf Ultimate Trigger Stop

Lone Wolf 4 lb striker spring

Lone Wolf 6 lb trigger spring

Polish the trigger bar “birds head” flat and edge where it contacts the connector also the raised angled edge where it contacts the firing pin safety and the “kick up” edge where it engages the striker leg. Polish the leading edge of the firing pin safety and the face. Polish the face of the striker leg.

Squirt a little “Flitz” between all bearing surfaces of the trigger system. (everything you polished) Keep it there for a few hundred rounds then clean all the parts and check the bearing surfaces. They should be lapped in completely. If so, replace the Flitz with a small amount of quality grease or oil. If not, add a little more Flits and check it again in a couple hundred rounds.

Special note: You can use this recipe with any connector, 3.5/5/8. Try them all and pick the one best suited to your style shooting

For rough tuning try different standard weights. For fine-tuning, take a spring slightly heavier than you prefer and trim it until it is just right, this is a trial and error process.

5) The fulcrum trigger will indeed lower the trigger pull though. Installing a 3.5 connector w/ ny trigger spring will make reset better and polishing the firing pin and replacing the firing pin spring will shorten reset.

6) The heavier trigger spring will lighten the trigger a good bit, particularly during takeup. The lighter connector doesn’t change takeup at all but will make the break lighter. It will also tend to make the break “mushier”. Some folks don’t really notice the “mushy” or don’t have a problem with it.

Things to look out for;

If you reduce the poundage you will increase wear on other components such as the lower barrel lugs where they make contact with the vertical impact surface. The process of extraction and ejection are altered in fact that is how one might tell they need to replace their springs when you see the casing being thrown into another time zone.

The relationship with magazine springs and followers can affect how well the pistol feeds and is often referred to as the primary cause of malfunctions. On the flip side, running your gun in a dirty environment, or wanting to insure your gun cycles reliably, some folks recommend raising the poundage to 17-18 lbs. Duty guns.

Competitors tune their recoil springs as mentioned for soft ammo using the idea of managing the recoil so they get back on the target faster. At this point they add a little weight so they might reduce muzzle flip.

You can play with these ideas along with downloading your ammo but the standard weight of 16 lbs for recoil springs and practicing will likely be better for you than tinkering and losing confidence in your pistol.

Peening happens because the frame flexes under recoil allowing the locking block to move upwards and hit the slide.

The most common approach to dropping trigger pulls is to replace the factory firing pin spring with a lighter unit. Unfortunately this makes the gun sensitive to primer hardness. Run hard primers with a light firing pin spring, you will get misfires. If you can always control what ammunition goes into your gun by choosing only ammunition that uses federal soft primers.

Explaining Pre-travel, Reset and Over-travel

1.Pre-travel. Pre-travel is the amount of ‘slack’ that must be taken up before the full weight of the trigger begins. Some pre-travel may give the user the ability to feel the trigger prior to discharge, it also increases the length of pull, which may add some safety margin.

2.Overtravel. Overtravel is the amount that the trigger is free to move after the point at which it activates. In most applications, minimal overtravel is consdiered advantageous as it prevents any jarring caused by the trigger hitting a sudden stop after release. With self-loading firearms, overtravel considered detrimental because it increases the reset distance.

3.Reset. Reset is the distance the trigger must travel forward (as pressure is released) before the trigger is ready to be fired again. Reset is not a concern in single-shot firearms, but in self-loaders where a fast follow-up shot may be desirable, a short reset is preferred.

In conclusion;

As with any modifications or gunsmithing tips, take them with a grain of salt and do your own research.

What I would like to achieve is a 5 pound trigger pull to bring it down from the 8 pound factory weight. Essentially a tactical trigger system, not as light as a competition trigger but not as heavy as a duty trigger where you end up missing the target. Have a medium trigger pull and a short reset using a Zev Industries model ZT-STD-D-9-TAC as a base to work from, being made from CNC billet aluminium. Then play around with a 14 pound recoil spring, Ghost 3.5 lbs tactical connector and Light New York trigger spring and see what happens.

Amendment’s;

Found out some more information since writing article. I will be using a full fulcrum kit. The trigger is billet aluminium and not polymer. It’s also three times wider, better for accuracy. Will also need a 9mm trigger kit to use in a converted 40cal as the ejector pin is slightly different in a 9mm compared to a 40.

Glockworx Triggers

http://www.glockworx.com/Products.aspx?CAT=3688

Ghost Connector Tactical 3.5 lbs

http://www.ghostinc.com/category/50_tactical/

NY trigger Spring

http://www.rockyourglock.com/custom/TriggerSprings/GLO-7405BK2.htm

Links

Anarchangel Blog – How to make a Glock not Suck

http://anarchangel.blogspot.com.au/2005/03/how-to-make-glock-not-suck.html

Modding the Glock – By Duane Thomas

https://www.usconcealedcarry.com/ccm-columns/features/modding-the-glock/

Glock Tech – Recoil Springs, guide rods, Connectors