How Do You Measure Glock Trigger Pull Weights?

[Flexmoney]

We got a lot of numbers posted on trigger pull weights. I can see quite a bit of variation depending on what method I use to test the pull weight.

I am wondering how others do it on the Glock?

[Clay1]

I use an RCBS scale. The trigger hook is thick enough that I can place the hook at the very end of the trigger by the trigger guard and do my check. It holds down the trigger safety and the scale hook rides next to the trigger guard. This gives me the best mechanical advantage to read the scale as well as producing a repeatable reading. My Ralph S. trigger is breaking about 2.25 pounds these days in my G34. I need to clean and lube and it should get back to about 2 pounds with this method.

Rick

[Flexmoney]

Thanks Rick. Are you able to pull straight to the rear, or do you have to pull at a bit of an (downward) angle ?

(Could anybody that could take pictures of their methods...and post them?

[Matt Cheely]

I try to get the scale as low as possible on the trigger, maybe 1/4" from the bottom. I have to start with a downward angle to start and as the trigger comes back, decrease the angle till it is parallel with the top of the slide when the trigger breaks.

[SRT Driver]

Flex,

I use NRA weights to get a rough estimate and also use an RCBS scale to get weights under 2 lb.

To use the RCBS scale:

Set the gun down on a table the front of the slide and the magwell touching the table. Like you were shooting slowfire bullseye. Hold it in your weak hand.

Put the trigger scale on the bottom of the trigger far enough to compress the trigger block safety with your strong hand. I made a shoe that is shaped like a Glock trigger with a hole in it for consistency sake.

Pull it to the rear.

This method seems to be very accurate. My reading matched Charlie's when he did the trigger in my G34.

[jspruance]

Flex,

I wrap some electrical tape around the safetyand the trigger. I build it up a little so that the shaft on the trigger scale has a constant location for repeat pulls. I try to pull about 1/4" from the bottom and straight back. Ralph trigger in my G34 pulls a constant 2 3/4 with my RCBS premium trigger pull scale.

[dajarrel]

complete and total thread drift mode on.....

Flex, Have you turned your avitar over or am I just dreaming. I could have sworn the target was once presented in the heads-up direction.

Sorry for the drift,

drift mode off/

dj

[cautery]

Well Flex, you've read my "Trigger Weight: Putting your trigger on a diet!" article right.

I just bought one of those fancy, schmancy digital trigger pull weight scales a few weeks ago. While I don't really doubt the accuracy of the scale itself, I DO doubt the accuracy of measurements with it (mostly repeatability/consistency) when used "hand held".

You already hinted at one of the major issues for our Glocks: the angle change during the pull through.

Here's a list of things off the top of my head that make hand holding the trigger scale less than desirable (on Glocks at least):

1) On a STOCK trigger system, the pull through angle changes radically from start to finish. As stated, you often have to pull "down" or at an angle to the plane parallel to the long axis of the slide.

2) Because of the long pre-travel, and the starting angle, it is hard to get the trigger scale rod to ride in the same place throughout the pull or from one pull to the next.

3) IF you pull from the tip, the scale usually rides on the tigger guard for part of the pull which adds artificial drag to the pull as long as the scale is in contact with the trigger guard. (Not to mention that the additional lever lenght artificially reduces the actual pull weight when there is no contact with the guard).

4) If the scale is pulling at ANY angle other than exactly parallel to the long axis of the slide, you are not getting a true reading, and thus the reading cannot be compared to any other reading.

5) Pulling through anywhere but the center of the trigger gives a less than accurate result... Your finger neither pulls through on the tip or up at the top of the trigger safety... If your finger WERE pulling at the tip, (or 3/4 down) it would be dragging on the trigger guard.... no one wants that becasue it's slow.

6) The trigger safety gets in the way of most conventional trigger scales...

7) Pulling through with the scale by hand is a woefully innacurate way to measure pull weight. No matter how good you are, you risk inconsistent pull angles and over/under readings due to the inconsistent nature of the human pulling mechanism... ie: hand.

... and a lot more that I can't come up with right now.

<begin anal retentive mode>

OK... Here's the way "I" think a trigger pull weight should be determined...

1) The pistol needs to be held static (like in a vice or jig) with the long axiz of the slide EXACTLY perpendicular to the ground.... Gravity acts in toward the center of the Earth... This gives you a consistent starting point for the measurement process.

2) IDEALLY, you would want to use dead weight to create the pull... e.g. like in my article using brass cases... about 74gr per piece. You figure out the dead weight, then measure it on a good balance beam or other lab quality scale... This gets you the best apples to apples comparison, as balance beam scales if zeroed are all pretty close to each other... especially O'Haus or better triple bemas. However, trigger scales are widely used, and can be used fairly accurately IF you make sure they are accurate within the range you are measuring.... the best way to do this is to suspend a known weight (standard) from the scale vertically to make sure it is accurate.

3) Now... to use a trigger scale, first you have to make sure it will ride in the center of the trigger during the whole test... You can tape (or otherwise fix/disable) the trigger safety down (better if it has been shaped to be flush with trigger when depressed).

4) Next, on trigger scales with those rollers on them... need to take it off. The rod is smaller in diameter and makes a better pivot point.

5) You need to find the center of the trigger and mark it for lining up the rod on the mark/center of the trigger.

6) Then you need to create stops fore and aft of the ma rk to keep the rod in place. Ideally, these need to be hard and have a high lubricity... like Delrin or Teflon. I used masking tape in my article. It'll work, but there is a minute amount of drag.

7) The deal with using the rod, is that you have to worry about keeping it exactly vertical (parallel) to the pistol... This is hard to do considering it was not designed to be balanced... A better way, it to make a cross rod (balance rod) with a harness below it to hang the scale (or weight package) on. If the rod is on your mark and exactly parallel to the ground, you know you are pulling straight through every time. (Note: I put a sight notch on mine, so I could measure total trigger pull length and graph pull points vs. weight applied... This allows you to find hitches in the pull and address them to get a smooth even pull).

8) Now... Using a scale this way, you can leave the roller on it, because it can be used to hand the scale on the rod harness...

9) You need to have a hook or some other mechanism onto which you can attach a weight package... You COULD just pull it with your hand, but as I said, this is inconsitent... a waste really.

10) To the hook on the bottom of the scale you attach your weight package... It will weigh something (make it light... like a ziplock baggy with a coat hanger top frame to hold it open.

11) Now using brass cases, or some thing else with a small weight per unit, add weight (measure pull distance and weight as you go if you like) until the trigger breaks... Whatever the weight reads on the scale is your pull weight... If you are careful toward the end, and don't drop weights into the package, you should get a very accurate and repeatable measurement...

</end anal retentive mode>

As I have pointed out before, I am convinced that many of the figures quoted from trigger scales tend to be innacurate, and possibly/probably understated... spring scales are notoriously inaccurate... load cell scales are much better... BUT, gravity does not lie... If you use dead weight, and then measure that weight with a good balance or balance beam scale, you get a much more reliable figure.

Edited November 4, 2005 by cautery

[Kevin Kline]

Ive had the same problem, getting the trigger pull gauge to stick on the trigger. Ill try the electrical tape and see if that helps. I always try it, but it slips off and is hard to place it on the same place of the trigger and make it stay there.

[cautery]

If you are going to use tape... Use something with an adhesive tack that works better with the polymer you are about to apply it to... MOST electrical tape doesn't like to stick to Glock polymer...

[Bill Nesbitt]

**merged threads**

With the possibility that we might be shooting a Production gun in an IPSC match, I decided to explore trigger pull weights. I went to the IPSC rule book and started weighing our Glocks.

I have always measured the pull weight on Glocks near the tip of the trigger because that is where my finger does most of the pull. Our Glock 17's all weigh 2 1/2# to 3# using this method.

Using the center of the trigger as described in the IPSC rule book I'm getting pulls of 4 to 4 1/2 pounds.

Which is correct?

How about other guns like CZ's with a curved trigger?

I'm using an RCBS Trigger Pull Scale.

[robertbank]

With the possibility that we might be shooting a Production gun in an IPSC match, I decided to explore trigger pull weights. I went to the IPSC rule book and started weighing our Glocks.

I have always measured the pull weight on Glocks near the tip of the trigger because that is where my finger does most of the pull. Our Glock 17's all weigh 2 1/2# to 3# using this method.

Using the center of the trigger as described in the IPSC rule book I'm getting pulls of 4 to 4 1/2 pounds.

Which is correct?

How about other guns like CZ's with a curved trigger?

I'm using an RCBS Trigger Pull Scale.

Not sure of the method BUT the trigger pull weight cannot be less than five lbs. for IPSC Production. The CZ's are measured from the center of the trigger where the curve is at it's maximum. That is how mine was checked at the last Qualifier I shot.

Take Care

Bob

[JWBooth]

Bill,

I have always been told (both for USPSA, and NRA bullseye, and the Army) that it was measured in the center of the trigger. Even if the trigger is cuved or staight. The method that I have seen most: with an empty gun, cock it, and hold the gun barrel pointing straight up. Put the gage, or weight hook on the ceter of the trigger, and apply weight or pressure until it snaps. Make sure all safeties are off, including grip safety if necessary. Some tests are with mag. in place, some are not. In some guns it will make a difference. -JWB

[Flexmoney]

Usually, in the garage.

[DVC247]

Don't confuse him or yourself by saying IPSC. In America (USPSA) there is no minimum trigger pull. Outside of the U.S. the pull weight is 5 lbs.

Flex, you are a bad man.

[Bill Nesbitt]

If I were lucky enough to shoot the IPSC US Nationals (not USPSA) my Glock would need a 5# plus trigger pull.

[Bill Nesbitt]

I'm bringing this back around because my question was only partly answered.

This is for Glock shooters. Where on the trigger do you measure the trigger pull if you have, say, a 2# pull? I get a 2# difference between measuring on the center of the trigger according to IPSC rules or measuring on the tip at the bottom of the trigger.

I bought a drop in trigger kit a while ago. It was advertised to give a 2 1/2# pull. I only got that weight if I measured at the tip of the trigger.

An update on the IPSC match. I shot revolver and Susan shot Standard so we didn't have to mess with her gun.

Bill

[Dan Sierpina]

Bill,

I've always measure the trigger at the curve, where the weights would naturally come to rest. Yes, weights, not a scale, gravity is constant.

[Bill Nesbitt]

Hmmmmm. Not many answers yet.

I'll ask again.

For you Glock shooters that have a sub 3 # trigger pull; where on the trigger do you make the measurement?

It seems to me that the middle of the trigger is around where the pivot pin for the trigger safety is.

[Bill Nesbitt]

Bill,

I've always measure the trigger at the curve, where the weights would naturally come to rest. Yes, weights, not a scale, gravity is constant.

Dan, what kind of weight do you get for your Glock's trigger pull?

Bill

[Dan Sierpina]

Bill,

I've always measure the trigger at the curve, where the weights would naturally come to rest. Yes, weights, not a scale, gravity is constant.

Dan, what kind of weight do you get for your Glock's trigger pull?

Bill

I'm sorry, I don't have a Glock. My M&P is 3 3/4 pounds though.

[Flexmoney]

Bill, I think it is "anything goes", when looking to measure a Glock trigger. (probably the same with any trigger)

It's not really about getting an accurate and standard measure. It's about making a claim as to how low the trigger weight is.

[ChuckS]

Bill, I think it is "anything goes", when looking to measure a Glock trigger. (probably the same with any trigger)

It's not really about getting an accurate and standard measure. It's about making a claim as to how low the trigger weight is.

If I was selling a trigger kit, I would measure as close to the tip of the trigger as possible. If my trigger was getting checked at an IPSC match, I would want the measurement made as close as possible to the top of the trigger. Lever arm physics

ETA: The IPSC rules cover where the measurement should be made

Edited November 10, 2009 by ChuckS

[racerba]

Your weight seems low for a stock Glock. You must have stock components. My 3.5# connector measures in at approx 6#. The way IPSC weighs the gun is by hanging weights and lifting the gun straight up.

[Flexmoney]

Note: threads merged.

- Mod Squad