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My Home Brew 500gm Trigger Weight

Posted: Fri Oct 24, 2008 12:39 pm
by Oz
I was curious and found a quick way to test it for myself.

Two tins of RWS Hobby Pellets weight just under 500 grams. I added a third nearly empty tin (containing about 11 pellets) along with the piece of coat hanger and the piece of string... 531 grams.
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There it is. I'm adjusted and now my trigger just barely holds 531 grams.
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Oz

Posted: Fri Oct 24, 2008 5:05 pm
by ausdiver99
Neat home solution, well done!

The only problem may lie with the part of the wire hanger resting on the trigger, it needs to be a knife edge (8.4.2.6.4) but I can't see from the photo whether you have filed it. With the extra 31 gm you probably will not have issues when you front up to EC as there is plenty of margin.

Great to see you added that extra 31 gm. Its amazing how many competitors arrive at EC with firearms that just lift the required weight. A cold morning or a bit of gunk in the mechanism & bingo many won't lift the weight.

For the life of me I can't understand why they give themselves the grief before a match with marginal pistols!

Posted: Fri Oct 24, 2008 6:00 pm
by GaryN
I had just the situation you described.
I set my trigger to 525 grams, 25 gram buffer...so I thought.
I "barely" made the trigger weight test.
The tester thought a combination of things may be the cause; temperature (range was 25+F hotter than my home), my "home made" weight rig, my scale (how accurate is it?).

Posted: Sun Oct 26, 2008 5:07 pm
by Oz
ausdiver99 wrote:Neat home solution, well done!

The only problem may lie with the part of the wire hanger resting on the trigger, it needs to be a knife edge (8.4.2.6.4) but I can't see from the photo whether you have filed it. With the extra 31 gm you probably will not have issues when you front up to EC as there is plenty of margin.

Great to see you added that extra 31 gm. Its amazing how many competitors arrive at EC with firearms that just lift the required weight. A cold morning or a bit of gunk in the mechanism & bingo many won't lift the weight.

For the life of me I can't understand why they give themselves the grief before a match with marginal pistols!
Thanks, it seems to work well. Thanks for pointing up the knife edge sitting on the trigger! I didn't read that part. It's certainly something to consider. Hopefully the extra 31 grams will ensure it qualifies since I didn't go to the effort of that detail!

Oz

Posted: Sun Oct 26, 2008 5:09 pm
by Oz
GaryN wrote:I had just the situation you described.
I set my trigger to 525 grams, 25 gram buffer...so I thought.
I "barely" made the trigger weight test.
The tester thought a combination of things may be the cause; temperature (range was 25+F hotter than my home), my "home made" weight rig, my scale (how accurate is it?).
Nothing like putting someone at ease ;) When I did my adjustment it was moderately cool. I hadn't considered temperature creating any significant change, but anything's possible.

Posted: Sun Oct 26, 2008 6:35 pm
by ColinC
Oz you disappoint me! When I read that you had a home brew trigger weight checker I was expecting a bottle of home brew with so many sips out of it to measure the weight. Using pellets seems so much more civilized anyhow.

Regards the trigger weight. Can I suggest that you creep it up to more like 560 grams. Believe me, you will not feel the difference between 530 and 560 after a couple of shots.
To me 531 is far too close to the margin. My Morini which failed on an official set of weights at an open shoot when it was a chilly morning (not even a frost) passed easily with no adjustment after I slipped it under my jumper for 10 minutes. Since I upped the weight by a couple of 20 cent coins, I have not had any problems.

I would think that in the US and Canada, where it gets a lot colder than here in Oz, having a finely set trigger is just asking for problems at gun check.
Colin

Posted: Mon Oct 27, 2008 11:10 am
by ausdiver99
Now would I have done that to you Colin? At least I know who to go to when I need $1 worth of 20c coins for Oakleigh's coke machine!

Three Australian 20c coins = 34 gm (approx) btw for those who want to use the coin trick.

Posted: Mon Oct 27, 2008 11:32 am
by Oz
ColinC wrote:Oz you disappoint me! When I read that you had a home brew trigger weight checker I was expecting a bottle of home brew with so many sips out of it to measure the weight. Using pellets seems so much more civilized anyhow.

Regards the trigger weight. Can I suggest that you creep it up to more like 560 grams. Believe me, you will not feel the difference between 530 and 560 after a couple of shots.
To me 531 is far too close to the margin. My Morini which failed on an official set of weights at an open shoot when it was a chilly morning (not even a frost) passed easily with no adjustment after I slipped it under my jumper for 10 minutes. Since I upped the weight by a couple of 20 cent coins, I have not had any problems.

I would think that in the US and Canada, where it gets a lot colder than here in Oz, having a finely set trigger is just asking for problems at gun check.
Colin
LOL... I think the title is a bit deceptive. I apologize ;) Your initial thinking does sound like a potentially interesting option! Get to work on it and report back.

From everything everyone is saying, I think 560 is a better and safer option as well. Will do.

Posted: Mon Oct 27, 2008 3:09 pm
by Shooting Kiwi
When trigger weight is tested, where along the trigger blade should the weight hanger be placed (how far from the pivot, how much leverage)? In what attitude is the gun to be held (ie barrel vertical, or is it not specified?)?

Posted: Mon Oct 27, 2008 3:28 pm
by Oz
Shooting Kiwi wrote:When trigger weight is tested, where along the trigger blade should the weight hanger be placed (how far from the pivot, how much leverage)? In what attitude is the gun to be held (ie barrel vertical, or is it not specified?)?
The rules book is pretty specific on this stuff. The barrel is held by hand, precisely verticle to the ground. (Perfectly straight up and down.)

The weight hanging device is placed in the middle of the trigger. This seems harder to define, but again, the rule book has some illustrations to show all this.

Posted: Mon Oct 27, 2008 3:29 pm
by Spencer
8.4.2.6

Posted: Mon Oct 27, 2008 3:33 pm
by David Levene
Shooting Kiwi wrote:When trigger weight is tested, where along the trigger blade should the weight hanger be placed (how far from the pivot, how much leverage)? In what attitude is the gun to be held (ie barrel vertical, or is it not specified?)?
ISSF rule 8.4.2.6.1 begins "The weight of the trigger pull must be measured, with the test weight suspended near the middle of the trigger (see illustrations) and the barrel held vertically. The weight must be placed on a horizontal surface and lifted."

You'll have to look at rule 8.4.2.6.4 online as I can't work out how to copy the diagrams to here.

edit note: The diagrams don't even appear if you use the above link so you might have to look at the full rules, page 355 of 563, numbered as page 351 (beware, approximately 10MB).

Posted: Mon Oct 27, 2008 3:54 pm
by Mark Briggs
Trigger testing is a hotly debated topic at some matches. As a general rule, the pistol should be held vertically. The trigger weight should be in the groove in the trigger if one is supplied, otherwise as close to centre of the trigger shoe as possible is generally what seems to be the "local application" of the rules.

On the topic of triggers and homebrew testers... I've made up my own tester using a 1/4" brass rod, pellet tins filled with melted lead, and a few big penny washers. The washers weigh about 9 grams each so they allow me to add incremental weight above the 500gram, 1000gram and 1360 gram weights which are achieved by having one, two or three lumps of lead attached to the brass rod. The rod is filed to a knife edge where it engages the trigger so it complies with the current ISSF trigger weight spec.

The net result is that I'm able to set my triggers to the desired weight by using the baseline weight (eg 500grams) then adding a sufficient number of washers to provide some buffer. My technique so far has been to set up air pistols so they will lift at least two additional washers, so 518grams, but not a third washer. My triggers have not failed trigger testing at matches in quite some time, despite their having travelled by air and car, and having gone through considerable temperature change. The only time they fail is when the person doing the test doesn't know what they're doing. When this happens I educate the person doing the testing since JERKING the gun upwards is NOT a valid trigger weight test. You'd be surprised at the number of officials who don't know how to properly test a trigger!

Posted: Mon Oct 27, 2008 5:26 pm
by Spencer
There is a deal of information on ISSF trigger weight testing readily available in section 3 of the ISSF Manual for Juries and Range Officers for Pistol, available as a PDF at http://www.issf-sports.org/documents/sh ... l_2006.pdf or the zipped PDF at http://www.issf-sports.org/documents/sh ... l_2006.zip

Spencer