Trigger Finger Position and Pull Weight

jbshooter · Post by **jbshooter** » Sat May 28, 2011 7:11 pm

The Morini air pistol has a groove in the face of the trigger blade to facilitate trigger weight testing. Could a shooter be deemed to have broken any rules if their finger naturally comes to rest on the bottom end of the trigger blade and they apply their shot release pressure there, where the total weight to release the shot could be considerably less.

Greg Derr · Post by **Greg Derr** » Sat May 28, 2011 7:44 pm

david alaways · Post by **david alaways** » Sat May 28, 2011 8:29 pm

Tried that position for a couple weeks, worked great for 2 days. I figured I would at the least I know where my finger was going to be (in the same spot) everytime.

Dr. Jim · Post by **Dr. Jim** » Sun May 29, 2011 3:58 pm

Actually you have to be careful about those grooves. The ones on Hammerli AP40 triggers is not located at the "centre of the trigger curve" and thus is not the legal point for testing the trigger. I have had AP40 triggers fail at the Canadian Nationals because the competitor assumed that Hammerli was correct and not the rule book.

Cheers --- Dr Jim

jbshooter · Post by **jbshooter** » Sun May 29, 2011 7:21 pm

I raised the issue because I manufactured a new shoe for my Morini, similar to the Steyr shoe in that you could slide it up and down to suit finger placement. The centre of the shoe was 3-4mm lower than the groove on the Morini trigger blade and I had to increase the spring tension considerably to meet the 500g weight test. The other issue was that the radius of the groove was 3-4mm lower than the mid-point of the trigger length, which made it difficult to apply the rules or interpretting them in a way that a judge could apply or abide by them eg should the judge hang the weight in the centre of the curve or the mid-point of the trigger length. I estimated a 200-300g difference between the two adjustments.

Dr. Jim · Post by **Dr. Jim** » Mon May 30, 2011 9:55 am

jbshooter wrote:..... should the judge hang the weight in the centre of the curve or the mid-point of the trigger length. I estimated a 200-300g difference between the two adjustments.

In the new rules, my interpretation is that the centre of the curve is the point to rest the trigger weight bar. Indeed, for practical use, this point is where the shooter will be applying pressure and appears to me to be the intended test point. One defect of the old "roller" was that if the trigger had a large amount of take-up, the roller could move down to the tip of the trigger and provide a false reading - I suspect this was the reason behind the change to the knife-edge system.

Cheers --- Dr Jim

lastman · Post by **lastman** » Wed Jun 01, 2011 1:32 am

There would be no issue with doing that.

However there may be an issue when you press the trigger.

If you press the trigger from the bottom of the trigger blade you are more likely to pull the shot down as you release the shot.

If you are pressing from the bottom you're probably only press about 20g less. The difference will be very minimal.

You should continue trying to press more deliberately onto the centre of the trigger blade.

Good luck