Trigger pull scale

[mforsta]

Tell me if this makes sense when checking a rifle trigger. If I check a trigger weight with action out of the stock I get 2.5-2.75 lbs. when I put the gun back together I get 3.25 lbs. Could the difference be the way the scale has to be pulled when the action is in the stock?

 

[JBP55]

I would only be interested in the trigger pull weight when the firearm is fully assembled and get a 10 pull average.

 

[John_]

Also keep in mind a trigger is a lever. So the farther away from the trigger pivot pin, the lighter the pull. Very slight variances but measurable. Use your gauge contact shoe in the same spot on the trigger every time. Imitate your finger contact location if say you were bench firing the weapon.

Also if you are holding the trigger action in your hand and using your other hand with the gauge, it could account for the slight differences. You want the gauge shoe contacting the trigger is the same spot, and pull at the same angle every time.
Deviation in pull angles can affect the reading very slightly.

If you want to measure pull out of the weapon, put the trigger assembly in a rigid bench vise with brass or wood strip protectors. This will make measurements more consistent. Like if you are doing tuning, spring changes, or polishing before weapon final re-assembly. Perhaps you are using a vice already.

The biggest variable imo is placing the gauge contact shoe in the same spot on the trigger itself every measurement, and make a nice smooth 180 degree pull away from the trigger face.

 

[John_]

Oh and make at least 5 clean pulls/measurements and then average them. My Wheeler pull gauge will average the pulls automatically.

 

[mforsta]

That’s what I figured was happening. Just a slightly different pull angle is changing the trigger pull weight. This is on a hunting rifle so I’m ok with a 1/4 pound difference. I’m comfortable with a 2 3/4-3 lb trigger on a hunting rifle.

 

[John_]

That’s what I figured was happening. Just a slightly different pull angle is changing the trigger pull weight. This is on a hunting rifle so I’m ok with a 1/4 pound difference. I’m comfortable with a 2 3/4-3 lb trigger on a hunting rifle.

10-4. Some rifles have a trigger cassette you can work on or measure away from the assembled rifle. Yes i agree, that weight is fine on a hunting rifle.

Another example is an AR-15 rifle or pistol. You don't need both halves assembled to accurately measure trigger pull. You can do it with only the lower half. The upper half has zero influence on the trigger action or pull. Just don't let the hammer smack the receiver/bolt hold open lever time and time again. I use either my finger to cushion, or a piece of split rubber hose to stop the metal to metal contact. When the hammer travels fully forward after release.

 

[Blackhawk]

Interesting factoid to illustrate trigger position with the gauge as talked about above:

I have a Winchester 190 .22 rifle, has a tube magazine. When pulling the trigger straight back toward the buttstock the trigger pull is 6 lb 6 oz. When pressing up on the trigger, toward the action, it will trip the trigger at 4 lb 2 oz. Pull direction definitely makes a difference.

 

[John_]

wanted to add BC i'm somewhat OCD a 1911 trigger is not a lever, no pivot point. Just a simple mechanical push to break the sear. John Browning was a mechanical and design genius.

 

[Bam Bam]

Tell me if this makes sense when checking a rifle trigger. If I check a trigger weight with action out of the stock I get 2.5-2.75 lbs. when I put the gun back together I get 3.25 lbs. Could the difference be the way the scale has to be pulled when the action is in the stock?

What type of gauge are you using? I've seen the old "analog" mechanical scale type read inconsistent before which prompted me to buy a digital gauge. I'm in you area if you need to try it and compare it to your gauge.