Reducing trigger pull

[ernie]

Not that I'm doing this, but if we were working on a Ruger VaQuero how could I determine about how many coils of the factory spring I would need to remove to take it from a 12 lbs trigger to a 7 or 8 lb.? I thought of counting the coils and dividing into 12 but that doesn't seem to work. Any thoughts?

[DnPRK]

Cutting coils is the wrong way to reduce spring force. The proper method is to reduce spring wire diameter. Go to gunsprings.com and order a reduced power trigger spring for $3.49

[Jim Watson]

If you have a Vaquero with a 12 lb trigger pull, it may need more than a limber spring kit. Like a visit to a gunsmith or a return to the factory.

[ernie]

Thanks guys, you are right. But I'm trying to research an answer to a test question. I know the correct way would be to replace the spring but they want to know if we did cut, how much of the spring coils I would have to take off

[Old Grump]

rate = ( wireDia^4 * 1470000 ) / ( coilDia^3 * numCoils )

Formula doesn't work if you have a progressive coil or a flat spring and you didn't say if you are going to stretch the spring out to the original working length or leave it short by the number of coils you cut off. I'm glad I'm not taking this test.

[ernie]

Good points. The way the question reads is "Cowboy shooters like to take the 12 pound triggers of their Ruger Vaqueros down closer to 7 or 8. About how many coils of the factory spring would need to be removed to achieve this 3 to 4 pound reduction"

[Jim Watson]

Sorry, I am too many years away from my non-mechanical engineers' one class in engineering mechanics to do a calculation based on spring load and spring rate for you.

But the question is nonsense.
As I said, a normal Vaquero will not have a 12 lb trigger pull and a CAS competitor would not settle for a 7 or 8 lb trigger pull.
And 12 to 7 or 8 is not a 3 or 4 lb reduction, it is a 4 or 5 lb reduction. If the questioner can't do arithmetic, how can he expect you to do more complex calculations?