It is pretty easy to check the firing spring poundage. I glued a thin pad to a small (3" x 2.5") block of wood with a hole in the middle big enough for the firing pin to fit in but small enough that the flat part can rest on it. (I don't know what the flat part is called) Take the firing pin out of the bolt (leave the spring and shroud on). The block of wood is on the scale and the firing pin is vertical on top of the block of wood. Zero the scale then push down on the back of the firing pin and read the scale until it "breaks" You'll want to do it several times to get a decent average. If it is low - then you need to replace your spring.
The question is - what is low? Based on recommendations of others - I have BAT 3 Lug(s) and the spring should be around 20 - 24 lbs. BAT's light spring for the 3 lug is around 19 lbs and their heavy spring is around 24 lbs. I do not know if that is the recommended poundage for other actions or not.
Last year - I was shooting pretty good with my LV rifle, but stinking the place up with my HV. I could not figure out what was going on until I tested my spring pressure. If I remember correctly, It was down around 14. I do not understand the science of it - but I am told that causes inconsistent firing - which is bad juju.
Hope this helps. Sorry my terminology is not very good. I will look up the correct terms and also double check my numbers to make sure they are correct and fix this later.
Note: numbers are correct - terminology still is bad.
Stanley