LOP Saiga 7.62 stock shortening

[prsabordo]

Hey everyone, ive been doing my research and have been coming up on good information but i just dont know which is the correct method for determining LOP and how to shorten a stock? The LOP on my saiga is too long and its a synthetic stock but i bought a donor stock to try and modify. So to my understanding and correct me if im wrong but to measure LOP, you measure the inside of your arm starting at the bend of your elbow at the base of your bicep while your arm is bent at a 90 degree angle, then measure out to your trigger finger as if its shaped to pull the trigger? Also i read that when cutting a stock to LOP, its a 4:1 ratio. So for example, if im a 12 1/2 inch LOP and the stock is 13 1/2, to reduce the LOP to 12 1/2 i would have to cut the stock 1/4 of an inch? Or is it 1:1 ratio? Sorry for the noob questions but i want to make sure i do this right and i appreciate the help. Another question, does determining the pitch of the stock on a rifle the same as determining the pitch as if it were a shotgun/should the rifle stock pitch be 90 degrees?

[kcstott]

Length of pull is 1:1 ratio look at the brownels LOP jig it is a direct measurement.

Pitch is the angle of the recoil pad in relation to the bore axis.
Typical pitch on a rifle is 3 degrees negative pitch. Negative pitch is an angle that is less the 90 degrees as measured from recoil pad to bore axis. Positive pitch is any angle grater then 90 degrees

Pitch angle is determined by the shape of your shoulder.