There are 2 types of accustock recoil lugs. The first generation being similar to the axis line of rifles. The second gen is thinner around the sides.

Savage factory recoil lugs have a tang protruding out to fit in the recess of the receiver to align themselves.

I have Hollands recoil lugs that have a pin, and the pin is very thin and is useless in aligning the lug.

SSS recoil lugs have a thick pin that fits the the receiver recess, aiding their alignment.