Can someone explain why this increases LOP for some and not for others? That’s a real head scratcher. Is it thicker than OEM or not?
Psychological. It's something new on an already comfortable rifle and the body hasn't gotten use it. Very similar to a newbie who is given some reloads. Now the loads are the same as some factory rounds, but those factory Rem corloks with that buggered up lead tip doesn't look as cool as that sleek Berger VLD. The berger could have been loaded with much less thump, but the mind has already made up its choice before you pulled the trigger.
Similar situation here. If the length of pull is 1/4" or even 1/2" more or less, it just something to get use to. I have the Airtechs on both of mine and when shouldered, you can actually feel it give alittle. Not as firm against my shoulder. Maybe thats what they feel.