I have a Luppy in an Armalite one-piece scope mount and a TA11 in a TA51 as well as a KAC 300m BUIS.  As everyone knows, all of these mount to the flattop by tightening a thumbscrew or in the case of the KAC a straight slot screw.

Given these mounts are tightened the same within say a 1/2 - 3/4 turn should they return to zero each time they are removed and remounted?

Thanks for the time.

My armalite always returned to zero for me.

TXL

General rule of thumb (no pun intended) is thumbscrew mounts do not return to zero.

That said, if it's a well made mount and you mount is consistently every time, it should (or atleast be very close).

Always push the mount forward in it's slot as you tighten the thumbscrews.  Tighten the thumbscrews in the same order every time (front then back or vise-versa).  Tighten them the same amount every time.  I usually tighten them by hand tight and then use a tool (coin, screwdriver, whatever) to tighten them another 1/4-1/2 (depends on thread size, sometimes 1/4 turn doesn't do much) turn.  If your thumbscrews are tight at 1/4 turn extra, always tighten them 1/4 more.  Same with 1/2 turn, just don't tighten them 1/4 turn one time and 1/2 another.  Consistency is the key.

Quoted: I have a Luppy in an Armalite one-piece scope mount and a TA11 in a TA51 as well as a KAC 300m BUIS.  As everyone knows, all of these mount to the flattop by tightening a thumbscrew or in the case of the KAC a straight slot screw. Given these mounts are tightened the same within say a 1/2 - 3/4 turn should they return to zero each time they are removed and remounted? Thanks for the time.

My 3 TA51s (2-TA11E and 1-TA31F)  are sitting in my parts drawer. I ended up replacing them with a LaRue mount. The LaRue was quicker to remove and reinstall. YMMV. If someone is interested, the 3 TA51s are available.