The O-ring trick....

[TM7]

I've heard about the O-ring trick and I assume this goes ard the forestock sscrew mounting stud. But what is the idea here and how does one do this most effectively? I bet it's necessary for my new 223 UV!

...................TM7

[quickdtoo]

The "O"ring just floats the barrel so contact is limited to the the barrel stub only.  A 9/16"ODx3/8"IDx3/32" thick "O"ring on the barrel stud will usually work. Tighten the forend screw just snug, don't compress the "O"ring.

[quickdtoo]

The headspacing is controlled by the underlug and latch system. The forend only affects the action when opening and closing, not once it's closed. But the fit can affect barrel harmonics and from what everything I've learned here, the best fit is just tight enough to not wiggle. If the fit is too tight for opening and closing easily, I either put a thinner forend spacer on the forend or remove a little material from the spacer to make it thinner. Sand the flat of the spacer with it removed from the forend.