The Umerex Colt (Walther) 22 cals, the Smith and Wesson M&P 22 cals and several other military look a like 22 cals have metal frames (receivers) barrels, and trigger housings......The stocks, grips, and fore guards are polymers......There may be other polymer parts, but the basic rifles are made of metals
The Colts and S&Ws are well made and dedicated 22 cal rifles and not cobbled together........I have both and really enjoy them...
I cannot see heat as a problem any more so than with any other types of rifles......Sag???..Even if the plastic did "sag" it would not cause the receiver and barrel to deform.....None of mine have sagged ;-)
Last edited by dan01; 06-21-2012 at 04:58 PM.