gun isa ruger m77- ss factory bbl- 140 gr. hornady sst - IMR 7828 powder- low end of load scale- will heat affect zero ? it will hold at 100 yds and 200 yds but is moving around out past 200- temp has been over 100 dergees for yhe last couple of weeks

yes sir heat dose do the nasty , seen it done it , IT WILL DO U IN !