Today while at the range shooting my new to me Rem 700 in .223, one of the old timers told me I should try using a custom tailored OAL to improve my groups. I was shooting Sierra 52 grain HPBT Match Kings that I was trying different powder weight charges with. I had settled on one particular charge weight because I seemed to get better groups with it than the other weights. Anyway, the guy said I should measure the chamber and try setting my OAL about .005-.010" off the leade and then back it up in small increments to find the optimum length. Will this really make much of a difference? Fact is I was making basically one hole at 100 yards with the load I had settled on. If I go out to say 200 or 300 yards would this make a noticeable difference? For point of reference I did measure the length with a dummy round when I got home and with my OAL I am sittiing about .095" off the leade right now.