Bbl heat mirage can definitely be a problem...but couldn't you put a mirage cover on the can, and a mirage shield over the bbl to keep it from interfering with the image through the scope? The rifle I had built for BR VS is a 6 Dasher on a BAT 3L with a 28" Bartlein hvy Palma 1-7.8tw. I now have a Sightron SV 10-50x60 ED scope on it, and on a calm day, bbl mirage would certainly be an issue, but an Armageddon Gear cover on the Ultra 7 does a decent job of keeping heat off the can from messing with me. But I still need a mirage tape for the barrel...Give it 8-10 sighters and a 20 shot record string. I don't care what kind of 'sock' youve got on it, the mirage is a killer. Put me in the solid 'NO' camp on suppressors in F-class. I'm all for hearing protection but I wouldn't want it for F-Class. I have used one on a 'F-practical' rifle shooting with F-class targets/scoring at the local 600yd. range. Definitely nice to have everyone on the line shooting suppressed, but the mirage coming from the muzzle end near the end of the string was a big problem.