i have a horton blackhawk. 200lb draw. 300+fps. i shoot lightning strike alum arrows tipped with monotec G5 heads 100 grain.and use a multirange horton scope. ive been shooting this bow for 3+yrs and have never had a prom..now after i sighted it in this season. my 10 and 20 yd lines r dead on but my 30 is shootin bout 4 inchs high.. i never had this problem before all past seasons the line were perfect out to 50 yds but now they r off.. could it be the scope or is it more than likely just me??? btw. my last 9 shots were from a rest