i had one and it worked great. but when i first installed it, it touched the gas block. so when the barrel heated up, it did some pretty bad stringing. like four inches from cold barrel point of impact, to hot barrel point of impact. if you fired two shots real quick it would put them together. after i figured out what was happening, i fitted it corectly and yes, it did help with accuracy with many loads. even loads that i had tryed and rejected, were much better. shooting one inch groups was no problem at all, and a few approached the half inch. for the price, i,d check around for a heavy barrel. accuracy international has them but there pricey! good luck.
by the way, i sold mine because i couldn,t get it to stop chewing up my brass. oh well.
bobby olson