I made my own using the UTG-#2 barrel mount. I can't really say it was big improvement in 3 or 5 shot groups from the bench. It shot about 2 moa @ 100 yards in stock configuration and it might be a tick better now. But the big improvement was a 20 round quick fire at 100 yards, from a good rest it will put all 20 in a baseball size target, it would not in stock configuration after about 10 rounds it would start walking of target, not bad but say in a 10 inch circle. I'm still tinkering with strut tubes in various diameters. I like the strut it seems to settle the harmonics and act as heat sink to a certain degree.