Just wanted to bump this a bit. After proper tuning, and finding a sight I really like (Apex Atomic 4-pin), I'm stacking arrows with this thing. I shot 14 arrows at my Yellow-Jacket target today. Except for 2 flyers (bad fletching job on my part), 12 of the 14 arrows were touching. Flat out, if you do your part, this thing will improve your shooting.
Forgot to add I was shooting at 35 yards, with a mixture of Trophy Ridge Blast 400 and Carbon Force Radial X Weave arrows, and I wasn't shooting at the same bullseye every time (with 14 arrows it would stand to reason they'd all be touching
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