I ordered a set of three of these because I wanted to try the +1 extensions from impact. Besides the fact of totally munging up one of my stock mag springs during +1 install due to carelessness on my part, I felt the extra round needed extra spring power. I figured going from 6 to 7 rounds is 7/6 = 1.167 in terms of ballpark spring power wanted with 7, and the +10% is close enough for me. If they made a +16% spring I'd have tried that
They fit and work fine, but are probably not needed for stock 6 rounders. I mean I have never had a mag related failure ever with any of my ruger mags, 4 of them over 2000 rounds, roughly 333 each = 55+ mag load/dumps each.