I'm not too sure about Federal's math, but this new stuff is as effective as the new Winchester or HeviShot, if your gun likes it. In general, it patterns well with very little constriction. It does best with about 50 points of constriction, which with a Remington barrel at .729 would be a turkey choke measuring .679. Remington's older turkey chokes are .665 and .660.
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Author of Tennessee Whitetails. Proceeds from every sale go to a good cause... keeping my boys supplied with bullets, powder and primers.