What does that infer 'blocked or pinned to 10 rounds'??? Why would you buy a 20 round mag that only holds 10? I don't get that.
S&W M&P15-22 Magazine, .22 LR, 10/25 RoundsThe S&W M&P15-22 Magazine hold 25 Rounds of .22 Long Rifle ammunition and is made of black polymer. Blocked to 10 rounds.Fits:S&W M&P15-22...northernrepublicmagazine.com