Yes it "should" as Picatinny is MILSPEC and WEAVER is not. The rule of thumb is Piacatinny rails will accept weaver mounts, but weaver rails will not accept Picatinny mounts,also consider pistol rails are shorter than rifle rails...so spacing could be a consideration. I have a weaver mount scope on my ar's picatinny rails,fit perfectly. The light looks a bit large for a handgun. Remember Walmart has a return policy,ask before buying. If it does not fit return it !