volquatzen , mag research, and remmy are the only ones. the volquartzen will be reliable, and safe, out of the box, so will the mag reasearch. the remmy will not be, but can be made so, if one does the rail job found under the stickies, under the remmington thread, over on rimfirecentral.com. otherwise, it could fire out of battery, this is only a prob for the semi's though.