I had a Mossberg MVP-LC .223/556 chassis rifle that was a 1-7 twist and a huge long throat, would take anything I could fit in it, really liked the Sierra 77gr tipped match king's. While the gun was awesome the factory trigger has some safety issues and I had to swap it out with a Timney. You would pull the trigger to fire a round and it would "click" but no bang, let off and it would fire,... scary! Guy at the range fell in love with it so I moved it on.