jonbearman said:Its called ratchet by shilen,5r by kreiger and remington and others,it is really canted land rifling.It is supposed to have less drag and cleans easier and is fairly popular with alot of shooters.I have a shilen and it broke in in 3 shots and cleans really easy for me.Polygonal rifling is way different and glock made it popular along with H&K and other companys in europe and now here.