High flow bolt, also the bolt is cupped which might help accuracy.
since the bolt is cupped, it is alittle sharper and could dent/chop balls.
I have been using my BMW bolt fof 2 years now. Before then I owned a GusDaDog delrin bolt. Both performed the same. The BMW bolt is easy to buy since BEOG Super store sells it, and has an online order form. Its the easiest bolt to buy out of all RM bolts For 25 bucks you cant go wrong.
25 bucks is a good deal for this bolt, it helps with the overall performance of the Rainmaker. Check out more reviews of this at http://rainmaker.flipty.com the RMOG.