making a "bump"" die

porthos

Active Member
going to make some bump dies to uniform cast bullets. the questions that i have concern reaming. i'm to finish ream in the lathe. what size drill should i use before reaming (30 cal. how much smaller should the drill be) ?? hand reamers have a taper ; would a hand reamer be better than a chucking reamer? any advice before i start?
 

smokeywolf

Well-Known Member
porthos, use your chucking reamer. Drill .008" to .012" under your reamer size. Use plenty of cutting oil, flood coolant or a spray mister. A little lower surface feet per minute for reaming than for drilling.