a replaceable cutter shell mounted over said rolling cutter shell, said replaceable cutter shell having an annular tapered inner surface that mates with {TAIL ~ said annular external surface} of said rolling cutter shell, said annular tapered inner surface having a slope at {HEAD ~ an angle} within the range of substantially 2° to substantially 40°; and 
a replaceable cutter shell mounted over said rolling cutter shell , said replaceable cutter shell having an annular tapered inner surface that mates with { TAIL ~ said annular external surface } of said rolling cutter shell , said annular tapered inner surface having a slope at { HEAD ~ an angle } within the range of substantially 2 ° to substantially 40 ° ; and
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH