Extra Blades for the Muzzy MX-4 Muzzy took all the legendary components of the Muzzy design and incorporated them in the design of the MX-4. The MX-4 is a 4-blade, 100 grain, short profile broadhead with a cutting diameter of 1.125 (1/8 wider than the standard 4-blade 100 grain broadhead. Muzzy, as an extra feature, designed the MX-4 blades to be .005 thicker than the standard Muzzy broadhead, (.025 vs. .020).