Greatly improves the dispensing of Coors products. Reduces the impact at the back of the plunger in the faucet. You may be better off replacing the shank with a quarter inch one. Or, invest in the bit and drill guide. If you try to free hand the bore, you better be steady! No need to go to far. 3/8" back should be sufficient. Leave the shank in the tower and attach the guide to the faucet collar. Be sure the bit does not go to far. There are tapered bits available at hardware stores that probably would due the job. If your shank is brass, this does not take much effort. Stainless shanks will take more effort and slower RPM with cooling. Use the beer to flush out the shavings. Lightly push down on the coupler handle as you turn the collar with your other hand.
Wear safety glasses!
Scott Zuhse, Instructor
Micro Matic Dispense Institute