You don't use a bushing. The nock should press right in. The only bushing I've seen used in most common sized carbon shafts is the ACC-60 bushings when planning on using G-nocks, which isn't a bad move anyway.
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Martin Silver Star Shooter
UBP Life Member
PSAA Life Member
Worldwide Scuba Diver
I know that the standard nocks press in but for 3-d I wanted to try using the bushing so that when arrows nock into each other in the target, it will not damage the end of the arrow. I lost a lot of arrows last year with splintered ends. I figured that the bushing might protect the shaft better.
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2008 HNI Bow Contest Team #35 Top Pin Predators