3 under and tuning question

[m midd]

I recently switched from split finger to 3 under and i am having trouble getting tuned. My arrows are contacting the outside of my shelf and i cant seem to tune it out. Ive went up and down with nock and brace height with now real change. I can shoot the same arrow split finger with no ill effects.. Im shooting a Tomahawk 53# @ 28  and surewood 55-60 spine arrows 29 1/2" with 5" High back shields... Any Ideas?

[McDave]

Generally the nock point needs to be raised when you switch from split to 3 under.  The minimum nock point for any of my bows that I shoot 3 under is 5/8".  Most of them shoot best around a 3/4" nock point, and a couple like it even higher, around 7/8".  If the nock point is too low you will get a bounce off the shelf.

[nschlag]

what McDave said

[raghorns]

Yeah...it may look ridiculous, but keep moving it up until you get good flight.

[m midd]

Whats odd is my arrow flight is perfect..Ive shot it through paper at 5 and 10 yards with a perfect bullet hole.with my nock at 3/4" it shows nock high but i still get good flight .  i still get a tink sound and the mark on my arrow.. I am in the process of building a set of 5# lighter spine arrows and messing with my strike plate.

[m midd]

I am gonna raise the nock higher before i mess with the plate though.