Trying to tune carbons to my new Mojostik 52# @ 28". And I am confused...
First tried 500 spine with 100gr. inserts and 200gr points on 29.5" arrows..This seemed to work OK but not perfect (flew better with 175gr points, as per my first pics here a couple of weeks ago.
Well I wanted to try the 400 spine MFX shafts I have laying around. These are cut 28.75-29" (stiffer still right) and I already had standard inserts glued in, so I tried 200gr. points and these seem to fly as good if not better than before. Was I doing it all wrong? Arrow weight is at 535-540gr. total, and I'd like to see 600gr. 27" Whippersnipper line weights about 28-30gr. so 2 strands should do it, but that throws off my high FOC. Can I remove the standrad inserts and re-glue some 50gr. brass inserts in there? Season's getting close so I gotta get this figured out.
Thanks
so you have ~300grs in a .500 spine arrow and roughly ~215grs in a .400 spine arrow for 52#s. The .500's are definately underspined, if you would switch to a 100gr or 125gr point you'll see an improvement, but you'll lose your FOC a bit.
The .400spine might be on the verge of too stiff, but that may help with broadheads. If you loose the tip weight, it'll definately go too stiff.
To bump up the weight, you'll need to add mass to the shaft through weight tubes or some kind of filler that won't effect the overall spine, but as long as you keep at least 18-20%FOC I don't think you'll have any issues with flight.
You can remove an insert by taking a drill bit about the same size as the inner diameter of the shaft, place it in the nock end flatside toward the insert, and swinging the arrow down firmly toward the ground - but make sure to put a pillowcase over the insert end - it'll pop out.
Chris
Wihill, thanks for the input.