We have been informed that the black limb bolts were aluminium. Not having seen any of the issues ourselves, so we can only speculate. longer limbs would achive higher leverage ratios on any bolt, but this could make the bolts snap as alumunim has a fategue life much shorter then steel. This is the only issue we have heard of, and rumour has it that our limbs were to blame from what we heard.. I beleave that the some of the guys here on
AIUK can elaborate more than we can.
This might have been a bigger issue if shortcuts were taken and the bolts were adjusted while the bow was strung. meaning a greater chance of more stress being added to the weaker aluminum bolt.
if thats not the issue then its a new one to us...
What we can say is that the forces applied to our limb butts are just the same as any other limb, as 40lbs on the same standard fitting is still 40lbs. and there are plenty of hoyt riser/border limbs archers out there shooting our 72" limbs with no problems and the 2 instances that we heard of the black bolts snapping were dealt with by the respective retailers, and we never saw the problem 1st hand.