Abstract: Apparatus for testing the flexibility of ammunition link belts by folding the belt longitudinally back on itself in both directions, and also by twisting it about its length. The belt forms a loop in passing between a set of feed sprockets; the radius of the loop increases in the event that any of the links bind and cannot pivot freely on one another, causing the belt to engage a switch which stops the feeding motion of the sprockets. The belt is twisted 180.degree. in passing to a second set of feed sprockets, between which the belt forms a second loop, and engages a second stop switch if the links bind in their inverted positions.