Heads are interchangeable. For the most part, the different heads for crossbows are a marketing ploy. The shafts are larger diameter and some heads like the Swhacker can hit the shaft on openning. No problem with most heads in that respect. Some super fast crossbows can cause some mechanical heads to open on firing. This can be controlled with another band (or a thicker one) to keep blades from openning prematurely. I shoot Swhackers in my crossbow and simply take a dremel to the fins and remove a little material so that they dont hit the shaft. Fixed blade heads work without issue on either bow.