I have one in a base NXT shocker with a rhino spring and love it. It still has a lip at the back that needs removed to work with a spring.
I get 8 pods and a hopper out of one 68/4500. Those are literally the only non-stock parts in the gun.
It's very similar to the pooty bolt, except it has a slight concave bolt face and costs $25 less! I paid $25 on ebay.
Red Dynasty NXT Shocker
Black Naughty Dogs NXT Shocker