I don't have one, but how would an air cylinder work? It should be faster, and if you already have compressed air it would be cheaper. Heck, it might even be cheaper if you if you had to buy a small compressor and tank. A 4" cylinder would give you 1256 pounds of force at 100 psi. Just a thought. If this might work for you, I'll check around our warehouse at the plant and see if I can come up with one.
Steve