My two blasters, Both ACM M500's.
Internal work done to re-seal everything correctly
The top one has a custom rail bolted on, as well as a Guarder Aimpoint and NC Star Light/Mount. It's also sporting a real steel ATI Mossberg stock.
The bottom one was cut down by myself, as well as re-did the loading mech to work in the MUCH shorter loading tube. Pretty sweet, if you ask me.