I also took out the airflow restrictor on my front gun, but I did not use a Dremel (mainly because I don't have one and don't like to drill into my guns *lol*).
It appears that the 'endcap' (with the black rubber ring around it) is only glued to the plunger tube in one spot; the rest of the area can be opened. I was able to carefully pry it off with a flathead screwdriver (although the plastic did not seem to like my screwdriver). The 'glued part' took a small part of the surrounding plastic with it, but by adding a drop of superglue I managed to glue the endcap back on (don't know if superglue is the correct word, as in our country it's called 'seconds-glue').
So if there's anyone (like me) out there without a Dremel, but with access to a drop of superglue, this might help; I think
1x N-Strike Unity Power System (Scout IX-3, Hornet AS-6, Titan AS-V1)
4x Maverick Rev-6 (one has been modded)
1x Rapid Fire 20
1x Scout IX-3
1x Air Blasters Shotgun
1x Star Wars Jango Fett Blasters (2 blasters in the set)
1x Star Wars Rebel Alliance Bowcaster (Disney Park exclusive)
1x Star Wars Boba Fett Wrist Gun (battery powered and fires round foam discs)
1x Longshot CS-6 (front gun has been modded; now seems to have double the power)
Whilst oogling the collections of other users, I couldn't help but feel in awe about the sheer looks and ferocity of the Razorbeast.
If I wanted to add to my collection, that one would surely be at the top of my wishlist. But I guess those things have become really rare...