Marauder recessed screws on top of scope rail ?

[discoduck]

I asked this question in another thread but it was suggested I start a new thread to prevent the question from being buried.

What is the purpose of the recessed screws in front of the magazine on the scope rail ?

I can't find and exploded parts diagram anywhere and the manual doesn't seem to cover these screws.

The other thread.

http://www.gatewaytoairguns.com/airguns/forums/thread-view.asp?tid=20317

[Rolls-Royce]

Those are the receiver's barrel retention screws.  Be advised that removing these still won't allow the barrel to come out, as there is a transfer tube between the airtube and barrel that fits into a hollow milled into the bottom of the barrel, and it will keep the barrel in place. The receiver and barrel setup have to come off together then you can pull those screws and slip the barrel out of the receiver