Theoben 700mm barrel and 700cc buddy bottle on a theoben mk2

Wondering if someone put an 700cc buddy bottle and a 700 mm barrel on a theoben Mk2, and what where the results of this modification?
I have a couple of barrels that I would like to place on the rapid mk2, 700 mm .30, 650mm .25 and a 650mm .177 all from Alfa Precision.
Also want to put an 700 cc bottle on de mk2 for more shots, should be a simple replacement.