Thought i would share a VERY NICE retrofit that I've never read about and works great !
Long story short ... Air gun show a few months ago found this small .2L ( 200cc ) bottle that when asking about it, came off a BSA R10.
Figured for the $10 seller wanted i could find a use for it eventually. So happened that when doing some in depth R&R with the 400cc bottle on my TM-1000 ( Bottle version like an HM ) well son of a gun if it did not SCREW RIGHT ON and sealed up & opened the check valve too !!
So here it sits on my .20 cal TM-1000 and it provides plenty of air for a full round of Field target. In use it actually provides @ 90 shots at > 20 ft lbs. ( modified gun mind you )
Real PLUS was the clearance it opened up allowing a FULL LENGTH shroud of which in now fitted. 1 1/4" O.D. BTW making the gun stupid quiet. While the clearance between bottle / shroud is tight, both are so stiff and flex free they don't come together even holding the rifle by the bottle shooting. COOL
Less weight out front has aided off hand steadiness too. A True win win and great mod for those application where you don't need a big heavy tank & big volume.