I remember these "Ranger" guns having a rubberized tank, but never knew how large the metal tank tube was underneath the outer covering. I had some reservations about how long that rubber cover would last, so I did not buy one when they first appeared here. Maybe you could measure the actual tank tube diameter while you have the gun disassembled and let us know what the size is. From the exploded diagram it appears that the "Ranger" guns follow the construction method whereby the rear handle housing is a separate moulding that slides over the actual pressure containment vessel, itself being another plastic moulding. The Technisub "Grinta" and "Jeans" guns were of a similar, but simpler construction, being earlier models with slim air tanks of 30 mm OD. The hand grip on these two slim air tank guns was integral with the rear handle moulding, unlike the "Ranger" which has a separate yellow grip that appears to attach with a screw to a skeleton frame projecting downwards from the rear handle housing.
I am trying to figure out how the power regulator works from the exploded parts diagram, it is a different system to the Mares "Sten" type guns, but from reading the operating instructions appears to have the same "easy loading" operation, i.e. you can pump the spear to progressively charge the gun for the next shot. The "Grinta VP" model uses a throttle system to adjust shooting power, so it is not an "easy loading" feature. I note the "Ranger" diagram indicates a "VP" version, so that is something else to figure out.
