I have a selection of 'lighter pellets including JSB 13.73 gr waiting to a test a project Meteor so I'll bring the Kral to that party.
Last night I dug out a Titan #13 meant for my paratrooper but was too tight on the spring guide. It fits the kral sleeved piston a miniscule bit looser but Lyndons spring lube will cure that and is a tight fit on the guide but not so tight that you cannot wind it on like an acetal version.
I'm definitely going to fit the OE spring first and if it does not improve then it will be fun & games with the Titan.
Yes it is very Gamo esque just some parts better made.