Tried a rammer by buying a Remington.

Found it to be about 7fpe with a slow but slamming firing cycle.

Spent some time looking for replacement rams, it seems to have a cheaply built gas ram that has too much friction in the seals, I think the nasty "slam" in the firing cycle is due to the piston landing forward after the pellet had left the barrel.

Bought a Titan spring for this (picked it from measuring length and diameters of action) and machined up a spring guide for it. This has restored the power, much nicer shot cycle and it more accurate!

Not really a good intro to gas rams, I expect a more expensive ram would work a lot better.