I have been reading as many posts as I can, not just here but Ive also been having a look around in general for information on replacing the mainspring of a standard or ordinary pattern model D. It was interesting to hear opinions about one or two springs being preferential as well as getting information about spring dimensions, length, inner & outer diameter, wire type (round v flat) wire thickness number of turns, pre load.....lots of variables without even looking at spring rate & metallurgy or conditioning the spring before use.
Certainly a lot of information to think about before deciding how to go about replacing the spring. While thinking about it I was wondering if anyone has measured the cocking effort required on one of these that is shooting well & what velocity it's giving. Smooth shooting characteristics are obviously desirable & there are some expected velocities quoted too but I've not seen any figures on cocking effort. How much effort is detrimental to these old air rifles. Any ideas?