I know that it is bad for a springer to be cocked for long periods of time, eg. when rat hunting where you only take a shot every 20min to half an hour.
I want to know if it is bad for a PCP to be cocked for so long too?
do you perhaps have an old spring laying around. You could do an experiment for us
put it in. Chrony rifle. cock and leave for 24hours. chrony, cock leave.. etc.. I am sure it will affect it. How much is to find out. Keeping a spring compressed must surely set it to a certain degree right?
The 'leaving a spring gun cocked for extended periods being bad for it' is an old tale that at one time may have had some truth in it but with any modern good quality spring it makes absolutely no difference.
By way of example I recently fitted a brand new spring to an HW80 in .177. The first few shots came out at 860fps then it settled down to 825 fps - a bit too fast. I thought I would cock the rifle and leave it stand to try and 'set' the spring to lower the power - 7 days later, loaded a pellet and fired it over the chrono - 823fps for first shot then back to 825fps average after that. In the end shortening and refinishing the spring was the only way to get the power down.
Back around 1994 I also inadvertantly left my SM100 cocked for a week and no power drop ensued from that.
If your rifle does lose power after being cocked for an extended period then the spring was shagged anyway and should be replaced with a decent quality spring.
If a spring is properly designed and the metallurgy is right it will not fail if left cocked on condition that it is not stressed beyond its design capabilities.It will also not weaken.
The only failure or weakening that will occur is through continual use (cyclic loading). Under these circumstances a component can only last a certain amount of cycles and it will progressively deteriorate from the first cycle. The weakening or failure eventually is commonly referred to as a product of FATIGUE.
Because spring guns recoil they are harder to shoot (although if you master a springer it will help you be even better with a pcp). A pcp is more forgiving if used from all manner of odd positions in the field.
Also if you have need for higher power springers become more limited in what they can achieve - a reasonable maximum being mid 20's ft.lbs from the likes of the HW80 and Pro-Elite - OK the Theoben Eliminator will go over 30ft.lbs, but you try cocking one several times
PCP's will go to higher power for less hassle.
Mike, with quality springs that deterioration takes an awful long time. What does wreck them as well is the shock loads imparted with violent dieselling.