.25 Condor accuracy loss

I have a 2014 .25 R&L airforce condor with a 24″ barrel and the extreme valve. I’ve only shot it on and off over the years and recently started shooting again. At first I was shooting 1800# with the pw maxed out and getting 965fps with JSB 33.95g pellets.

I was getting .75″ fairly consistent groups at 50yds. Now the groups have opened up to 4″ and the fps has dropped to 945fps.

The scope is tight, the barrel is clean, all the screws are tight I keep the hold light and am careful with the trigger pull.

Is there something that usually needs attention after so many years that may have caused the loss of accuracy(my guess would be I’ve shot around 1000 rounds).

Thanks,
Rick