In exactly the same way as any other airgun. The occasional discharge without a pellet is not going to harm it.
For details of the method, see ISSF Rules 8.4.2
Rutty
Just a bit of curiosity this, how are the trigger weights checked at matches on spring powered guns?
Without a pellet to provide resistance, will it damage the piston?
Too many guns, or not enough time?
In exactly the same way as any other airgun. The occasional discharge without a pellet is not going to harm it.
For details of the method, see ISSF Rules 8.4.2
Rutty
FWB 65 etc and Diana (Original) Mod 6 and 10 spring pistols are OK to "fire" with no pellet as they have a buffer in the case of the FWB design and with the Diana design the rear piston has a damper system to limit piston speed if no pellet is loaded. While it is safe to do this I personally don't do it repetitively, but in testing for a match they will only test once and either pass or fail your pistol. Obviously if you and the equipment control guys have time you may adjust and present for a re-test (certainly the matches I have attended allow this).
BSA Super10 addict, other BSA's inc GoldstarSE, Original (Diana) Mod75's, Diana Mod5, HW80's, SAM 11K... All sorted!
When I used to shoot my FWB65 in matches, I just had to "bite the bullet" and let them dry-fire it with the testing weight hanging off the trigger. As a low powered gun that FWB used to claim could fire 6 million shots before major servicing, I assumed it would not come to much harm. But I still winced when it went off and will always wince when a springer is dry-fired.
That's good to hear, particularly as I have just got my 'new' 65 working. Even with the sporter grip and after just a couple of hours, I am beginning to wonder whether to sell my PCP and use the 65 for matches, hence the trigger pull question.
Too many guns, or not enough time?
Probably not relevant as they aren't really in use anymore. But I would NEVER let anyone dry fire my recoiless Diana 65/66/75 etc. Dry fire = expensive bill!
Spring powered or not. I wouldn't like to even dry fire my Rapids.