Is there enough time to use a speedloader?
Most speed sports I shoot in have a 20 second/10 shot limit, I suppose you can reload, you will have fun but never compete against the 10 shot guys.
At our club we have 2 bowling pin leagues a year, each league is 10 weeks (every Friday). At the end of 10 weeks, each shooter turns in 10 timed scores and the 6 best timed scores are kept. Each score is 4 consecutive sets of 5 bowling pins (4x5=20 pins, total league score is 6x20=120 pins). A missed pin counts a default of 20 seconds, so if you miss a pin it will most likely be a score you throw out, so you don't want to get too many misses.
We have 3 divisions, semi-auto iron sight, semi-auto optic and revolver. Revolver optic has to shoot in semi-auto optic. You can shoot all 3 divisions if you want to.
The whole idea is speed, that's where a 10 shot has it's advantage, with a 6 shot you have to be careful and careful is slower.
We don't allow practicing before shooting a score on that night, but you can practice several weeks before if you want to. Also if you shoot a score and then do a practice line, you can't shoot another score until the next week.
We used to use real pins but since they are too hard to get now we are now using steel outline pins that are on a hinge, also much faster to reset, just pull the rope.
Old video:
Steel pins we use now: