First of all, I'm curious what the largest seat is that is capable of being fitted. I've got a 6.5mm seat in mine, and a 7mm valve seal. I got a massive power drop on my .22 (as expected) over the 5.8mm seat I had. Whether from loss of velocity, or from increased force required to open a larger valve... probably both. I did create a more streamlined shape for the new valve seal in 7mm, and using it on the 5.8 seat did net a tiny power increase.
I will be tuning my gun to shoot 30 caliber pellets as well. I have no interest in slugs of that caliber.
I will be tuning my gun to shoot 30 caliber pellets as well. I have no interest in slugs of that caliber.