All this is for big power, and you'll need to open the transfer port to max. For FT, if you are shooting .22, look for 610-615fps w/13.34gr, 14+gr,600-605. If using .177 for FT, up to 685fps w/7.9gr. For FT, the transfer port need not be any bigger than stock or smaller in .177.
My P-Rod has been converted to .177 with the o-ring mod. .076 id transfer port. I don't recall
the hammer and stroke adjustments. I'm getting 685fps avg for 40 shots w/20+ spread. I'm not
a tinkerer so I left it at that. It can be WAY better.
Since PFT is only 30yds max, even a 30 spread won't show up on target.
This is an excellent way to tune all Marauders. If you have a regulator installed AND the o-rings,
60+ shots are the norm with a near non-existant spread. (We have a Marauder rifle shooter in our
club who gets just that, 60+ shots with a 5 spread.)
Let me know if I can be of more help.
bstaley did all the work, I'm just passing it on. Good luck!
Head Gopher and Assistant
Match Director Ashland Air Rifle Range