I don't own a shadow anymore,...but have some info on what top shooters use.
JP Ithink now is using a 147gr bullet, although to win the 2009 Nationals I think he used 124gr bullets. Cliff Meek used a 147gr bullet,...
Not sure what Nick King uses..?
Matt Mink uses a 124gr,..while I think Angus uses a 124gr as well?
Adam Tyc is sponsored by an AMMO company in CZ, which makes 124gr ammo.
Factory ammo is always going to have higher velocities. I prefer 147gr factory ammo over 124gr factory ammo,..although the147gr winchester will have a slightly higher PF,..it still feels better in my stock2 tanfoglio. I use some 147gr factory for practice, and use 147gr Canadian BDX ammo to finish off my practice and use in matches. (factory is about 144pf, while BDX is about 136 pf)