I have ordered a Ruger American 22 Mag with the 18" barrel. They offer a 22" and I believe in longer tubes if they give me something, like in my 264, 25-06 & others but I don't think it is the case in 22Mag. I have told a friend this but my personal research is lacking as this will be my fist 18". So I don't want to mislead anyone, I want data from those that have done a direct comparison.
I got this comparison fron Rimfire central, but the Marlin has different rifling if that matters:
Ruger American--Final Chapter - RimfireCentral.com Forums
I also have seen a test result on 17HMR here:
Bullberry Barrel Works - 17 HMR "Match" Velocities
Has anyone tested this, thanks