Plains rifle is 28" according to CVA. You wont gain much velocity from anything longer than 25". Maybe 25fps per inch depending on the load.
The Optima V2 pretty much splits the difference. Its nearly as light as a MR, about the same as the PR and has a 26" barrel for around $100 less. Plus you can get iron sights or a TH stock for it if you need.
Plenty of long range wins and great scores at Friendship's Inline Match have come from 27" barrel rifles but very few were break actions of any brand. Long range inline shooting is dominated by bolt actions and a handful of total custom Omega builds.
Last edited by Gm54-120; 01-25-2018 at 07:48 AM.