Which ms361 Barrel

[Kebo57]

I’m making one ms361 from two ms361’s. I have two good barrels see pic


They have different porting
Left one is a see pic below

Right one is a see pic below

Left one seems to have more crome they are within a couple of thow in diameter.
Which would be the best one to use and why

 

[snobdds]

I like open port a little better for power, but closed ports get better longevity.