*is the sweet spot for a full cylinder*
I don't know how or why people interpreted that as 455mm being the ideal barrel length, it's JUST the ideal barrel length for a full cylinder.

Also, just because a gun has a 20" outer barrel does not mean you need a 20" inner barrel. All the systema ptw M16s come with 14.5" barrels

I am leaning towards the ORGA 6.23 for my P*

There are many good reports of the ORGA 6.23 Magnus working very well on P* systems. Did you have problems with it on yours?

The problem is it the only thing it does better than the 6.13 is use more air. The performance is exactly the same

I am using a 6.05 with great results. Do you know if the 6.13 perform even better than the 6.05? I am not concerned about air consumption. With a 68ci 4500psi bottle, I get tons of shots.

Depends how many rounds you go through in a game and how frequently you clean your barrel

Not a heavy shooter. But I do clean my barrel after each game.

Just stick with the 6.05 then