Texan Carbine Finally Arrived 357

Sighted in at 50yards.

145 Noslers
Shot real well.
Shot 1: 3000psi
Shot 2 : 2800psi
Shot 3 : 2600psi
Is that about normal?
I did not use a chrony…its on order.

But at the same hundred yards aiming above the bullseye I couldn’t even hit the target but hit the 2×4 ( complete pass through) below the target about 10 inches below the point of aim.
Can you tell me what is going on?
I also noticed that the bottle was loose….firmly attached just a lot of movement…could this have anything to do with the inaccuracy? 
Would adjusting the power wheel up or down help? I have a hard time believing that the round dropped by 10″ at 100yards.

This target was at the 50yards

Once I came home I tightened all the screws, bolts and the tank. Is the gun capable of a 100 plus yards? There is not a lot of information on the Carbine.