I replaced the Oem barrel on my Kral Bighorn it was a 18 inch dechoked barrel. My TJ is 28 inches. The kral’s 18 inch barrel was shooting 44.5 grain bullets at a one shot high of 940 fps, but ranged down around 910-920 fps.
The Kral Bighorn has Troys tune .24 tp and the hammer altered to use Bulldog springs and the valve return spring removed. I am using a heavier Pitbull spring and the 3625 psi tank has been replaced with a 4500 psi .5L cf tank.
After the barrel change the first string was after turning the hammer spring out two turns, 1021,1049, 1030, 1035,1023,997,997,943,917. Starting pressure from a .5l 4500 psi tank was 4200 psi, ending pressure is 3300 psi. The first 7 shots are not too bad, but it drops off fast. 9 shots averaged 1001 fp/99 foe.
The second string was shot after two more turns out on the hammer spring.
929,997,989,981,987,987,980,1009,998,975. Starting pressure 4200 psi ending pressure 3500 psi. This string shows a bathtub string clearly. Average velocity 983//95.5 fpe.
I had planned on returning the VRs, but not so sure now. I might try turning the hammer spring back in for the next string.
Regards,
Roachcreek