Katran x hp comes with CZ 700mm unchoked barrel. Really meant for slugs. The gun is a powerhouse from factory, really meant to shoot heavy .22 slugs like 25 to 35 grain. Was shooting 1050 fps with 25grn and could still be turned up more. With stock configuration reducing the hammer spring tension on stock reg pressure will cause high spreads and shot to shot deviations. It likes within a couple turn from max and any more the spreads get erratic. The hammer spring adjustment is somewhat sensitive..1/8" to 1/4" turns at a time. Little increments go a long way.
For my purpose and goal for this gun build. I wanted to detune it for lighter slugs and maximize shot count with its 300cc air cylinder. This is my yard gun and want setup to be mid 900 fps with light slugs and get the most shots per fill.
To accomplish this I put a 4.9mm transfer port sleeve and transfer port restriction adjustment screw. I turned hammer spring 1 full turn from max. Shot some string adjusted transfer port restriction. I then backed the hammer spring to just before spreads increase. The tone of the gun changed to a quieter subtle pop as it became more dialed. Hearing that reassured I was reducing excess wasted air and fps wasnt dropping.
Note, the regulator is very good similar performance to Huma regulator. No reg creep or weird flaws. Trigger is now adjusted and awesome, nice 2nd stage wall clean break and no overtravel. I dont have a gauge to measure. Guesstimate would be under 8 oz. Very light.
Final result after some tuning and testing between .218, .217 and .216 slugs. I nailed this build and could not be happier with the Katran x hp. Now shot strings are 938-940 with couple fps spread, very tight and consistent. 300 bar to 150 bar for 4 mags totaling 64 shot for 2.5 bar per shot at 34.5 fpe. Likes .217 sized slugs the best.
Best 100 yard 5 shot groups of this morning, rested on a sweater over the roof of my car. The Katran loves .217 NSA 17.5grn at 938fps and Jsb knockout .217 25.39grn at same power settings 815 fps. My thumb measures 1".
Overall I am very pleased with the Katran and could not be happier. Lightweight, ar grip compatible, hand pump friendly, accurate with slugs, powerful if desired, good shot count, folding stock, build quality and price point. Next plan will be to make custom oversized shroud to take up the room between the air tube.
For my purpose and goal for this gun build. I wanted to detune it for lighter slugs and maximize shot count with its 300cc air cylinder. This is my yard gun and want setup to be mid 900 fps with light slugs and get the most shots per fill.
To accomplish this I put a 4.9mm transfer port sleeve and transfer port restriction adjustment screw. I turned hammer spring 1 full turn from max. Shot some string adjusted transfer port restriction. I then backed the hammer spring to just before spreads increase. The tone of the gun changed to a quieter subtle pop as it became more dialed. Hearing that reassured I was reducing excess wasted air and fps wasnt dropping.
Note, the regulator is very good similar performance to Huma regulator. No reg creep or weird flaws. Trigger is now adjusted and awesome, nice 2nd stage wall clean break and no overtravel. I dont have a gauge to measure. Guesstimate would be under 8 oz. Very light.
Final result after some tuning and testing between .218, .217 and .216 slugs. I nailed this build and could not be happier with the Katran x hp. Now shot strings are 938-940 with couple fps spread, very tight and consistent. 300 bar to 150 bar for 4 mags totaling 64 shot for 2.5 bar per shot at 34.5 fpe. Likes .217 sized slugs the best.
Best 100 yard 5 shot groups of this morning, rested on a sweater over the roof of my car. The Katran loves .217 NSA 17.5grn at 938fps and Jsb knockout .217 25.39grn at same power settings 815 fps. My thumb measures 1".
Overall I am very pleased with the Katran and could not be happier. Lightweight, ar grip compatible, hand pump friendly, accurate with slugs, powerful if desired, good shot count, folding stock, build quality and price point. Next plan will be to make custom oversized shroud to take up the room between the air tube.
