1.69% extreme spread across 90 shots

Thank you Michael! I believe that Extreme Spread percentage is essentially just the ES (15) divided by the shot count (90). I never really looked at the string that way until I started using Triggertreat's shot string calculator. It also helps you see which shots may fall within a certain spread. I just have a harder time wrapping my mind around the standard deviation number...

Sorry the whole string would be too small to be readable here, but here is part of it

Oh, I should also mention the Bigmax, like most Kral guns, is not regulated. But it does have two air tanks for a combined capacity of 850cc.

Ha, no worries. ;-) 

The Bigmax groups I posted we're with jsb 18s straight from the tin. Tell me about your gun. It must be cranked up a bit to shoot the 28 grain pellets. Are the jsb mark II you mentioned the same ad the monsters? I'm not familiar with that pellets. I have tried the redesigned monsters and had really mixed results.

I has some great groups at 33 yards, but terrible groups at 63 yards.

Wow, that's a lot of power for a .22. Did you have to open up the transfer ports to get it there?

The cheek weld is OK, actually better than I was expecting. And the plastic cover on the bottle is fine - even shooting in New York winter temperatures. I do wish the butt was a bit taller or the butt height was carried a bit more forward for shooting off a bench though. This is what it looks like with a small rear bag:









Negatives regarding the gun? Yes, when tuning, I do have to dump air out of both bottles so my shoebox is getting a workout! I'd like to find a way to cap off the block's port for the rear bottle to save air when tuning but I've not found the right method for this yet. Speaking of tuning, the hammer spring adjustment is VERY limited. It came almost fully backed out. I also found that I can't turn it in very far (maybe a turn and a half) before the gun won't cock. The trigger is decent. I'd say it is a little more vague than the Quatro trigger on my Hatsan Flash. The gun definitely needs a ldc to be backyard friendly.

Here's an earlier series of groups, 9 consecutive 10-shot groups at 53 yards with JSB 18s:





Wrapping this up, I would give the gun a thumbs-up. Especially given the deal from PA I got... It was their "pre-blackfriday" sale and they were offering the gun for $500 but at that time their usual extra 10% was being allowed, so I got it for $450 and that still included the "free" extra magazine and mantis scope and rings

Very interesting @paulb. It's cool to get updates directly from Turkey

Just quick update... without any mods to the rifle, my last shot string increased from 90 to 120 shots. The difference? I topped off the rifle a few times while out in the cold. I filled to 210 bar, shot a bit (8-10 shots while fiddling with chrony) and cycled through this a few times. So I suspect trying to do one big fill actually results in significantly less air in this two-tank gun. Even though I don't feel the tanks warming during the fill, there likely is quite a bit of pressure loss when trying to fill in one shot.