Kral Information Thread. “Contribute what you know “

Factory 15-3/4" barrel at 3100psi ported with a smaller diameter poppetvand debounce hammer spring does 24 shots at 900fps with 18.13jsb on the NP03 with no reg needed at well under 20fps ES.
The gun in question is the 25 cal 10-3/4" np01 barreled mega I built. I dropped it back to 3000 psi fill getting 735 fps for 24 shots in the peak and a few before and after so it's a 3 mag gun. It's super smooth to cock and alot quieter now.
 
I make "Right Side" magazines for the Kral Puncher, Mega, Pro, & Breaker series of rifles. I had bought a Kral Mega Marine and a FFP scope with a parallax wheel. The stock magazine interfered with the wheel. I was going to put it in the classifieds but I don't have permission to post there yet. If you PM me I will send a link to the eBay listing and you can check it out for yourself.

Rich
 
refurb is ready for work !!!

NP-03 equipped.jpg
 
I Converted my Kral Bighorn to a 4000 + psi fill gun today. I was about to buy a 4500 psi bottle to replace the TalonTunes 3625 psi bottle, then I remembered I had a 4500 psi bottle on my Texan LSS 257. My son has had that 257 for over two years, so I had him drop it off along with the 60 minute tank, and to do the swap and refill I really needed that 60 minute tank.

So far on the Bighorn it has been ported and valved by Troy, he also did his mod to the hammer and I received it from him with a Benjamin Bulldog spring. To open that valve at higher psi, I replaced the Bulldog hammer spring with a heavier Pitbull hammer spring, the Bulldog really needs a steel side lever to use it, I have one on my Bulldog carbine.

I had experimented with higher pressures with the Talontunes tank, 4000 psi and feel safer with the 4500 psi tank, although 375 more psi is not going to hurt that Talontunes tank, it is that I plan on going to a higher thann4000 psi and increasing until the valve tells me I have reached hammer spring/psi level, at which time I believe I should see a start to a bathtub curve shot string.

At somewhere around 4500 psi the pressure disk should fail, something I want to avoid, hoping to see 4200-4300 psi operating level.

Regards,

Roachcreek
 
well, the working refurb has a leak !!!
it leaks down over 2 days to about 100bar from 200bar fill.
any ideas before i tare into it ??
i've got my grandson to bring me some balloons to put over the
muzzle and 1 for over the fill port of the tube.
i installed the huma regulator last weekend and nothing more.
hopefully its an easy fix.
 
well, the working refurb has a leak !!!
it leaks down over 2 days to about 100bar from 200bar fill.
any ideas before i tare into it ??
i've got my grandson to bring me some balloons to put over the
muzzle and 1 for over the fill port of the tube.
i installed the huma regulator last weekend and nothing more.
hopefully its an easy fix.
I've never had one leak. Try some silicone oil in the fill probe and pump it in with your air source. Might just need some oil on the check valve or valve seal.
If the regulator seals aren't lubed good it can cause a slow leak around the plenum/reg seal.
 
With a 4200psi fill, in a 4500 psi cf tank, using a 44.5 grain MPMolds hp I hit 946 fps with my 18 inch barrel.

Pleased with my 25 Bighorn,

Roachcreek
That's cookin!! I wonder how much difference there is between the BH and jumbo bottles. I know the drop block and valve are much bigger, action is longer for hammer I guess. I'm about maxed at 50 fpe in my 16 inch barreled 25 jumbo. I could get a bit more spring behind it but it's a smooth lock up and cocking so I don't wanna mess with it. It's also super accurate with 25.4s and the Cuda 31 grains. Slugs it's so so with 33.5 NSAs. The chokes hinder slug performance on these rigs.
 
With a 4200psi fill, in a 4500 psi cf tank, using a 44.5 grain MPMolds hp I hit 946 fps with my 18 inch barrel.

Pleased with my 25 Bighorn,

Roachcreek
Very nice. I am thinking about eventually building a dedicated slug gun. Good to know a Kral platform can do it. How is the accuracy with your barrel?

My latest experiment has been with the hammer spring in my Puncher. I had a little bit of preload with a 10.4 lb/in spring to hit 875 fps with 15.89s and thought I can decrease bounce by using the 12.5 lb/in spring. It is now hitting 900 fps and being fine tuned.
 
I did a lot of work on my barrel which is descrbed in this thread. Mainly cutting off the choke and polishing to give a very slight taper from breech to muzzle. Someday I need to get a longer barrel, perhaps a unchoked TJ from Troy.

The Bighorn is A NICE platform once ported and properly sprung.

The furtherest I have shot it is around 35 yards, nickel sized groups with a wobbly bipod and a nearly blind shooter, which is my limit these days.

Regards,

Roachcreek
 
I really don’t have experience with any other Kral platforms with the exception of the Benjamin kratos.

I ported the Kratos to .20 and added a 3625 psi bottle to it. I was able to achieve 62 FPE with Kings. Hardest part of the porting was enlarging the passage way through the power adjuster. Before attempting that chore I ordered a couple spares from Crosman. One I opened too far, the 2nd one I took my time using a small round Swiss file, the third power adjuster is a spare.

I also removed the Valve return spring on both the Bighorn and Kratos, on unregulated guns that will give you a 35-40 fps gain.

Regards,

Roachcreek
 
That moderator on there is NOT going to be air tight, take it off and run the test again
Yep, I was thinking that too. Should also pull the shroud off and put the balloon directly on the barrel.

@gendoc, it's most likely the plenum o-ring that's what mine did the first time I installed it. I replaced the little o-ring that's on the bottom of the reg where the plenum locks over.