Kral Arms Kral Puncher Breaker Seal with misc...

[mprescott]

Hello,
I am new to the forums and fixing airguns however I was hoping others could help me with my gun's possible issue. I have a Kral Puncher Breaker that was shooting okay until I did patch cleaning to the barrel to see if I could get a better grouping, it seemed to work for half a tin of pellets but then I noticed near the breach of the gun lots of moisture was coming out of the barrel. At the same time, my groupings are really bad, some shots are pellet on pellet at 50 yards, and then the gun randomly shoots 3 inches away from zero with another group. This gun is also weird since every time I fill it with my scuba tank to 180 bar, it will shoot in random groupings as far as 6 inches away from zero. I have taken off the shroud to see if the pellet is clipping but nothing is working.

I do have an air venturi gun that is damn accurate with no problems and I have tried different scopes too, but nothing seems to be working for this Kral.

Thank you for your time,
-Matt.

 

[aroundlocks]

Hi Matt
you need to put gun over chronograph and see if its shooting consistently" first.
if fps are ok then remove 2 grub screws and remove barrel and push a pellet through and check for marks other than the rifling.
If all ok with barrel and crown / fire some cheap pellets through to re lead your barrel and see if it improves.
You dont say how old this gun is or what projectile your shooting.
The moisture is not right and should not be happening.
You may need to remove air tube and clean it inside to remove any moisture from it.
It is also held in by 2 grub screws.
Make sure no air at all is in the tube and completely Empty""""before removing the valve housing end of the tube.
Take heed then ends are SUPER TIGHT and will need clamping in a vice with 2 wooden half moon blocks.
Why valve is out replace poppet spring to a lighter type too remove the nasty twang krals seem to suffer from.
Refit the tube including new Oring on valve threaded end .
After that adjust hammer spring to set the fps as it would have gone up slightly.
find the source of moisture entering your gun " use an inline filter to remove water..
Let us know how you get on

 

[mprescott]

Awesome thank you so much. I have a Kral Puncher Breaker .22 cal roughly 4 years old since I bought it. I have been shooting JSB 15.39g and Crossman 14.3g, which were shooting okay until recently. I ran 20 pellets through a chronograph last week and found the STD is 7-9 fps per shot, the best group seems to be 11-16 with a STD of 2.44 fps from starting at 200 bar on the gun.

Shot #	1​	2​
1​	795​	806​
2​	806​	800​
3​	811​	803​
4​	803​	801​
5​	797​	799​
6​	803​	793​
7​	798​	808​
8​	804​	806​
9​	815​	807​
10​	810​	823​
11​	815​	804​
12​	817​	810​
13​	814​	805​
14​	814​	811​
15​	811​	808​
16​	813​	806​
17​	810​	803​
18​	803​	793​
19​	796​	780​
20​	798​	787​

I will open the gun up, I contacted the scuba shop which is where I get the air from and they practically have no moisture problems as their tests show. My tank was inspected a year ago with no moisture pitting, so I'm really baffled if there is moisture in my gun. I do however believe I have a leaking seal from the barrel that is expelling the high-pressure air which causes it to condense since the gun breach is cold to the touch. Thankfully the tank does not leak any air from the gun sitting around.

I saw a video from Annihilator Airguns on YouTube on how to take the gun apart. The poppet spring sounds like a good idea and I'm not looking forward to unscrewing the difficult thread locker which is on everything with this gun.

 

[aroundlocks]

Hi mat
Not thread lock
When they screw the ends into the tube the orings get chewed that's the problem.
They will come out but are extremely tight" remove gauge and use hot air to warm tube where it joins.
The gun itself is easy to strip down to component parts other than the tube.
2 orings on the barrel breech end and should be one oring inside barrel where probe enters.
Airtube has 2 orings valve end where it goes into the block/ just replace all orings you come across.
Two of my krals both had that twang" it's not hammer but poppet valve spring.
Your gun looks very consistent fps wise being unregulated " so it's not that causing the problem.
Drop your barrel out and check the crown end of the barrel for damage and the leade in end and oring for damage also.
Push a pellet through I use a pointed rod similar to the probe end" that way the rod does not touch the skirt and look for Nick's or Mark's with s magnifying glass
Check the probe seats central to barrel when your closing the cocking lever.
After you do all that Matt lol and your happy with barrel put back together minus shroud and use single shot tray not the magazine" and shoot a couple of groups and check accuracy again.
The magazine may be the cause also.
Make sure barrel grub screws go back into the detents and are tightened up" so no barrel movement .
Remember to empty gun of air first before taking it apart.
Keep us informed on how your getting on

 

[mprescott]

Do you know how to take the barrel off, I took the two grub screws out on the top of the gun and the barrel is stuck on. I have the entire tank off too, and used vise grips with duck tape and rubber to try and turn the barrel without scratching it but it's not budging. Is it safe to use penetrating oil? I put a couple of drops of Ballistol down the screw holes and between the barrel opening (where the o-rings are holding the barrel), but the darn thing is stuck on. I'm following a couple of YouTube videos and both show relative ease in taking it off.

I appreciate your help,
-Matt.

 

[aroundlocks]

Hi mr Prescott
There should only be the 2 grub screws holding it in with 2 orings inside the breech block and it should slide out
If no more screws inside the 2 holes it should come out.
Maybe o rings are damaged holding it in
Here is a pic of barrel end

 

[mprescott]

That's what I thought, but the darn thing does not come off. Do you have any ideas on how I should remove it, I really don't want to use a pipe wrench and gouge the barrel all up, but at this point, it's stuck on there for good.

Thanks,
-Matt.

 

[aroundlocks]

Hi you could find a 1/2 inch unf nut or screw a silencer on to give you more grip to try and turn it.
Or if that doesn't work drill a 11mm hole in a block of wood cut in half and clamp into a vice with barrel sandwiched in between and try turn breech block.
It shouldn't take excessive force to remove it

 

[mprescott]

I was finally able to get it off. I first heated the receiver block barrel section with an electric heat gun, then placed the receiver block upside down in a vise while pulling the barrel straight out while wacking the receiver block's air tank holder with a plastic mallet. It took 1h of excessive force (hammering/heating) to remove it, thankfully nothing got damaged. It's really weird why this darn this was on so tight, there's no glue I'll have to measure the tolerances. The O-rings are in good shape, except where the transfer port and screws were as it nicked off some rubber so I'll have to replace those.

Thank you for all your help aroundlocks

-Matt.

 

[aroundlocks]

Hi mr Prescott
Glad you got it removed.
Maybe now removed it should just be a slight interference fit that's all.
Remove o rings and see how it slides back in without them installed.
Glad to help you anytime.
Take care