JTS Airacuda Barrel Cleaning Help

[jusanothajoe]

Received my Airacuda Standard .22 yesterday and was able to shoot a few mags before rain ran me inside.
Accuracy was great yesterday, well today accuracy went south immediately, knew I probably didn't clean the barrel real good as I was trying to beat the rain, so I cleaned the barrel again and first patch came out BLACK.
Took 15-20 patches to get clean and accuracy returned just as fast as it left.
Long story short, I get 3-4 mags, then accuracy leaves and barrel needs cleaning again and first patch is filthy black.
This went on 4-5 times this afternoon.
Anyone have any suggestions ? I'm filling with a JTS compressor, have filled my Standard .25 with the same compressor
25-30 times and never had this problem with it.
Any help is appreciated.

 

[rdtricks]

From your description, it reads as if you have a rough barrel. Nice to know the accuracy is there. You might want to take a little time and 'bore polish' this barrel with some J&B Bore Bright or another metal polishing compound of your choice.

 

[Struckat]

Not a pcp, but my HW 30 needed its barrel cleaned every 1,500 shot or so. Then I used JB Bore polish and I can go 3-4000? Not sure as I have not had to clean it since.

Just my experience with one acting as you describe.

 

[Rawroots]

Found out my barrels that need cleaning most often are on the top end bore diameter and the cure was use larger head dia. pellets, seems the smaller pellets are not grabbed by the riffling and are being shaved leaving lots of deposits. Hope it helps yours.

 

[Firewalker]

It needs to be lapped, polishing is great for a regular bore but fouling that quick means there is something grabbing lead.

Burrs, imperfections, chatter etc will need to be lapped out then the barrel needs polishing to keep leading to a minimum.

 

[Gerry52]

It takes a while with some guns & choice of ammo to get barrel "leaded" in. Have you tried different pellets to see if there's another one that will give you accuracy WITHOUT excessive lead residue?

 

[jusanothajoe]

Took the barrel off today, no visual problems in the bore, pushed several pellets through and no tight spots except for choke.

 

[jusanothajoe]

So I figured out a couple of things.
I polished the barrel and I believe it helped but.......... I found out if I fill the gun above 2700-2800 it shoots crappy, especially with a pellet that isn't its favorite, they will shoot high, low, left, right, all over.
With JTS 18's that seem to be it's favorite, if I fill to 3000 it will shoot left and not group well, as I keep shooting the groups will move right until around 2700 and then shoot to aim point in tiny groups.
I havent chrony'd it yet, will do that tomorrow.
My two other non reg guns (one is a JTS standard .25) don't do anything like this so I don't know what to do ?
Gun is just like it came out of the box, any advice would be appreciated.

 

[jusanothajoe]

Anyone ?

 

[Motorhead]

JNJ PMed me with this inquire .. my respone tho a private PM .. contained information VERY useful as a general FYI .. I stated this


Wandering POA with pressure in tank changes generally can be chased down to a specific cause & a few associated reasons for.

AIR TUBE flex within the stock and with a barrel band at muzzle, tank moves, barrel moves !!
Air tubes multipart assembly not being well supported within the stock channel is the first place to look.
* Early guns had a known issue here with wood removed in a channel forward of trigger group. JTS / Travis was providing a 3D printed spacer / support block for this purpose.

Next, remove fill cap, remove barrel band ... DOES THE BARREL TOUCH the lower air tube ? .... OR, is there an equal gap from receiver to end of air tube having zero contact any place down barrels length ?
* While doing the above, loosen & tighten Stock retention screw while watching the above mentioned barrel to air tube gap .. DOES IT CHANGE ?

 

[jusanothajoe]

Removed the barrel band and not a lot of difference, might shoot a little tighter after fill, but not much, still shooting left after fill and creeping right as pressure goes down, 2600 seems to be when it starts shooting like it should. Barrel not touching tube any where. distance between pretty consistent all the way down.
Forgot to loosen stock bolt, but I did chrony it and it looked bad in my opinion.
50 shot string started at 3200 ended at 2200
First shot 761 last 907
Graph would look like stock market, 50 fps swings shot to shot.
From reading might need hammer spring adjusted ?

 

[Dairyboy]

Well here is what I found on my Standard when it came to power wise. Something seems off with yours. Mine is very consistent over chrono. Mine is a prototype

Power levels that I saw at 2800psi went as follows.

5 detents so going to call 5 the MAX setting and 1 is MIN. Done with 16gr JSBs

5: 1030fps
4: 980fps
3: 805fps
2: 510fps
1: 410fps

 

[Dairyboy]

Also they are a 3000psi fill so you are over filling. Just be aware of that.

 

[jusanothajoe]

Thanks to everyone !
lots of shooting today and got this gun really close to being figured out.
Shot a lot of pellets adjusting the hammer spring and had to get it just right.
I was also hard headed about wanting to stay on the high power setting and this gun just doesn't like it.
Put it on setting 4 and finally got a nice 35 shot curve shooting 18gr pellets 925-895 fps.
I also cannot fill the gun but to 2800, anything above and it's squirrely till it gets back to 2800.

Motorhead gave me some advice and all he suggested helped, took barrel band off, no wandering POI, played with stock bolt tension and it helped, wound up putting barrel band back on and just barely snugged up, no wandering POI.
Ran out of JTS 18's, but got some on the way and will shoot more next week.