Wildcat Question For You Owners

Forums PCP Airguns Wildcat Question For You Owners

  • Views : 519
  • Link

    jking
    Participant
    Member

    I'm working through an issue with the POI changing on my 25 WC. I can have it dialed in and shooting one ragged hole groups out to 60yds. Put it up for the day, take it back out and it might shoot a 1 1/2 high and an inch to the left the next day. I pulled the Hawke SW off and replaced it with my SWFA 12X and I thought that took care of it but it drifted off of zero again today. The velocities have been very steady, shooting MK1's around 875. I think this started after I had the barrel and shroud off. Today I noticed that the shroud bushing closest to the breech or air tube clamps was up all the way against the air tube clamps. I never loosened this bushing on the barrel and I double checked the set screw impressions by looking down on top of the receiver into the hole where the set screw secures the barrel. It looked perfectly aligned. Just wondering if changing temps might induce POI change with the bushing snug against the air tube clamp.

    My thinking is that possibly the bushing being up against the air tube clamps might some how be tensioning the barrel and interfering with it's free floating. I slightly adjusted the barrel outward so that a .015 feeler gauge would slide in behind it. So my question is are you guys seeing a slight gap between the bushing and the air tube clamp? I haven't re-zero'd yet to see if that makes a difference so the jury is still out.

    Another question on the shroud. On my gun the shroud screws onto the rear bushing and then on the muzzle end the air stripper with a shoulder on it screws onto the end of the barrel. I do know that the air stripper never bottoms out on the 1/2 X 20 barrel threads but stops turning and tightening when the shroud mates up to the shoulder on the air stripper. Makes me wonder if it's designed this way which is actually tensioning the majority of the barrel. If the shroud was a tad shorter the air stripper would tighten down on the barrel first and not hold that tension on the barrel.

    Hopefully getting the bushing away from the air tube clamp MIGHT help. I would appreciate it if someone would check there bushing to clamp gap if any. Preferably on a unmolested gun.

    Jimmy

    Link

    RM100GUY
    Participant
    Member

    jking, I just looked at my  WC Mk1 .25, there is appx. .050" to .060" between the shroud bushing and the front of the front clamp, I don"t think moving the barrel out is going to help, sounds like the location of the AS & shroud, never had mine apart, my 2cents worth, good luck.

    Link

    Rj
    Participant
    Member

    Jimmy, there was a gap when it was new . And I always run one. And that very well could be the problem. You can re center your barrel and slide the clamps back. You'll just have to reset your bolt probe depth afterwards. If that doesn't cure it…I would try replacing the o-rings in the frame the barrel slides through.

    Link

    jking
    Participant
    Member

    Thanks guys for the comments. Here's another clue that I kind of ignored but I think is very worth mentioning. At some point probably while installing the Huma regulator, re-adjusting the regulator or tracking down a leak I had a little difficulty getting the rear stock screw to go back in after just slightly snugging up front screw. Up until then it went back together perfectly. At the time it was one of those "hmmm, that's odd, oh well" moments. It finally screwed in with a little finessing so not a problem, I thought. It's a sign that the spacing between the two holes has change a little and thanks to RJ and RMguy this got my little wheels turning, took a little push but they did finally start rolling.

    This evening I marked the air tube with a pencil at the forward clamp, loosened up the clamp screws and moved the clamp assembly back, maybe 1/32 of an inch, snugged the hex screws up and set it back into the stock. I could tell the rear screw was now aligned a lot better and it screwed in perfectly as before. I measured the gap between the shroud bushing and the forward clamp and it's now gapped to .043". Of course I had to re-adjust the pellet probe depth but with my machined tool it only takes a couple of minutes. I may have to fine tune the depth because I'm short about 10fps. I was shooting the MKI's at 875 before and after this reassembly and adjustment the velocity was 865.

    I still do not know if this is going to resolve my POI issue but none the less it was a great learning experience. My take away from this to pass on to others before you start tinkering is take a few measurement's. All guns are going to be a little different so I'd for sure get a measurement on the bushing to clamp gap and the pellet probe depth. Your gun is going to be unique to all others so you'll always have a reference to go back to.

    Oh, btw these adjustments have a huge impact on the trigger. Your trigger may lose a definite second stage wall or the gun my not cock at all.

    JK

     

     

     

    Link

    Rj
    Participant
    Member

    Hope that straightens out the poi shift for you. Let us know if that was the culprit. I also don't really snug the clamp screws down until I get about 100 bar in the tube. Just in case there could be any expansion movement.

    What bar and how many shots are you getting with your current setup?   I've run the MK 2' s at 900 @ 165 bar. But shot count wasn't worth the extra smack.

Viewing 5 posts - 1 through 5 (of 5 total)

You must be logged in to reply to this topic.