Weird FPS in my Tavor...?

Discussion in 'Gun Building, Modifications & Repairs' started by Kuratosu, Jun 3, 2021.

  1. Kuratosu

    Kuratosu Member

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    So, with help from the community, I was able to fix my CTAR Tavor and get it together/feeding/running. I loaded up some .28s and tested the FPS on my Acetech BT Chrono. When I first fired it, at first the bb fell out of the end, then as I kept firing, it registered around 80FPS, then 120FPS, then it jumped to 220-290, then bounced between 250 to 330FPS. Now it is firing at a solid 334 FPS.

    So I'm wondering, is this normal? Did the gun need time to let everything seal up or something? Perhaps I need to lube something I missed?
     
  2. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    OR perhaps you put in too much lube and it was messing with your piston seal.

    Without knowing what you lubed and with what lube we can kind of guess.
     
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  3. Kuratosu

    Kuratosu Member

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    That... would make perfect sense lol. I used Super Lube 92003 silicone lube with PTFE. I heard that was the best to use so I used a small amount of the cylinder/piston head and a bit more for the gears.

    On the plus side, I ended up ripping apart my Godzilla 5000 motor and swapping a short motor into it. It worked so now it all works great. No weird noises or anything. So I wanted to say thank you for all the help you've given me. I really appreciate it.
     
  4. GrimWolf0770

    GrimWolf0770 Active Member

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    Hit it with a hammer a few times........that will "fix" it.
     
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  5. Kuratosu

    Kuratosu Member

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    Lol, that's one of the things I've done to my tavor in the process of modding it. Even took a sawblade to it to make a Maxx ME Hopup fit/feed in it.
     
  6. GrimWolf0770

    GrimWolf0770 Active Member

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  7. GrimWolf0770

    GrimWolf0770 Active Member

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    I have a German Shepherd that likes to eat airsoft guns! would that help? ^~^
     
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  8. Kuratosu

    Kuratosu Member

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    o_O How fast would he chew through Nylon Reinforced Polymer? I would guess that it would take a lot longer than ABS but not as long as pot metal or aluminum lol.

    Also, that's really unfortunate. What guns have you lost to him?
     
  9. GrimWolf0770

    GrimWolf0770 Active Member

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    I've not lost any but I've had to replace a grip on a m4 and there are teeth marks on my full metal we 84 . and yes I mean the metal. X~X he also draged my pp2k outside but he had it by the stock but its steel so its ok.

    Btw polymer with nylon would never hold up to any dog bite for long let alone my white terrorxD
     
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  10. GrimWolf0770

    GrimWolf0770 Active Member

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    Come to think of it I have 4 guns need fixing by June28 and I need a vest, mask goggles..... God am I lazy.....
     
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  11. Shadowbane

    Shadowbane Active Member

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    You may have a cylinder with a hole in it, which would cause a suck back. It takes some running through BB's to get it to work right.
     
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  12. Kuratosu

    Kuratosu Member

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    I believe the over abundance of Super Lube was probably the issue since the Tavor fires a solid 334fps now without any issues. Also, the cylinder head is offset so I had been staring at it for quite a while trying to figure out what might work. I'm considering having someone CNC a better version for me since the stock is proprietary from what I can tell.
     
  13. Shadowbane

    Shadowbane Active Member

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    No, I am talking about cylinder with a hole in it.
     
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  14. Kuratosu

    Kuratosu Member

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    Yeah, I know what you meant. I just tried to say that I checked it before I stuck it in there. I was going to swap it out for a Maxx model Cylinder but because it was offset, I spent a good amount of time looking at everything about it to see if there might be a way I could mod the new one to fit. So I've made sure it doesn't have any holes.

    Plus, if it had a hole, I would be seeing a drop in FPS due to compression issues. At the moment, I am getting 334fps with .28g BBs. Which is basically 395fps with .2s, so there's definitely no problems now lol.

    edit: Punctuation.
     
  15. Shadowbane

    Shadowbane Active Member

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    Good edit. I am glad your gun is working right now.
     
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