Do I need to stabilise this inner barrel?

Hey guys,

In the pursuit of accuracy would it be worth stabilising this inner barrel?
This is not mine but a screenshot of the same one from Bradley Phillips SRC SR4 YouTube review

As you can see it would be lucky to have 1mm of movement between the inner and outer.

Also, if its worth doing what would be the best way to go about it, some electrical tape wrapped around the inner?



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Yes some electrical tape with that little room to play with. :+1:


I might go full science and video the movement during firing pre and post electrical tape.

“The only difference between screwing around and science, is writing it down”

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small green o-ring from P1 repair kit. Push into outer barrel with small blade screwdriver. Eliminates inner barrel movement

Absolutely always worth stabilsing any inner barrel. The more solid your setup, the better your accuracy and reapeatability. :+1:

I learned the hard way that in order to achieve good air seal, it’s best you make sure there is no movement between:

  • the nozzle and t-piece,
  • the t-piece and inner barrel,
  • the inner and the outer barrel,
  • the outer barrel and the handguard, upper body, barrel nut/adapter.

Thanks Wombat.

No shortage of Green O-ring kits out there, but for the uninitiated, what specifically is a P1 kit?

The green o-ring kits were originally sold for the Kublai P1 GBB pistol

Thanks, wouldn’t have worked that out in a million years.

This guy?

It’s also worth keeping in mind too that if the barrel is stabilised to the outer too tightly it’s possible that it can shift forward slightly and stay there. That’ll result in a bad airseal.

The spring on your barrel in front of your t-piece is designed to hold it in the correct position relative to the rubber nozzle… if you stick your finger in the magwell you should be able to push your t-piece forward and it should reseat back to it’s home position under spring tension. While it doesn’t really move under fire, if it’s tight it might do with repeated shocks.

A neat but free sliding fit is what you should be trying to achieve.

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Excellent advice, thanks