Barrels, Sleeves to reduce I. D. At gel entry

See that China have came out with sleeves that go in I’d of entry of barrel to reduce down further I. D. and maybe hold gell back for more compression. Hard to translate, one seen was from 7.5 to 7mm.
What ya Rekon.?
Gimmick?, add consistancy in fps.
Better fps?,

I’d thought about this a while back when I was looking to redesign the nozzle t-piece interface.

Gels being slippery and malleable, will indeed get held back until there is enough pressure to force them through, then it’s business as usual.

My expectation is an increase in shredded gels at the start of the barrel (reduction of ID to great) or reduced accuracy (damaged gels or turbulence created at the sleeve)

Curious to see though

I would like to see someone make a .001 mm thick sleeve out of aluminium or anything else and be able to push it down an inner barrel at all, let alone not damaging it.
Then, once in place, I would like to know how to retain it in place… and lastly, where they will get gels of a constant enough size to make it work (and be worth it)

I would say, this is simply a ‘pipe dream’ (see what I did there? :grin: oh, never mind…:roll_eyes:avatar_22


I seen 2x types one was longer,
Thought it goes up into tee length as well as barrel.
The other was just in barrel.
I did this sum time ago, when had batch of smaller gels. I didn’t hav a chrono.
But do now.
Can’t remember if notice difference.
I thought was nothing new when seen.
I can do from 7.5 to 7. 2.
Mite give it a crack today.
Grown sum war interest to about 7.2 to 7.3.

Prob by the look about one seen looks about 30mm long, Guestimate 20 into T and 10 in barrel.
The other version seen only 15 to 20?.
Slightly diff, only went into barrel.
Off the shelf, for a part to do is difficult.
Too tight tolerances if standard 7.5. I’d.
I can do it but mod internal I’d, to make work.

Small test results, yeah nahh.
Spose depends if small gels.
Didn’t grade mix bag, 7.1 to 7.4.
Any how sleeve gave cupla breaks.
Less fps.
Non sleave, better fps no breaks.
Barrel is 7.5 I’d
Sleaved 20mm long 7.2 I’d.
Ran and swap few times.
Here’s last cuple chrono.
Results consistant between tests.

can’t argue with the results.

not terribly surprised though

And my sleeve not as severe drop like wat seen they market, go from 7.5 o 7.0.

can you show a pic of the sleeve not in the barrel?

Sorry bruz,
If visualise,
Basicly, to make work and remain sum wall.
Bore out I. D. Of barrel and length to suite sleeve.
I had small off cut from a 7.2 barrel.
Honed down od. To fit in now a barrel recess.
Put a chamfer on the entry.
Slight tidy on the exit of sleeve.

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Yes, but what do you bore (accurately) the barrel with? How does the sleeve manage to arrive straight? I cant even get a barrel to arrive straight usually? I don’t know how you can get a .001 sleeve delivered? :thinking:

No worrys bud,
Lost me how arrived
At 0.001

Well to make a 7.5mm barrel down to 7.2mm means the sleeve is pucking thin?

What did you bore the inside f the barrel with to get it accurate? (the boring) what sort of bit or tool?


Found better translated description.
Marketed as a ball stopper stop gels falling outa barrel.

If the correct size gels are used then gels falling out of the barrel is not an issue that needs fixing

Finally worked out on pH.
To change to jpeg to upload.
Product seen.

Short barrel? ???


I hv one of this installed. I hv test it with 7.5id 35cm long barrel, 1.3 unequal spring. There are some random gels breaking that seems to appear when I increase my hop. So, i just tune the hopup until no more visible gel break. Accuracy wise is okay-ish (i am sure i can get even tighter grouping with 1.2 spring), but I dont know if without the gel stopper (sleeve), I can tune more hop and get improved accuracy & range. Hopup used is rizer R1 nylon with metal tongue.

Thanks for sharing m8.