SpudFiles

6mm airsoft BBs and 1/4 ball bearings fit nicely inside of a 5/16 metal brake line. With the ball bearings use a magnet to hold them in place.

brandon2513 wrote: ↑

Sun Aug 25, 2019 12:17 am

6mm airsoft BBs and 1/4 ball bearings fit nicely inside of a 5/16 metal brake line. With the ball bearings use a magnet to hold them in place.

Airsoft pellets average about 5.95-6.03mm and store bought 1/4" ball bearings are 6.35mm, so theres a bit of a size difference. Assuming the brake line is nearly airtight with the bearings it would have to be a pretty loose fit for airsoft, far looser than a store bought 6mm barrel.

I'm currently on the hunt for a good barrel for the 1/4" slingshot ball bearings. I'm looking for air tight interference fit. Closest I've found so far is a copper pipe at 6.5mm inner diameter, sadly its as thin as a staw which results in effortless bending.

Xamllew wrote: ↑

Tue Feb 11, 2020 8:51 pm

I'm currently on the hunt for a good barrel for the 1/4" slingshot ball bearings. I'm looking for air tight interference fit.

Assuming your bearings are really 1/4", you can make your own using a 1/4" reamer and maybe a 6mm. Start with some 6mm ID thick wall tubing, if it's the welded crap with a seam on the inside, run a 6mm reamer through it to remove all the crud. Then run the 1/4 reamer through it. Having access to a lathe might help, and if it's a long barrel you will need an extension for the reamer(s).

mrfoo wrote: ↑

Wed Feb 12, 2020 2:03 am

Xamllew wrote: ↑

Tue Feb 11, 2020 8:51 pm

I'm currently on the hunt for a good barrel for the 1/4" slingshot ball bearings. I'm looking for air tight interference fit.

Assuming your bearings are really 1/4", you can make your own using a 1/4" reamer and maybe a 6mm. Start with some 6mm ID thick wall tubing, if it's the welded crap with a seam on the inside, run a 6mm reamer through it to remove all the crud. Then run the 1/4 reamer through it. Having access to a lathe might help, and if it's a long barrel you will need an extension for the reamer(s).

I had considered doing similar to a brass airsoft barrel as they're easy to get a hold of. My idea was to simply cold ream the barrel by hammering a 1/4" bearing through it. Crude, but without a workshop it might suffice. If it does work it would give me nearly the tightest tolerances possible.

McMaster Carr have this in brass https://www.mcmaster.com/8950k552

farcticox1 wrote: ↑

Thu Feb 13, 2020 4:56 am

McMaster Carr have this in brass https://www.mcmaster.com/8950k552

Just wanted to say I went ahead and ordered a piece of this and is an excellent airtight fit for store bought 1/4" slingshot ball ammo, airsoft barrel wall thickness, arrived un-bent too. Good find!