Barrel Machining. Transfer ports.

[Lanky94]

Evening all.

When machining a transfer port on a new barrel, what is the best tool to go though with to avoid burrs in the chamber?

If a pellet that is pushed though is damaged, what is the best tool to remove the burrs please?

Thanks

[Ca_Varminter]

For FAC porting over in the States

Using my Small CNC Mill....
I first use a center-drill to make the initial port and pilot hole


Then I use with a sharp Carbide End-Mill fully cut and shape the Through Port


Then I follow up with a diamond burr in a pin vise, to remove any speck of burrs.





Good Luck,
Stuart

[KevG]

its also possible to use drill bits as long as good quality.i start with centre drill then go through in increments..say your wanting a 4mm port hole start at 3mm then 3.5 then finish with 4mm.always best to polish over inside of barrel around the port area with a small modeling file.normaly then finish of with a bronze brush like you get in the cleaning kit.clean barrel then rod a few pellets through before re fitting and check the pellets for any scuffs or nicks.a good pillar drill or Miller will do the job.
KevG

[Lanky94]

Awesome stuff.

Thanks chaps.