Hop-up assembly 

You can use T7 you just need to push it in very hard

you can add a grub screw to the barrel if drilled and threaded correctly, this will eliminate any hop movement when the rif cycles

Did you ever figure it out? Having trouble with mine.

You gotta be rough with it. That’s what I did

i tried it now and it doesnt. It will require filing of the hopup unit to properly align with the feeding tube for bbs to flow, and I will also have to file around the air nozzle receiving portion, the airnozzle cannot come forward because its either too tight or its crooked. If its crooked then it might not work at all.

Just opened mine and it did not come with the nub

Regular Version (Metal Machine Gun) Not suitable for Featherweight and other plastic machine guns. Featherweight bullgear.net/hop-up-featherweight-s-t They are different. You don't know what you're saying A&K MK46 they come in all kinds!!!

When is the featherweight unit coming out? I preordered on website, but it would not let me purchase!!!

@@blue24_actual It's available now. Just received mine in the mail.