Nozzle/Barrel Alignment
If you’ve worked on AEG’s, you’ll likely have encountered alignment issues between the inner barrel and the nozzle. This misalignment can cause the nozzle to drag along the hop-up chamber, creating unnecessary wear, reducing feeding reliability, and potentially issues with compression!
An easy way to check alignment is to remove the hopup chamber, then install just the gearbox and inner barrel. Assuming there is little play in the inner/outer barrel, this should give you a good indication of the alignment of the two parts! In this case, the gearbox does not line up with the inner barrel and will need an adjustment installed!


By using a matched-length headless screw (all-thread) you can have a rigid adjustment that lets you set the left-right alignment of many types of gearboxes in addition to a bit of extra rigidity in the receiver as the screw acts as a brace between the two halves.
You'll Need:
- A headless screw (M3 all-thread) with enough length to cut to the width of the receiver.
- A long regular screw can be cut and used as well!
- A nut to secure the screw that will fit between the receiver and gearbox.
- Brass-standoffs work well as they can be easily cut and shaped.
- Locktite to secure the screw in the threaded half of the gearbox to hold the adjustment during service disassembly.
Start by:
- Measuring the width of the receiver where the screw will sit, cut/grind it to length, and then polish the ends to reduce scratching and scraping.

- Install the screw into the gearbox with the nut to tighten it down, then fit the shell into the receiver to check initial alignment.
- Calipers can save time by measuring the width of the receiver and gearbox, then splitting the difference to center the screw.

- Remove the gearbox and turn the screw in/out to adjust where the gearbox sits in the receiver.

- When you have the adjustment correct, a bit of locktite will hold the screw in place when removing the nut for servicing, then do a final install and check of the nozzle alignment.

If you did it correctly, the gearbox should naturally fit snugly in the receiver and have perfect left/right alignment with the inner barrel of the gun!