Mod Kit for the HK416 50rd Drum Tower

It has come to our attention that the HK416.22 50rd drum may be seated too low in your rifle possibly causing feeding issues. We have found that depending on the make/model of your 416.22 firearm, the drum may not be sitting high enough in the mag well. We are unable to identify models individually because some will have issues, while someone else with the same model are not experiencing any issues.

Resolution: In order for us to be able to get the issue fixed as promptly as possible, we have come up with a quick fix. We have inserted a set screw into the lock in notch allowing the drum to sit higher in your bolt. We are in the process of making a small adjustment to the mold for a permanent fix.

Here are the steps we took:

1. Drilled a hole using #44 bit through the upper lip of the lock in notch, centered.
2. Used a 4-40 x ¼ tapper and tapped hole.
3. Used a 0.50 hex allen wrench to insert a 4-40 x ¼ set screw until 2 threads are shown below the lip of the notch.

If you are experiencing feeding issues and already have a screw in place, please follow the instructions below.

1. With the drum inserted into your gun, the feed lip should touch the extractor. You may need to adjust the height depending on the model of your firearm after a few test fires.

As of 3-31-2026, we will be providing the screw (already installed into the tower) and 1 allen wrench with your order.

For those who do not have the mod done and are comfortable modifying your drum, follow the steps above. We are providing “Mod Kits” to you for free on our website. The mod kits will include both the screw and 1 allen wrench.