Roller Bearing

This was perhaps the very first "upgrade part" offered for the WE M4.

Essentially a "No brainer"….a cartridge bearing that replaced the stock solid brass roller. Makes sense and seems like a logical improvement.

The promise was "crisper action" and "lightning fast recoil"……

if the truth was told? It does nothing.

If there is any increase in recoil or 'rate of fire', it is entirely imperceptible.

The other negative is the SHAPE of the cartridge bearing. The shoulders or outer edges of the bearing are perfectly "square".

Meanwhile the channel the bearing rides in (The charging handle) is NOT square, but round. The stock brass wheel has rounded corners and mates with the charging handle perfectly.

The square bearing rides on the outer points, and never rolls smoothly since it isnt mating correctly with the charging handle surface.

Another BAD feature of this particular bearing is the BRASS insert. It is there to reduce the inner diameter of the generic bearing to match the thin metal axle, or "pin" in the WE rifle.

One of the motivations for me to change to a cartridge bearing was to get away from a brass part that is always in a state of "wearing out" - just the nature of a brass part.

Then I get the new cartridge bearing that has - you guessed it - a BRASS insert. Uggh!

This insert began wearing noticeably in the first week - the bearing became wobbly and "sloppy". This protracted the already sketchy action.

Together with the 'shape issue' mentioned above, the action when charging the handle was like riding a motorcycle with a "flat tire". You could feel the bearing "wandering" from outer edge to outer edge as it wobbled.

So the verdict is to keep the stock roller. Skip this particular product. Not recommended.

Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License