M4 Hop Up Arms - A Comparison & WTF

[Rabbit]

I've been sitting at my bench going over different standard m4 hop up chambers and applications with a flat hop.

Sadly I managed to tear my grey Modify Baton Ryusoku (sorry Pesto) as well as another due to jams and not being as careful as I could have been.

This led to finding a replacement for the Lonex unit I was using, which then in turn brought up further questions and configurations.

As you can see in the pictures - the hop up arms are completely different in angle of engagement when the nub/flat nub is applied to the hop up bucking.

I'm going to assume this can affect range and consistency and reasons why some hop up units appear to be better than others - and more importantly to me - which arm can better apply more engagement when it comes to a flat nub.

Edit: Yes - the Lonex & Prometheus Neo arms are spot on with each other

Whats the deal here? What arm actually delivers the better results with a flat nub and/or standard nub???

[pestobanana]

Sorry to hear the barrel group didn't work out. Hopefully it performed well before it met its fate.

As for the arms, the angle that the nub holder is at makes no difference since flat and bridge nubs nubs are designed to be self leveling. What will matter is if the nub is centered in the barrel window. The best way to test this is to put your barrel in the hop up unit without a rubber, and put the clip in. This will show you where the barrel window is going to sit. Pick the arm that has the nub closest to the center.

[Rossco66]

I put a touch of lubricant on the hop up arm to hold the flat hop nub in place while I install it. I figured it would help in the self leveling as well.

Has anyone ever experimented with a patch that maximizes the barrel window coverage within the hop up chamber window? Even the flat hops, after trimming to fit, don't seem to cover all of the barrel window. I suppose they are close but I just thought I would see if it has ever been done.

I would envision an additional material that is thin but somewhat rigid sitting directly on the bucking covering the entire barrel window rather than be attached to the hop up arm. The flat hop nub would push down on this separate piece when hop is applied.

[pestobanana]

Originally Posted by Rossco66

I put a touch of lubricant on the hop up arm to hold the flat hop nub in place while I install it. I figured it would help in the self leveling as well.

Has anyone ever experimented with a patch that maximizes the barrel window coverage within the hop up chamber window? Even the flat hops, after trimming to fit, don't seem to cover all of the barrel window. I suppose they are close but I just thought I would see if it has ever been done.

I would envision an additional material that is thin but somewhat rigid sitting directly on the bucking covering the entire barrel window rather than be attached to the hop up arm. The flat hop nub would push down on this separate piece when hop is applied.

That exists, but in the form of a nub meant for R Hopped barrels. With that amount of effort, you might as well just R Hop the barrel.

[Rossco66]

I've actually been having good success with a Flat Hop set up with an RHOP patch installed. I hate dealing with the nubs like the HS5 one and found the flat hop nub far less of a pain in the ass to deal with.

I also like the fact that I don't have to do irreparable modification to my hop up arm in case something new comes down the pipe in the future.