Hop up wont disable

[BrightCandle]

Gun is G&G CM16 Carbine. The hop up is set all the way to off. At 5m the rounds are in the black on a paper target, however when I go out past about 7m the rounds are landing higher. At 10m I am finding the rounds are 3cm higher than the aim point. Admittedly the spread is also about 3cm's as well but its consistently above the aim point for all rounds.

 

I am assuming this is the hop up doing its thing too aggressively. Should I be expecting a flatter trajectory than that or will it tend to flatten out at longer range as the velocity drops off? Because I can't adjust the sight any lower and I can't turn off the hop up anymore as its off/minimal already. I don't know how this is going to handle at realistic ranges and I seeing as how its dark CQB I wont be able to see during the game where they land.

[Unrustle_Thine_Jimmies]

Take out the hop up chamber and look down the barrel- If there is a Hop up mound protruding then there might be something wrong with the adjustment mechanism- some G&G CMs did have problems with the hop up just jamming on certain levels though I've only seen it in a few friend's guns.

[Mike636]

BB's just like real bullets dont have a truly flat trajectory so 3cm at 10m is pretty good I'd of said. I set my hop up so the BB's get their maximum distance and just aim a bit lower in CQB,

[RR01]

10 metres is way to short a distance to zero your sights. You need to zero for at least 40 metres, then hold under for shorter ranges, although when shooting at a man sized target anywhere on the body is a good enough hit for a kill.

[dex]

Sounds like the hop nub arm is jamming. You may need to take the hop apart and make sure the arm springs back freely. Could be some cack in it. I recently fitted a Lonex hop unit to an AEG and I had to sand a shade off the sides of the hop arm to get it to move freely.

[BrightCandle]

The hop up wasn't stuck, or at least once I got it out and fiddled with it all was working as it should. I took the gun apart to replace the spring to reduce velocity and well now I have the opposite problem, the gun shoots very low and no amount of hop up and sight adjustment corrects it! Sigh. 3 feet low at 10m is a problem.

[Lozart]

The hop up wasn't stuck, or at least once I got it out and fiddled with it all was working as it should. I took the gun apart to replace the spring to reduce velocity and well now I have the opposite problem, the gun shoots very low and no amount of hop up and sight adjustment corrects it! Sigh. 3 feet low at 10m is a problem.

 

Sounds like you've lost way more than your desired amount of FPS. Check your airseal is good.

[BrightCandle]

Looks like the problem might have been nub displacement as it came out when I disassembled again.

 

One thing I do notice with this hop up is that off doesn't mean no nub protrusion, its already sticking a reasonable way out on off. So I suspect that this is the reason the hop up wont disable and why I was getting so much climb before. I am rebuilding with an SHS M90 spring so hopefully that will restore the FPS and get the gun shooting well again but below the requirement and I will have to live with the gun being overhopped, get a smaller nub or get a replacement hop up.

[BrightCandle]

Reassembled hop up and reseated the buckling and with a new spring its about 3cm too high at 10m, which is exactly what it was before the spring change so all is right with the world.

[BrightCandle]

So I decided to see if a H nub would change the situation with my over hopping. So I bought the light and heavy H nub made by element and fitted the heavy one today. With both .20 and 0.25 BB's I seeing less hop being applied by default and the groupings are much more consistent vertically. I no longer get a slight nub protrusion from the outset.

 

The difference in performance is mostly consistency. I could get groupings of about 2.5cm before but they would be higher than the sight and I would get about 4/10 fliers that would be in and around a 8 cm radius, both vertically and horizontally. I tried the same firing test with the H nub and the grouping was 10/10 within the 2.5cm, so all the inconsistent rounds that made a wide pattern are completely gone. At 10 metres I can now shoot through the same hole all day long, its quite incredible. It seems to work a little better with the heavier 0.25 BBs that the 0.2s but it has had an effect on both.

 

Mighty impressed with what is basically 10 minutes of time and a £1.50 for a simple upgrade that makes a massive difference in the spread of rounds landing.

[Lozart]

So was that the white nub or the black one?

[BrightCandle]

I got from land warrior, its a dytac H hop spacer large, I replaced the G&G nub and just stuck it there with some silicon lube. Its black and hard plastic, the g&g nub is a rubber piece with a hole through the middle and just a basic cylinder. I also sealed around the barrel with silicon lube on the bucking and the hop unit as it all went back together.

 

I will try the dytac small h nub at some point but I will want to try this in a game to see what it does at range and what adjustments I will need to the setting.