A Noob's Hop Up story!

[Airsoft Related Nickname]

I am a noob and I'm ok with that but you may have to be fairly patient with me when it comes to terminology

I decided to replace the hop up rubber in my SRC G36c. I ordered a Madbull blue 60 degree rubber with an x spacer off the Bay they call E. Adjusting my hop up one way or the seemed to be making very little difference and this seemed to be the way to go.

Here I will quickly skip to the end so those of a nervous disposition can avoid a greater shock once they are emotionally involved in this story. The new rubber is now in the bin along with several shards of it that I somehow sliced off with my giant fists of ham.

Following a guide to stripping the gun and hop unit down that I found on the internet, the first problem I encountered was thus. Nobody mentioned I had to take my flash hider off to remove the inner barrel from the outer. Working this out for myself left me with a strange and alien feeling that someone more enlightened might call "self satisfaction".

From here it was but a few moments work to follow the guide, strip down the hop, replace the hop rubber and then completely bork it up trying to get it back in!

Not all is lost however! For at the expense of a £7 bit of rubber I garnered some valuable information!

The SRC G36c does not take an "x" spacer. In fact it doesn't take any spacer! The reason for this is that the little nub thingy already ends in an x shape. Neither a flat spacer or an x shaped one would fit or even be required.

The second piece of information to be gleaned from this debacle is that the hop up unit is not very efficient. Adjusting it basically does this:

Nothing. Nothing. Nothing. Nothing. Nothing. Ooh a tiny bit of rubber pokes into the barrel!

It just isn't very well made. A point corroborated by the bits of silvery chaff that fell out of it once I took it off. Basically the nub needs to be about one millimetre longer or the cam of the adjusting wheel needs to be more pronounced.

So now I am on a fairly casual hunt for something, not necessarily the right thing, to replace the nubby thing with!

On the bright side though my new 9.6v battery and Burst Wizaed are awesome!

 

[TacMaster]

I have the same problem with hop adjustment after installing my new madbull tightbore, there's a little square cut out in the end of the barrel which goes into the hop unit so the cam can put backspin on the BB;however there is literally no change to BB flight even at full hop. (i am using the stock rubber which gives me decent accuracy out to 30m)

So should I swap out the rubber for a madbull brand, or should I do some jigging with the barrel and re-install it?

 

[Airsoft-Ed]

I'd try reinstalling, Tac.

Could be that the nub that presses on the rubber isn't in the right place, the hop arm might not be sandwiching it between the arm and the rubber, it might've missed it completely. Or you might've inadvertently twisted the barrel as you were putting it back in, so that the hole in the barrel is no longer aligned with the hop nub in the unit. I do it all the time. Installing hop rubbers so that they sit correctly can be a massive pain in the arse, it's rarely a case of just swapping it over and putting it back together. At least not in my experience.

ARN, have you looked into the SRC G36's hop unit compatibility? You might be able to buy an entire new hop unit as opposed to just a new rubber. That ought to sort all your issues out. Or you could try modding the existing hop unit to make it work better.

Know exactly what you mean about that sense of self satisfaction as well haha

 

[Airsoft Related Nickname]

I have thought about changing the hop unit but I've kind of got to the point where I don't want to put much more money into it!

I am fairly hopefully that I will find a way to mod the existing unit. I already tried supergluing a shim onto the bottom of the "nub thingy" but the lateral friction of the hop wheel was too much for it.

I can just about get a .20g BB to fly straight out to 50 feet. (the length of my garden) However I feel I should be able to over hop(?) the BB so it lifts...and then dial back from there to get it to go level. I don't like having to have the hop on fully. I would always prefer not to max it out so I have some adjustment. And of course at some point I will move up to .25's and then it will no doubt be hopeless

 

[bigshep]

Have you thought about rubbing the shaped part of the hop arm flat, then installing your hop nub of choice?

Or you could cut some thin electrical tape, or use ptfe tape on the cam to bulk up its diameter and its subsequent popping the hop down into the barrel.

To be honest you do not need a huge amount of rubber poking into the barrel. If you consider most barrels are 6.04mm and most bb's are 5.95mm +/- a tad then you are really looking at 0.1mm max needed to poke into the barrel or you will get stopages.

 

[Airsoft Related Nickname]

I think both of those ideas are worth a try. Maybe electrical tape to the cam might be the best to try first.

I find it so hard to judge the amount of rubber popping through by eye. All I know is that I need to have the hop fully on just to keep level up to 50 feet. I would be much happier if I could gain some more obvious lift.

I will keep trying and hopefully be able to report back with some success

 

[Airsoft-Ed]

When you're putting the rubber in make sure you look down the barrel from both ends once you've got the hop unit and everything sorted, then adjust it to both extremes and check the effect. It can look like it's working well from one end and not so much from the other.

Looking from the muzzle end makes it easier to see if the hop rubber's "skirt" bit is hugging the barrel correctly too. Madbull Blue rubbers are a right nob for having silly massive skirt protrusions into the barrel.

 

[Airsoft Related Nickname]

I have had another quick play with a couple of modding ideas but nothing has really panned out. I could try another rubber...now I have more experience fitting them ... or consider a new unit.

I must admit I didn't think much of the Madbull blue one. Very flimsy and not a great fit. Might try something different next time.

 

[TacMaster]

I'd try reinstalling, Tac.

Could be that the nub that presses on the rubber isn't in the right place, the hop arm might not be sandwiching it between the arm and the rubber, it might've missed it completely. Or you might've inadvertently twisted the barrel as you were putting it back in, so that the hole in the barrel is no longer aligned with the hop nub in the unit. I do it all the time. Installing hop rubbers so that they sit correctly can be a massive pain in the arse, it's rarely a case of just swapping it over and putting it back together. At least not in my experience.

ARN, have you looked into the SRC G36's hop unit compatibility? You might be able to buy an entire new hop unit as opposed to just a new rubber. That ought to sort all your issues out. Or you could try modding the existing hop unit to make it work better.

Know exactly what you mean about that sense of self satisfaction as well haha

sounds like useful advice, I'll try re installing over half term. Fingers crossed it'll work

 

[Airsoft Related Nickname]

SUCCESS!!!

Success?

Early days but I think I have come up with a workable mod! I have taken my ruined Madbull blue rubber and cut out a square the same size as the hole in the hop up that the hop arm goes through. I placed it in said hole and then inserted the hop arm to keep it in place. This extra thickness seems to have given me the extra bit of hop I needed.

Just took a few shots in my back garden and I could see an obvious gradual lift out to 50 feet. I didn't shoot enough to get a feel for accuracy because it's really too windy out there to judge with .20's.

I need to book an hour in a shooting range so I can get my sights zeroed in and hop adjusted but I am pretty confident I have made an improvement.

 

[Ian_Gere]

I just bought an SRC G36KV that I'm guessing has the same hop unit and rubber. I was less than impressed by the range of the stock set up, although i was getting a lot more than 50 feet. I swapped the stock rubber for a CYMA one I had lying around and performance is better, although not so much that I'm satisfied.

Something that occurred to me is that it's pretty cold right now, which must affect how sticky the rubber is (although I test fire out of my back window so, although I don't heat the back bedroom, it's not as cold in there as outside). Anyway, I decided that, before I go spending money which may prove to have been pointless, I'm going to see how the stock unit and CYMA rubber hold up with the new barrel I have planned and it warms up a bit (probably lol).

If anyone is still labouring under the misapprehension that CYMA kit is pants, because it comes from China, let me explain about their hop rubbers: The rubber blob which is designed to poke down into the barrel has a split in the centre, so that when it is pressed down by the nub above, it divides. Obviously the split doesn't go right through the rubber, or it would leak, but the division of the blob into two contact points means that hop is applied equally to either side of the BB, which seems to be very good for accuracy. It's also easier to tell if you have the thing installed centrally, because the split is a much more obvious thing to line up with the barrel than a smooth hump. They don't work well with X or fishbone spacers in an AK hop unit though - they don't need to, they do the same thing with a normal cylindical spacer, but the G36 concave hop arm end seems to fit fine.

I did notice that I couldn't get the brass ring to go back in with the CYMA rubber. The G36 ring does seem a fair bit wider than usual however, so I just used a spare normal one instead. I've had problems getting rubbers on and off before too (ooh er) and have ripped a clear Madbull Shark one. Now I use a smear of oil, I just do my best to keep it out of the barrel and off the contact point.

 

[Airsoft Related Nickname]

Interesting post! I might look into getting a Cyma rubber. I am most impressed with the Cyma handguard and stock I have on my G36c so I would have no qualms about using a Cyma rubber. It sounds to me that the split blob would naturally also protrude further into the barrel which would also help my problem.

And to clarify...I was getting way more than 50 feet in a skirmish. It's just that my garden is only 50" long! However I was getting a visible drop off at that distance. I would guess at maybe a 6" drop off. What I was more worried about was not being able to get any visible lift.

I need to get access to larger space so I can test my modded hop up properly before I know if it's worked or not. But a Cyma rubber is definitely on my list.

 

[Ian_Gere]

BTW, is it a Gen III SRC?

 

[Airsoft Related Nickname]

Yup...Gen III.

I guess long term I might replace the hop unit but for now my "double bucking" seems to be doing the trick.