New hop rubber misfeeding and huge fps variations

[pyromancer6]

I think it's just a problem of the sliding AK/MP5 hops being a pain in the ass - I had to shave down my XT nub to stop my MP5 overhopping 0.28s with no hop applied as it was just a little too wide to fit the tract properly and was getting forced in when the arm went back in place [and the one I cut on the game day on a bench outside fixed this, just it was a little pissed so it was shooting to the left 😅], a fresh XT nub same as the one you linked went in fine after some sanding and a little trimming, same ML macaron rubber too - just in a CYMA MP5 instead of an AK [the hops are pretty similar or at least I'm assuming so]

[JinxDuh]

Looking closer at the nub today, it seems uneven? 

[JinxDuh]

Stuck a stock black rubber in with the xt nub, fps variations from 270 - 298

 

Stock black rubber and nub (From an old m4 I upgraded), 291 - 293 fps

 

Again all on .25g BB’s

[Adolf Hamster]

3 hours ago, JinxDuh said:

Looking closer at the nub today, it seems uneven? 

 

pic #3 looks to be off-centered

 

although that shouldn't be the cause of an fps variation, it's more a curving you're only going to notice on shooting.

[ak2m4]

Perhaps your aeg just doesn't like maple leaf bucking, barrel and chamber combination.  Also did you say your using a Macaron?  The XT barrel does work best with MR due to the larger window size.

 

As always your welcome to return any parts for a refund.

 

Did you get a chance to try the Macaron with an official nub?

Edited June 14 by ak2m4

[JinxDuh]

1 hour ago, ak2m4 said:

Perhaps your aeg just doesn't like maple leaf bucking, barrel and chamber combination.  Also did you say your using a Macaron?  The XT barrel does work best with MR due to the larger window size.

 

As always your welcome to return any parts for a refund.

 

Did you get a chance to try the Macaron with an official nub?

Yeah, using a macaron. The one I got has dots and a wave around it, the other ones I’ve had in the past have been smooth with 3 ridges. Maybe I’ve ordered the wrong rubber 🤔

 

I thought I had a spare omega nub but sadly I didn’t, so will get one ordered

3 minutes ago, JinxDuh said:

Yeah, using a macaron. The one I got has dots and a wave around it, the other ones I’ve had in the past have been smooth with 3 ridges. Maybe I’ve ordered the wrong rubber 🤔

 

I thought I had a spare omega nub but sadly I didn’t, so will get one ordered

The pink/blue is what I have (But it’s yellow), and the yellow is what I’m used to getting. I assume they changed design or something?

[Skara]

That is just to differentiate the older macarons (3 stripes) from the newer super macarons (wavy pattern).

The main difference is the additional supports next to the contact patch and the patch being slightly wider/longer on the super variant.

[ak2m4]

From what you're saying you have a MR, that's the recommended bucking and the one I use to test.

 

However your hop chamber might prefer the Macaron version which uses a slightly smaller contact patch, it's all about trying different things.  it's worth just trimming the feet of the red nub a little or try the MR bucking with the stock nub. 

 

With the inner barrel and hop chamber outside of the gun apply the hop and look down into the barrel and see what the contact patch is doing, should give you an idea

 

 

 

[JinxDuh]

Fitted the rubber and nub that came with: https://www.ak2m4.co.uk/zci-rotary-hopup-chamber-plastic-m4?search=ZCI Rotary Hop-Up Chamber Plastic

 

Stable fps throughout adjusting, peaking at 312.6 fps (On .25g bb’s) 

[The_Lord_Poncho]

I've used those ZCI blue buckings that come with their hop units before in similar circumstances when the gun seemed to be misbehaving with other 'fancy' buckings (maple leaf, unicorn etc) with good enough results.

[JinxDuh]

3 minutes ago, The_Lord_Poncho said:

I've used those ZCI blue buckings that come with their hop units before in similar circumstances when the gun seemed to be misbehaving with other 'fancy' buckings (maple leaf, unicorn etc) with good enough results.

I’m going to leave it as is for now, take it with me next month and see how it fairs. I have an omega nub ordered too just in case it’s still not great. The original set up was shooting up and to the far left, so it can’t be much worse 😂

Put a standard black nub and bucking into my fathers E&L too and all of his issues stopped, no huge variations and no “no feeds” and double/triple etc feeds. Seems E&L’s just don’t like MR buckings or XT nubs. I plan on getting one of the Begadi rotary hops eventually so I’m assuming it’ll be a case of trial and error with that one too

[ak2m4]

I think for ak there's a vfc plastic rotary that's really good if you can find one, only about £15.  Maybe some AK owners can confirm this

[The_Lord_Poncho]

Coincidentally I was trying to sort out a gun this morning that was shooting off to one side with a ZCI rotary and an Mr hop. After discounting the barrel being rotated to the side in the hop unit, swapping out the nub etc with no change, I realised something quite interesting. The hop arm on the ZCI unit had been poorly moulded. It appears moulded in two halves - and on my version, the two halves were not perfectly aligned. This resulted in a small step halfway across the 'cup' where the nub sits under the arm, therefore placing quite significant uneven pressure to the nub. 10 seconds of careful scraping with a blade sorted it, and now the gun is shooting dead straight. I've used ZCI units in most of my guns with good results, so this was a first for me. Had me scratching my head for a while!

Edited June 15 by The_Lord_Poncho

[Colin Allen]

20 hours ago, ak2m4 said:

I think for ak there's a vfc plastic rotary that's really good if you can find one, only about £15.  Maybe some AK owners can confirm this

The Begadi hop is excellent.

[JinxDuh]

36 minutes ago, Colin Allen said:

The Begadi hop is excellent.

Have you had one fitted in an E&L at all? Curious if you had to change the nozzle out if so

[ak2m4]

1 hour ago, Colin Allen said:

The Begadi hop is excellent.

Have you tried the vfc Colin?  Interested to know what you think of it.

[Adolf Hamster]

Tbh, i found the e&l standard units to be pretty decent, i wouldnt say changing it out is strictly necessary

[JinxDuh]

57 minutes ago, Adolf Hamster said:

Tbh, i found the e&l standard units to be pretty decent, i wouldnt say changing it out is strictly necessary

 

Well, my AK was firing straight up into the air and way over to the left - From brand new. Hence why I decided to change the rubber for an upgraded one, and the nub too - Neither of which seems to work with the E&L hop unit lol

[Colin Allen]

3 hours ago, JinxDuh said:

Have you had one fitted in an E&L at all? Curious if you had to change the nozzle out if so

I haven’t, but you shouldn’t need to change the nozzle.

2 hours ago, ak2m4 said:

Have you tried the vfc Colin?  Interested to know what you think of it.

I haven’t; my hop unit of choice used to be Combat Union, until the QC fell off a cliff and then Putler invaded Ukraine.  The Begadi one works very well.

[ak2m4]

2 hours ago, Colin Allen said:

I haven’t, but you shouldn’t need to change the nozzle.

I haven’t; my hop unit of choice used to be Combat Union, until the QC fell off a cliff and then Putler invaded Ukraine. 

Da comrade.. 🙂

[Adolf Hamster]

2 hours ago, JinxDuh said:

 

Well, my AK was firing straight up into the air and way over to the left - From brand new. Hence why I decided to change the rubber for an upgraded one, and the nub too - Neither of which seems to work with the E&L hop unit lol

 

Its always possible that something has changed, but i never had issues with the stock e&l hop with the good ol' macaron omega combo.

 

Although tbf my base ammo weight was .32's at 1j so usually my priority was getting more lift.

[Skara]

I do have an E&L begadi hop that I'm not using....

Though with postage from here and customs I don't know how convenient it can be for you.

[JinxDuh]

6 minutes ago, Skara said:

I do have an E&L begadi hop that I'm not using....

Though with postage from here and customs I don't know how convenient it can be for you.

 

Where is it being sent from, and how much?

[JinxDuh]

Fitted the omega nub with the maple leaf bucking, 298 - 307 (.25g bb’s, adjusting hop incremental and only a tiny drop) 

 

Seems I’m now on the right path, so fingers crossed all is good next month 🙏