Zci barrel causing misfeeds and jams are mad bull barrels any good

[steverebo]

So my ZCI barrel is having issues with my lonex 200 round pmags it's misfeeding a getting blocked I've tried prometheus bucking malle leaf macrom a MR HOP with the same result.

I want to use my lonex mags so will have to grab a new barrel, the maple leaf 290mm is out of stock everywhere so I was looking at the mad bull black python v2 us this any good? If not could someone recommend an alternative 

 

[Asomodai]

Can BBs enter the hop end of the barrel when you insert them manually? If so it would suggest a different issue. Mad I'll barrels in my opinion are worse then ZCI. 

 

[steverebo]

Yep, only happens with my lonex mags i get dry firing and eventually a jam, they are higher capacity 200 round midcaps whereas my other mags are 140 round or high caps they all work flawlessly but when I put my stock barrel in my linex mags feed fine

 

[Iceni]

Madbull barrel is garbage. I got duped into one years ago, and it was good for about 3 shoots till the coating started to wear out and it would sling BB's all over the place.

One thing you should check on the ZCI is the window. They can sometimes have a burr on the inside.

If you have access to one a countersink may be the correct tool to just add a little chamfer to the feed end on the barrel. It might make the BB's feed a bit better. You don't want to remove a lot of metal just a skim to give it a little feed angle. The 12mm one in this pack should fit. Pop it in a drill and use a very slow speed and just touch it in, Don't be tempted to go fast - Stainless isn't like other steels and will work harden if you get it hot.

https://www.amazon.co.uk/Gasea-Shank-Degree-Chamfering-Countersink/dp/B07GB524J7/ref=sr_1_6?crid=3QOSKIXWGZXJ&keywords=countersink&qid=1643758732&s=diy&sprefix=counter%2Cdiy%2C69&sr=1-6

 

[Asomodai]

Yep, only happens with my lonex mags i get dry firing and eventually a jam, they are higher capacity 200 round midcaps whereas my other mags are 140 round or high caps they all work flawlessly but when I put my stock barrel in my linex mags feed fine

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Sounds like you have midcap syndrome. When you half fill the Lonex mags do they feed fine? 

If so, its more likely the nozzle. 

 

[steverebo]

I am using a rocket 21.4mm nozzle would grabbing 21 3mm nozzle help fix this qnd maybe a new tappet plate and spring?

 

[concretesnail]

Unless the barrel is sitting too far back into the hop unit I doubt the barrel is the issue, if it were then all of the mags would feed poorly.

As Asomodai mentioned its likely midcap syndrome and nozzle combination.

 

[steverebo]

Unless the barrel is sitting too far back into the hop unit I doubt the barrel is the issue, if it were then all of the mags would feed poorly.

As Asomodai mentioned its likely midcap syndrome and nozzle combination.

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It's definitely only the high capacity mid caps that I have that are having feeding problems.

How do I fix mid cap syndrome?

Would a shorter nozzle new tappet spring and new tappet plate help?

 

[concretesnail]

It might be foxed with a new tappet spring, or cutting a loop or two from the spring you have in already, to tighten it up and put more tension on the nozzle.

But

If you try not filling the mags completely and the issue resolves then I'd look to either bind or clip the magazine spring if it's a magazine that's already had significant use. If however it's a new magazine I'd try filling it completely, and leaving it a while, then trying again as the time spent under compression will take some if the strength out of it.

 

[Iceni]

Whoa guys!

The gun is feeding fine on one barrel with the same feed nozzle and hop unit. It's only the barrel change that's causing the issue. Feed nozzles only go into the hop and touch the barrel. Therefore the issue isn't feed nozzle, tappet spring, Midcap syndrome, or hop unit.

The issue can only be the barrel. So it's either got an issue like a crushed feed, Or more likely a burr or there's a little too much material on the feed side of the barrel and it's allowing the BB to lock up once it enters the lips but before it enters the barrel. Hence Chamfer it first and rule that out! It is probably that the failing mid caps have a little more upwards pressure, and it's allowing the BB to enter the barrel by rolling on the top of the feed... That position is the one that needs the attention.

 

 

[steverebo]

Whoa guys!

The gun is feeding fine on one barrel with the same feed nozzle and hop unit. It's only the barrel change that's causing the issue. Feed nozzles only go into the hop and touch the barrel. Therefore the issue isn't feed nozzle, tappet spring, Midcap syndrome, or hop unit.

The issue can only be the barrel. So it's either got an issue like a crushed feed, Or more likely a burr or there's a little too much material on the feed side of the barrel and it's allowing the BB to lock up once it enters the lips but before it enters the barrel. Hence Chamfer it first and rule that out! It is probably that the failing mid caps have a little more upwards pressure, and it's allowing the BB to enter the barrel by rolling on the top of the feed... That position is the one that needs the attention.

 

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I have noticed that when it jams there are 2 bb's trapped and they don't move at all no matter how many times I fire

I might just grab a new maple leaf barrel but the 290mm is out of stock everywhere so may have to grab the 310mm and have an extra 16mm sticking out 

 

[Iceni]

Spot on it's feeding at least then.

Might be a dodgy barrel, Check the window for burrs. And drop a few BB's through the barrel to see if there is a spot where it catches.

To inspect the window - have a poke about at the edges see if there is a wire edge that has folded - remove with a small file or sandpaper.

Check the corners, harder to repair but a bent square micro file can get into those from the top to just round them out.

Clean it with some IPA and give it a decent scrub, might be something sticky in there that's picked up some swarf in manufacture.

Or send it back, If you got it from somewhere reputable like AK2M4 I'm sure he'll be more than willing to replace it since it feeds but does not shoot.

 

[Rogerborg]

When BBs do shoot, how's the hop on them?  I'm wondering if they're just not making it past the hop rubber - and I have read the thread, and am looking at the barrel as the culprit.

If it's a feeding problem, I've had some luck with hand-drilling a very slight detent into the top of the hop chamber.  6mm drill bit straight up the feed tube, a couple of turns by hand, just enough to create a tiny dome at the top of the chamber for the BBs to seat into.  It might be a ritual observance, but it did sort a feed problem on my MP5K with a less than brilliant hop chamber.

 

[steverebo]

When BBs do shoot, how's the hop on them?  I'm wondering if they're just not making it past the hop rubber - and I have read the thread, and am looking at the barrel as the culprit.

If it's a feeding problem, I've had some luck with hand-drilling a very slight detent into the top of the hop chamber.  6mm drill bit straight up the feed tube, a couple of turns by hand, just enough to create a tiny dome at the top of the chamber for the BBs to seat into.  It might be a ritual observance, but it did sort a feed problem on my MP5K with a less than brilliant hop chamber.

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Yeah I grabbed it from ak2m4 I think I've been his no.1 customer over the past months spent about £200 on barrel gearbox parts ect.

He is the only one with the maple leaf barrel in stock at 310mm if I grab one today maybe I can get it by Friday fingers crossed.

I have done a bit more research and some people are only able to use the ZCI hop rubber with zci barrels without issue and I'm using a maple leaf 60 o do have a few zci hop rubbers floating around at home that came with my zci hop chamber and barrel so nay give them a go it might just be the hop rubber giving me issues 

 

[concretesnail]

If its from ak2m4 then its worth asking.

I'd still look at the mag spring for the mags which have an issue as you already said all the other midcaps feed and fire fine and that uts just the 200rnd ones that don't.

I seem to recall people that have the large midcap pts mags having similar issues, just too much pressure.

I know I have zci barrels and maple leaf rubbers in nearly all my rifs and use nothing but mid and low cap mags.

 

[steverebo]

If its from ak2m4 then its worth asking.

I'd still look at the mag spring for the mags which have an issue as you already said all the other midcaps feed and fire fine and that uts just the 200rnd ones that don't.

I seem to recall people that have the large midcap pts mags having similar issues, just too much pressure.

I know I have zci barrels and maple leaf rubbers in nearly all my rifs and use nothing but mid and low cap mags.

Click to shrink...

So cutting some coils on the mag springs helps?

 

[RostokMcSpoons]

I was interested in the same mags so watched a few reviews etc.   I think the advice I absorbed was to run the mags at 120 rounds until they'd really settled in, before trying to squeeze them to full capacity.

No idea if that's any use in your case though

 

[ak2m4]

As others have said, do the drop test, check for burrs etc, if there is an issue drop it back to me and I can test / replace, it's no bother.  Maple Leaf rubbers design is quite a bit different from the old / standard one, longer lips 1.8mm and a much wider aperture - can cause all sorts of problems.  If you have an old standard bucking laying around try that.  It just might be the combination of all the parts that just stops it's from feeding.

It's a SA Edge, with the blue rotary chamber right? 

 

[steverebo]

As others have said, do the drop test, check for burrs etc, if there is an issue drop it back to me and I can test / replace, it's no bother.  Maple Leaf rubbers design is quite a bit different from the old / standard one, longer lips 1.8mm and a much wider aperture - can cause all sorts of problems.  If you have an old standard bucking laying around try that.

It's a SA Edge, with the blue rotary chamber right? 

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Yep so in pursuit of getting this solved I have:

swapped for zci plastic hop chamber

Replaced the piston head to a rocket double oring

Replaced the nozzle to a rocket double oring and sanded a tiny tiny amount off the top to match the original nozzle height.

Tried the MR Hop rubber and standard maple leaf 60

Still had the same issue with inconsistent dry firing and eventually a jam.

I have now ordered a new Chinese tappet spring zci tapped plate and a shorter zci nozzle to see if swapping these helps

I spend £90 on the mags and when I explained the issue the return was rejected based on them staying it was my gun not the mags with the issue so I've got £90 of useless mags unless I identify the problem

I do have a couple of the zci hop rubbers that you supplied with the barrel and the hop chamber so when I get home I will get one of these installed I see how it goes.

I will also fill the mags as much as physically possible and leave them till Saturday when my next game is and see of that helps

 

[ak2m4]

@steverebo hmmmm try the original hop chamber instead of the ZCI rotary, and try the ZCI rubber as well in both as well.  If you have a ML inner barrel to hand it's worth also trying that.  Can always post one out to you tomorrow (should arrive by Friday) as long as I get it off in the early post.