Aeg Inner Barrel Question

[SilentSparky]

Pretty new to the world of Airsoft and the tech side of things, but jumped on the DE M904 wagon and it's sounding pretty scratchy out of the box and not hopping well.

So thought maybe a split hop rubber and gearbox height needs attention.

I've not seen a great deal of inner barrels, but is this milling on the inside of the barrel meant to be there as I haven't seen it before? it looks deliberate, but it leaves a very thin piece of barrel where the hop rubber groove sits.

Thanks in advance for any pointers

View attachment 65340

View attachment 65342

 

[MadMole]

Something wrong there, never seen a depression there on any barrel before. Looks like BB's are injecting low and have worn an groove, or too much hop pushing them hard against that side

 

[SilentSparky]

Thanks, it's a new gun, only just come. Fired maybe 10-20 rounds through trying to set the hop and was getting wild results.

I'll contact the shop tomorrow, I assume just checking the barrel hasn't void any warranty, I haven't opened the gearbox or done anything else.

 

[Iceni]

I'd say that was a manufacturing defect. Looks like the mill they used has either selected the wrong program and picked up the wrong tool, Or more likely the tool/part has slipped in the mill. The fact it has a rotational grind pattern would also back that up.

You have 2 choices.

Send it back as defective, It should be accepted, And/Or ask the seller if they can send you an upgrade barrel instead.

Or just buy an upgrade barrel. AK2M4 have the steel ZCI 6.03 barrels and they don't cost the earth.
 

 

[SilentSparky]

Thanks, confirms my thoughts of "I haven't seen this before, but looks like it's been machined", just wanted to double check it wasn't some feature that I hadn't come across.

 

[Skara]

Don't tell Duck you had problems with it

but yeah, ZCI inner is the way to go.

If you crack open the box, post pictures so we can help!

 

[Adolf Hamster]

that's a new one, pretty sure it's a defect as i can't think of any reason why that would be intentional, it's gonna be letting all the air past the bb sitting in the chamber so no wonder the consistency is trash.

i'm with skara on this, a zci6.02 is a very good bang for buck option should sort that out a treat, while you're in there you could think about swapping rubbers if you're wanting to use heavier ammo (pdi W-hop or ml macaron/omega nub combo are my personal choices).

 

[Sitting Duck]

Not cracked mine open yet - I just bought for tinkering with over Chrimbo

Doesn't sound silky smooth, but looking to grind box upper to install 13:1's

(assume a SS sector with 13 teeth won't confuse the optical mosfet - but DSG is out the window)

so will reshim it with new gear set etc... when I crack her open

barrel is wanked for sure - the bb loads inline with bucking lips

can not figure out why that barrel was borked like that - don't make any sense

(the bucking lips would be centred, or should be, so why the ramp machined barrel like that ???

I'll assume the first batch of 904's were built with a bit more care on shimming

but like the FH's the first batch was Top Tech snappy builds assembled with TLC

Then the rest were just slapped together - so to speak

 

[SilentSparky]

So I received a response "The barrel is ok, they are designed that way." interesting, would also be interesting to see if anyone else's has this "design".

I have a spare stock CYMA barrel kicking around from a previous upgrade, so I'll throw that it for some testing.

But I'll order a ZCI barrel also, I have these in a couple of my other guns and they seem decent enough. I actually already have a hop rubber on route as I was planning on just swapping that out and running the stock barrel for a few CQB games.

UPDATE: nub had come out of place and was causing some hop issues, sorted that and reassembled with the barrel pictured above, putting out 340fps consistently and all seems ok.

Thanks for all the input, going to switch out the barrel regardless now.

 

[Stevobeavo]

Good to hear everything is working fine. Mines being delivered tomorrow ?

 

[SilentSparky]

Cool, seems good value, even with the niggles, compared to some brands, enjoy!

My gearbox/motor still sound a bit scratchy, so will be opening it up to check on things tomorrow ?

 

[Adolf Hamster]

i really don't get why they'd design that cut into the barrel?

it's an air leak, and looks like it'd put a pair of nice scratches in the bb on its way out too.

only thing is it'd keep the bb centred in the barrel, but why wouldn't they just use one of the myriad hop rubber designs that do that anyway?

 

[Paladin]

i really don't get why they'd design that cut into the barrel?

it's an air leak, and looks like it'd put a pair of nice scratches in the bb on its way out too.

According to the blurb ... And I' can't vouch for this since when I tried to by one, the length I needed was OoS ... 

The air channel along the bottom of the barrel provides additional and consistent back spin on the BB for the entire length of the barrel, rather than backspin just being applied at the hop-up, they say it provides better range and accuracy

Would be good to know if it indeed acts as expected/sold

 

[Adolf Hamster]

That isnt going down the whole length though?

Iirc there was a "wonder" barrel the yanks went crazy for that had a v groove in it to presumably let the bb rest and run straight.

In theory the gas blow-by around the bb *should* drop it rather than lift it as the flow is reversed compared to its intended direction flying through the air.

However if your using the right hop shape/compound, good ammo and a good quality barrel the results seem to be as good as you can reasonably expect from what boils down to a glorified musket.

 

[Skara]

Iirc there was a "wonder" barrel the yanks went crazy for that had a v groove in it to presumably let the bb rest and run straight.

it's the Magic Box Miracle Barrel, it has two grooves on the bottom at the hop end to align the bb with the rubber.

Given that I haven't heard nor read anything since its release back in 2016, it's safe to assume it was a flop.

 

[Adolf Hamster]

it's the Magic Box Miracle Barrel, it has two grooves on the bottom at the hop end to align the bb with the rubber.

Given that I haven't heard nor read anything since its release back in 2016, it's safe to assume it was a flop.

that sounds about right.

you can do the same thing with hop rubbers anyway.