ASG Armalite M15A4 - does it have much potential? (+ hop unit question)

[pyromancer6]

Hi all,

 

Recently brought a friend's CYMA CM.009D back from the grave and had a blast fixing it up with a new board, gears etc to the point where it's shooting lovely which we've then sold for a really decent price (as in a good deal, we're not merchants 😅) to friend who's the entire reason we got into the sport in the first place so he finally has something 'competitive' to play with.



As payment for the tech work - I got to have his old ASG M4 and a bunch of other goodies which I'm more than happy with because it's always shot pretty lethargically and I was confident that I could do some work to it to make it a cheap little burner gun I can loan out to friends without worrying about the expensive and more unreliable pews breaking.

So, I chrono'd the thing and as he said - it's pretty lethargic and is shooting low power with it's very old hop system/design which would explain his frustrations with it.

 

So, I popped in a XT 380mm 6.00 tightbore in it, alongside a ZCI rotary with a ML macaron and already there's much better results.



This is great, it still sounds like a rusty sewing machine being pushed down a staircase mind but it's now up to power - with only one drawback that I can tell so far. The clearancing with the new hop unit is so tight that I can't move the hop dial by hand whatsoever and I have to instead use a tool to scrape it up or down, which while incredibly inconvienient also means that I've got doubts on whether or not it's playing nice with actually applying the hop.



Any ideas on clearancing the unit? I wouldn't know where to start filling so I thought I'd ask for advice.

Any more info on this thing would also be incredibly appreciated as searching the markings/model just leads me to various retailers advertising it with the same copy pasted description so I'm unsure on what size the bearings are etc. The pistol grip's adjustment screw also seems to be welded in place for some reason, so I guess a new pistol grip is a good idea?

Cheers!

Edited July 24 by pyromancer6

[pyromancer6]

Was meant to post in the AEG section. Oopsie doodles.

[Lozart]

It's a very old design so was never really intended for a rotary hop unit. You might have better luck with a decent quality traditional style hop unit as it's slimmer overall. Alternatively (with my engineering head on) you could try filing the adjuster ring down to a smaller size and cutting new knurls on it for grip.

[pyromancer6]

3 hours ago, Lozart said:

It's a very old design so was never really intended for a rotary hop unit. You might have better luck with a decent quality traditional style hop unit as it's slimmer overall. Alternatively (with my engineering head on) you could try filing the adjuster ring down to a smaller size and cutting new knurls on it for grip.

The one that came out of it is some sort of strange slim design 'rotary' unit rather than the water-mill looking one you're probably thinking of - I think I'll give it a go at sanding the wheel when I get time to see if I can get just a little more purchase on it. I don't mind the hop being fixed to a certain weight without a tool I just want to make sure it's applying it evenly on the arm.

[Lozart]

2 minutes ago, pyromancer6 said:

The one that came out of it is some sort of strange slim design 'rotary' unit rather than the water-mill looking one you're probably thinking of - I think I'll give it a go at sanding the wheel when I get time to see if I can get just a little more purchase on it. I don't mind the hop being fixed to a certain weight without a tool I just want to make sure it's applying it evenly on the arm.

 

As long as the receiver isn't impinging on the arm in any way it should be fine.

[pyromancer6]

7 minutes ago, Lozart said:

 

As long as the receiver isn't impinging on the arm in any way it should be fine.

Honestly - fixing the hop to 0.28s might be a good idea. Means that the type of people I'm going to loan this to (mates, work friends, relatives etc) can't accidently cock things up and have it shoot funny 😅

[Lozart]

24 minutes ago, pyromancer6 said:

Honestly - fixing the hop to 0.28s might be a good idea. Means that the type of people I'm going to loan this to (mates, work friends, relatives etc) can't accidently cock things up and have it shoot funny 😅

 

Amen to that!

[ak2m4]

The wheel on the ZCI rotary isn't the greatest design, so much so I'm looking to get my own one molded that's a little smaller and with better notches so you can at least count the turns etc.  As for your problem maybe take the upper off, turn upside-down, fit the rotary and barrel and try to see where the wheel is rubbing.  A customer did mention this before I remember and it was the gearbox case.

[pyromancer6]

3 minutes ago, ak2m4 said:

As for your problem maybe take the upper off, turn upside-down, fit the rotary and barrel and try to see where the wheel is rubbing.  A customer did mention this before I remember and it was the gearbox case.

Will give it a go over the weekend when I'm intending to crack on with this thing.
 

4 minutes ago, ak2m4 said:

The wheel on the ZCI rotary isn't the greatest design, so much so I'm looking to get my own one molded that's a little smaller and with better notches so you can at least count the turns etc.

This sounds fantastic, please do-tell if you ever get around to it so I can order like.. five 😅 (also big thank you for throwing in that ARL spring in my most recent order, completely slipped my mind!)

[The_Lord_Poncho]

14 hours ago, ak2m4 said:

The wheel on the ZCI rotary isn't the greatest design, so much so I'm looking to get my own one molded that's a little smaller and with better notches so you can at least count the turns etc.  As for your problem maybe take the upper off, turn upside-down, fit the rotary and barrel and try to see where the wheel is rubbing.  A customer did mention this before I remember and it was the gearbox case.

 

If you are looking for getting new wheels moulded (great idea!), might it potentially be worthwhile looking at getting some tighter fitting arms done too? On all my ZCI rotaries (and i have a lot!) there is rather a lot of sideways play/slop when the arm is in its channel on top of the unit. I recently invested in a few Delta Armouries 'beserker' hop up bundles - rubber, nub -  and an 'upgraded' arm - which fits the ZCI perfectly, and being a touch wider is a more snug fit on the unit with much less sideways play.

[ak2m4]

5 minutes ago, The_Lord_Poncho said:

If you are looking for getting new wheels moulded (great idea!), might it potentially be worthwhile looking at getting some tighter fitting arms done too?

Already ahead of you, I just didn't want to take the conversation away from the wheel issue.  I'm also looking at making a new POM rotary with slightly better tolerances

14 hours ago, pyromancer6 said:

also big thank you for throwing in that ARL spring in my most recent order, completely slipped my mind!

You're welcome

[pyromancer6]

Little update - Used a tool to get it shooting right with 0.28s and it's pretty much locked in place so there's no chance of accidental tweaking by curious workmates in the future lmao

Also decided to take the thing apart - these oldschool rifles are so much fucking easier to take apart it's unreal as the other two I've went inside [a DE UTR-45 and a CYMA CAR-15/M733] have had fancy bolt catch mechanisms, ambi selectors etc. The lack of functionality with regards to a catch etc makes things a lot easier.

With regards to the motor & grip - it seems that the 'high torque motor' that was mentioned actually is a ZCI HT, which feels pretty pokey and hard to move which is a good sign.



One problem, however - is that somebody's dearest (as it says DAD on the bottom of the grip) decided to superglue the motor adjustment screw in so it can't be moved at all 😅, so a new pistol grip or baseplate needs to be ordered.

One finaly question however - anybody know what size these bushings/bearings are? They're obviously smaller than 8mm but I haven't a set of calipers to hand and finding any technical info about this gun that isn't just a copypasted description about the joys of 'CQB Hi Cap Action!!!' from ASG's website 15 years ago is impossible. I'm guessing 6mm?



I'm pretty sure it's just a rebranded Classic Army gearbox in a plastic reciever so if anybody has more info I'm all ears. Cheers!

Edited July 30 by pyromancer6

[Lozart]

11 hours ago, pyromancer6 said:

Little update - Used a tool to get it shooting right with 0.28s and it's pretty much locked in place so there's no chance of accidental tweaking by curious workmates in the future lmao

Also decided to take the thing apart - these oldschool rifles are so much fucking easier to take apart it's unreal as the other two I've went inside [a DE UTR-45 and a CYMA CAR-15/M733] have had fancy bolt catch mechanisms, ambi selectors etc. The lack of functionality with regards to a catch etc makes things a lot easier.

With regards to the motor & grip - it seems that the 'high torque motor' that was mentioned actually is a ZCI HT, which feels pretty pokey and hard to move which is a good sign.



One problem, however - is that somebody's dearest (as it says DAD on the bottom of the grip) decided to superglue the motor adjustment screw in so it can't be moved at all 😅, so a new pistol grip or baseplate needs to be ordered.

One finaly question however - anybody know what size these bushings/bearings are? They're obviously smaller than 8mm but I haven't a set of calipers to hand and finding any technical info about this gun that isn't just a copypasted description about the joys of 'CQB Hi Cap Action!!!' from ASG's website 15 years ago is impossible. I'm guessing 6mm?



I'm pretty sure it's just a rebranded Classic Army gearbox in a plastic reciever so if anybody has more info I'm all ears. Cheers!

 

You can measure the hole with a ruler to get a decent indication. They look bigger than 6mm to me but still...

 

 

 

A quick google has revealed that the OEM is indeed Classic Army.

[ak2m4]

get some heat on the motor grip plate, that should dislodge the screw.  I'm guessing they're 7mm

[pyromancer6]

Relocating the motor wires to the rear of the grip has provided a much better sound - and while it's stilll screechy to my ears it'll do for this weekend's game as a loaner to a work friend who's interested in trying airsoft - appreciate all the replies! I'll take the thing apart over the week after the game to replace the gears with these 16:1 CYMA gears I have laying around and I'll try reshimming it a little quieter - it's a lot happier since changing the grip's wiring! - I'll even try ordering some fresh 7mm bearings to quiet the thing down since the XTs did such a good job with the 733 - appreciate it!