Steyr AUG FAQ and Helpdesk

[Mike Obrien]

the slot spacing and the area under the "lobes" is the issue. ALSO just so you all know the JJ airsoft METAL nozzle is SLIGHTLY smaller then the JG nozzle, BUT it has an o-ring. The O-ring made a near perfect seal where as my JG one leaked past the cylinder head. But the JJ nozzle leaked past the bucking, where the JG made a perfect seal against the bucking. the exchange literally made no difference in my FPS, it just moved my leak to a new spot. So.... any good long O-ringed nozzles?

Another thing, anyone know a good cyl/cylhead/piston head combo that gives a really good airseal?

[DarkLite]

I've had good experiences with Guarder compression parts.

[Mike Obrien]

Good to know, looking at a 323-330 fps variation... little high for my taste... but with my flat hop mod I hit a consistent 200 feet, with .30s I might add. Stock JG cyl head, gears, piston, piston head, and motor. Still cant find a way around this rail issue though...

[Mike Obrien]

So I managed to get my hands on one of those full metal hop units hedganian rages about and says is the best there is. Maybe for a CA, but not for a JG or TM. Upon install on both of my JG and on my TM AUG the FPS and feeding suffered tremendously. It barely fed, and when it did fps ranged from 165 to 280 when prior with the plastic unit a consistent 323-330. It was a CA AUG that it came out of, and it worked very well in that rifle.

 

BUT the hop arm is perfect. The plastic units, and the JJairsoft units hop up arm has a channel that is far to recessed, so hop engagement is poor. The PDC arms recess is much shallower, and thus has much better engagement, MUCH more suitable for a flat hop mod. You could always try to do an M-nub style with the original hop arm, but then it requires modifications that are irreversible.

[Mike Obrien]

Very annoying I can't just edit my posts and just add this in instead of putting yet another post.... So I am still having the rail issue, I widened the spaces between each rail block and my EOTech still wont sit right to mount it. Does anyone know of a aftermarket picatinny rail I can buy that will fit the rail? Rail is roughly 8 inches long. Think I can just grab any 8" picatinny rail then just drill holes to match the gun's receiver, or is there a specifically made rail I can buy?

[Hedganian]

The stock rail on the AUG has little... projections under the rail which get in the way of some types of scope. You can dremel them away - they don't seem to be there for any useful purpose - and then you'll have no hassle mounting your optics. I'm afraid I don't have a good picture showing it, but hopefully you'll be able to figure out what I mean.

[imprzaWRC]

So, got my JG AU3G earlier this month. Have been doing some mini DIY mods to it and testing the progress (R-Hop+M-Nub, barrel spacer with masking tape and teflon tape through out the inner barrel, teflon taped bucking, teflon taped hop up dial and its lock). While I did managed to cut half the size of grouping down, I'm having weird issue with zeroing my scope on it though. Every single time I separate the upper and lower, I have to re-zero the scope. Meaning: after reassembling the upper and lower without any mods done, the grouping of the shots would just go to the left (or to the right) of the crosshair (already centered the shots before the disassembly). Just wondering if this is pretty common with AUG or it's just my own problem (probably been doing something and I didn't realize what it is).

 

Sent from my GT-N5100

[Mike Obrien]

Hm, not normally that doesn't happen... sounds to me every time you put it together you shift something. Something is loose some where. I know that the teflon/masking tape method isn't full proof, and is entirely possible every time you reassemble you apply different pressure to the tape and it moves the barrel just a bit. A better alternative to tape would be soda cans.

 

Also: how is your R-hop+M-nub? did you use the stock unit? what FPS what BB weight?

[imprzaWRC]

Thanks. I'll see if I can do a better mod for shimming the dial.

 

I haven't had a chance to do long range testing yet, so I don't really know how it performs right now. It is better than the stock but its groupings is still around 7 inches at 13 yards. I'm using EXCEL bb 0,25 grams. Chronos at 357 fps average with high at 364 fps and low at 348 fps (which is equivalent to about 390 fps with 0,2 grams). It's giving me 10 rps (stock JG battery). I also compared the grouping with 0,36 grams Madbull bb. At about 13 yards, the left-right grouping is almost the same. The up-down grouping is tighter with 0,36 grams though (guessing the higher weight bbs resulting in a more consistent fps). I am suspecting that the nub that I made is also not long enough. I am just placing m-nub in the space of the original nub for now. I plan to mod the hop up arm to something that enables me to put a longer nub space later.

 

At the moment, I think it should be able to shoot further, but I will be loosing my first shots because I'd need to trace the bb everytime. My plan is to get it to shoot at most around 2 inch grouping at 13 yards for now.

 

Next set of mods will be trying to cut down the fps variation (gearbox and nozzle mods). Any tips/tricks/pictorial guide is appreciated.

 

Sent from my GT-N5100

[Hedganian]

Taking the weapon apart will affect the zero. There is no way around this. It's true with real-steel and it's true with airsoft. You can minimise it, but never eliminate it completely.

 

The answer is to take it apart as little as possible, re-zeroing every time; or to just stop worrying so much - this is airsoft. Firstly, the BBs aren't that accurate anyway; and secondly, you only need to be able to hit a person at reasonable range, not drive nails.

[imprzaWRC]

Update: Haven't properly set the hop up. Confirmed to shoot 40 meters but the grouping is still very messy (will test on the next game for longer range). Just printed out my draft outer barrel to RIS spacer. No more wobbling outer barrel. Will see next week if that actually improves accuracy.

[imprzaWRC]

Sorry, I can't edit my last post because I can't seem to find the edit button. Anyways, just wanted to share that at 12.1 meters the outer-barrel to RIS spacer actually did NOT improve accuracy at all. I'm having problems zeroing my scope. Will try a different scope next time. But at least, the paper target shows what kind of groupings I'm currently getting (more concern on the width of the grouping, both shows about 4 centimeters width). Will see if it makes any difference at longer range (I doubt it would although the up-down grouping seems to be 1 cm tighter on the one with the spacer).

 

Prior to addition of outer barrel to RIS spacer

 

After the addition of outer barrel to RIS spacer

[Mike Obrien]

Interesting, what is that spacer 3d printed? And there was no improvement at all? What type of barrel and bore? Also though you may have corrected barrel wobble in the front but you can get movement back at the hop unit to, see if it is loose or anything. That is what a 4 inch grouping at around... 40 feet? Not sure if I am doing my math right. That isn't terrible, you must remember we are dealing with smooth bore guns. How is FPS consistency?

 

 

Also just noticed your little mod list, I've never heard of shimming the hop up unit, nor Teflon taping it, unless you mean around the bucking. Though that R-hop... I would move your BB weight up for one, if it is a GOOD install you should be using AT LEAST .30s, I use bioshots, don't know excel, can't say if they are good. Your grouping will get tighter and you will probably increase range once the hop up is properly adjusted and you up the BB weight, R-hops don't like light BB's.

 

Also the R-hop bucking, make sure the mound and locating bar are sanded away nice and smooth and the bucking is at a nice 90 degrees. (I found prome soft type worked great)

 

Also at 320-330 fps with .30s on a good R-hop expect about 200 feet.

 

If not sure how to attain that FPS on my JG I had a prome 120 spring, metal ball bearing spring guide, full seal cyl, stock gears, motor, nozzle and was right in that window hop adjusted. Any excess FPS variation (Less the better, but don't allow more then 10) you will have to find your leak(s), tape it if you can, if not guarder parts have sealed nicely for me in the past.

 

Oh and just for trial and error, being I noticed your barrel ends right at the 14mm threads, try shooting it with and without the suppressor, the BB could be just tipping the suppressor at the end throwing off its spin, if that's the case either lose the suppressor or get a longer inner barrel.

[Baddbaz]

Could be barrel resonance . I spent a lot of time and effort packing my barrel down its full length to minimise this as much as possible , the Augs suffer realy badly with it . Plays havoc with groupings . My mad bull was terrible for it , changed to a Lonex / first factory barrel and most of it vanished . I call it tuning fork syndrome nowadays ,,

[imprzaWRC]

Hi, sorry I couldn't reply any of this sooner.

 

@MikeObrien: The spacer is 3D printed. I've put it up in shapeways ( http://www.shapeways.com/model/1945917/jg-au3g-outerbarrel-ris-spacer.html ) if you want to see what it looks like (friction fitting). The only upgrades I've done to my AUG is listed in the paper (which means, aside from R-Hop, everything else is either add-on DIY or stock JG). I've only toyed with the upper receiver and haven't started any fixes to compression mods (I'm still gathering tools required for the upgrades, which is mostly DIY upgrades). My other rifle is an Ares boltie that's been upgraded and confirmed to be good up to 60 meters with A4 paper sized grouping (haven't double check longer range). So, I'd like to say that I'm not totally blind with accuracy/grouping upgrades (although I probably still am), I'm going with incremental upgrades, which usually means that if I change one thing, I will check to see if the grouping becomes tighter or not. So, I'm a little bit surprised that the outer barrel lock down hasn't yielded better results (I've tightly packed the inbar to the outbar).

 

The outer barrel spacer is long enough that when the upper is not yet connected, there's less than 0,5 mm gap for the the other end (hop up) to move. I think that this is already much better than without it, but I could be wrong. I'll try and wrap the back of the outbar a bit more and see if I can reduce that gap even further and see if that will increase the accuracy.

 

The shimming that I meant is for the hop up dial and hop up dial lock. In my JG, there's about 1 mm gap between the dial and the hop up body. So, it's really wobbly. I find that due to this gap, the AUG can't maintain it's hop up setting in between shots. That's why I tried shimming the hop up dial.

 

As for BB weight, I have 0,36 grams MadBull bb that I normally use. But, so far, the testing hasn't shown any difference between 0,25 and 0,36 grams. I'm guessing I still need to work on the AUG further. I'll see about getting 0,3 grams bb and loosing the silencer for testing.

 

The rest of the AUG is stock JG, which means, there's a considerable amount of FPS variation (with 0,25 grams bb, they're up to 25 fps last I checked). I plan to get this down to +/- 2 fps (if I can make it).

 

@Baddbaz: I have read about barrel resonance before, but, in that instance they're using some thick packing to remove the resonance. The AUG has very little room between its inbar and outbar. Given that the resonance started from the piston head slamming the cylinder head and outward, the best thing to do is to remove the resonance from the inbar. As of right now, I'm only using 1 layer of paper masking tape + 2 layers of teflon tape. I'm not sure if I can do more than this (no budget to get proper inbar, wife's pretty damn strick). Or is there a proper DIY link you can share?

 

Update: I forgot to test my R-Hop settings for longer range again (forgot about it somewhere between frustration of loose grouping and wanting to use my boltie to avenge the earlier lost).

[Baddbaz]

I have used rubber wrap to pack my barrel as tightly as poss , it is a rubberised self galvanising plumbers repair tape , also there are two thicknesses of ptfe tape . The thinner is for plumbing use and the thicker variant for gas fitting / sealing .. The fit is very tight between some parts if the inners and outers . Copious use of silicone greAse is the answer to sliding it all together . Am experimenting at the moment with wrapping the gearbox in rubber wrap as it is airtight and padded enough to reduce resonance . Will post up once I get the gun back together and tested .

[Mike Obrien]

A misadjusted R-hop whether it be poorly installed, to light a BB, whatever it may be, it will affect your grouping, and greatly range. The AUG hop up unit no matter what version, is difficult to get a R-hop well installed. Though right off the bat I can tell you a large issue is your FPS variation. R-hop is sensitive to that, anymore then 10 and it can get really inconsistent. Talk to Hunterseeker directly and he will say 10 is even to much, but I found I can get good results still. By the way what barrel did you put the R-hop on? I hope a prome 6.03, they seem to accept them the best and are very snug in the AUG barrel.

If your AUG is mostly stock with .30s you should probably be in the 280-290 window, I do know someone who uses an AKS-74 with a R-hop at that FPS and gets 160 feet easy, grouping is within a torso sized target.

[Jibbity]

@Mike Obrien. A properly installed R-Hop will work with any weight BB,  quality heavier ammo just has better accuracy potential at range. I have used mine with 0.20g and 0.12g extensively in CQB.

 

R-Hops are also not any more sensitive to FPS variation than any other hop method. Good air seal is typically the first step in consistency.

 

The only AUG hop specific issue I had with the R-Hop is cutting the thickness of the M-nub down (Evenly) to work with the hop arm.The install in the barrel is the same for everything unless you are getting into the ER-hop, in which case you need to consider if your hop unit will be able to provide even pressure to the extended patch.

[DamnLion]

Speaking of 3D printed items, anyone interested in an AUG rail adaptor for the A1, A2? Or other custom bits I suppose.

http://imgur.com/vKaptnn

I also have the CAD files for any length barrel / the stock AUG flashhider if anyone is interested.

Long live the AUG   

[3vi1-D4n]

Wow that 12m spread is terrible for an AEG, and my GBBRs have half/third as much spread as that.   The fluctuations in FPS you should be able to see the variation of Hop up trajectories which may be causing this vertical spread.  Otherwise its the barrel warp caused by a number of things which is causing your vertical spread.

 

Its a bit hard to help determine the issue without the gun in hand and having done the tuning and hop up by myself.

 

It may be sucking eggs for you, but this what I do as soon as I get the gun out of the box to minimise/eliminate all sources of inaccuracy systematically:

 

- Open it up, strip it down from outer to inner barrel, and mechbox.

 

Mechbox side:

- Clean the mech but keep some fresh grease on the gears.

- Degrease the cylinder and piston, and find a piston O-ring which fits exactly to the cylinder, which means you don't need extra grease.  Grease and oil affects accuracy

- Ensure good airseal of piston and cylinder, change O-ring if there isn't good airseal.  The O-ring should seal air when compressed against blocked cylinder nozzle, but should slide down freely under its on weight against gravity

- Ensure good airseal of piston/cylinder to airnozzle. If leaky, add super glue to thicken inside of the airnozzle for airseal, and ensure free movement

- AOE adjustment/modification

- Semi-auto cuttoff modification to ensure trigger block does not wear or jam on semi-auto

- Shimming, w/o then with motor etc.

- Note the spring tension and expected FPS

-- If everything passes the tests, then Reassemble

 

Barrel side:

 

- Degrease the whole inner barrel, inside of the outer barrel, the hop rubber, the hop unit (I use detergent on plastic/rubber parts).

- Check inner barrel straightness (use the Concentric rings test), if not straight then ditch barrel

- Fit inner barrel into outer barrel and test straightness, if not straight then figure out how to modify the section of the outer barrel which is causing the issue

- Fit Hop unit + teflon mod the hop rubber for airseal

- Fit barrel/hop unit to outer barrel

- Check Hop unit level alignment is parallel to horizontal plane

- Note any movement in the barrel assembly and try to eliminate/minimise it without causing inner barrel to bend.

-- If everything passes the tests, then Reassemble .  If not then parts will need to be modified to fit.

 

Fit everything back and reassemble.  This is a whole system test.

 

- Fire an empty round on semi-auto, shine a torch into the breech while the barrel assembly is inside the gun, and check barrel straightness from the muzzle.  If the receiver is exerting pressure on the outer/inner barrel then chances are it will not be straight, then analyse, disassemble, and modify to relieve the pressure point or misalignment

- Test FPS with hop off, it should correspond to the FPS of the spring tension, if not then disassemble and find source of air leak

- Test for FPS fluctuations.

 

Once you are happy with that then you can start looking at the accuracy.  At this point you know mechbox is tuned, barrel structures are supporting the barrel correctly and the only issue is the inner barrel, hop and hop rubber.

 

So:

 

- Note down sight to bore distance.

- Set up a target at 5m, draw a target dot and draw downwards the distance of the sight to bore.  This is where your rounds will be expected to fall

- With no hop, zero the gun to the point where your rounds are expected to fall, given you are aiming for the target dot

- Once that is done, aim at 50m and adjust hop up until BBs are flying flat towards that point.

- Note down the wind direction and any strange veering, erratic hop up, ineffective hop up, or unability for BBs to float.  This is due to the hop rubber/hop nub combination, change rubber.

- Once hop rubber is changed, retest FPS and readjust hop.

 

-- Once you are happy, do a final check and adjust your sights vertical adjustment to point of aim at the distance you want to zero at. 

 

+ Depending on the hop profile and barrel length you can do a single point of aim zero or a double point of aim zero. 

- For short barrel guns I do a double point zero so I hit dead on at 30m and dead on at 60m, while shooting high from 30-60m.  This is because the hop doesn't float the BB as well on short barrels.

- For long barrel guns I do a single point zero.

 

 

Only then you should do an accuracy test. 

 

At this point the only thing affecting accuracy is things like barrel whip and other mechanical/structural movements that you didn't detect when checking over the barrel assembly prior in the diagnostic process above.  From there then you can install your spacers and dampeners to see if it makes a difference.

[DamnLion]

On another note, if anyone wants a true spec A3 upper (like me), I will 3D print them if someone provides proper dimensions.

[Jibbity]

@DamnLion. I would prefer that you just print the A3 rail and let people modify their existing uppers. That way you avoid the incompatibility issues with TM/JG/CA uppers. Cutting off the carryhandle/rail portion of the upper and drilling a couple of holes to attach the new rail should be easily accomplished, especially if you provide means to center the rail and locate the position for the holes.

[DamnLion]

@DamnLion. I would prefer that you just print the A3 rail and let people modify their existing uppers. That way you avoid the incompatibility issues with TM/JG/CA uppers. Cutting off the carryhandle/rail portion of the upper and drilling a couple of holes to attach the new rail should be easily accomplished, especially if you provide means to center the rail and locate the position for the holes.

Agreed - much easier on my end too, just unsure of the accuracy people want. Wondering now if an A3 adaptor could possibly bolt on to the A2 upper rail without being too high..

 

Unfortunately, I have the A1 upper so I have no reference on hand. 

[Mike Obrien]

On a side note gentleman, anyone know a good place to get batteries for AUG? and what is the recommended lipo? I have a 9.6v 2300 right now, matrix battery. (amazingly a good battery even though it's a matrix) But I have been taking part in longer games and with the upgrades I have now a NiMH can't support it long term, so I need some good options.

[3vi1-D4n]

The battery size and type is dependent on your motor, your desired rof and your desired power output and role.

 

Bearing in mind the lower the voltage the less motor and contact erosion you will get and the gun will last a lot longer.

 

So it's getting the right motor will allow you to power good springs while maintaining good rof with a suitable gear ratio.

 

What I used to run on my aug was a systems magnum with an m125 spring outputting at 450fps. I wanted it as an accurate assault rifle on the border of a dmr and i ran the system on torque up bevel gear and a 7.4v 1800mah 20c outputting at around 14rps. It was so efficient that firing over 2k of rounds the rof did not decrease and didn't require recharge at all.

 

Hence the battery question is totally dependent on what motor you use in the gun.