[Cheekychaz0]

So i have a JG Aug and i have always wanted to make a sniper so I decided to try to create a DMR using it as a base as i like the look of the AUG. Internals are currently stock apart from a 7.4v lipo fitted. I need some advice on upgrades but i'm pretty tight for money so i'm only going to start out with some cheap mods.

I'm planning on:

Shimming the gearbox

Upgrading hop up rubber - Heard a few things about lonex bucking but
advice on brands would be useful.

Getting a full metal piston - Not sure if necessary but heard it is good to
have.

Noise dampening and teflon air sealing -like ones from guides such as the
holy grail etc.

Barrel modifications - I want to cut down the AUGs current insanely long
barrel to something more manageable also i want to
install a steel inner barrel. This will probably be 6.03.

Advice would be appreciated and if you recommend parts an idea of where to get them would be useful(I live in the UK so UK/reasonably priced international shipping would be good).

Many Thanks.

 

[1tonne]

What fps are you aiming for? Or does your club use joules? If so what?

 

[Cheekychaz0]

Preferably just below 450. It currently shoots just above 400

 

[1tonne]

Your best bet when making a DMR is to make it so that you can use heavier bb's with great success.
I would suggest an M140 spring and a 220mm x 6.01mm barrel. This should take it right up to about 450fps. (You may or may not need to clip one coil off). I would then use 0.36gm bb's. This setup should also make it quieter.

 

[Cheekychaz0]

Ok thanks will give it a go. Should i get a replacement hop up bucking and do flat hop as well or do that after?

 

[1tonne]

You can if you are finding that the standard bucking is not lifting the heavy bb's enough. Cheers

 

[Cheekychaz0]

Also when adding the 220mm inner barrel would it be ok to have it extend only half way down the outer barrel?

 

[1tonne]

It should be. 90% of the time they will be fine.

 

[Cheekychaz0]

ok and is 6.01 really needed 6.03 seems a bit more common and ive heard that sometimes theres not much of a diffrence

 

[1tonne]

Either will be fine. Some people feel that the 6.03mm has less jams.
I have only had a jam maybe once or twice with 5 years. Probably due to not cleaning.

 

[Cheekychaz0]

Ok thanks again for your help

 

[Cheekychaz0]

Oh and i forgot to ask why did you choose 220mm for the barrel

 

[1tonne]

Since you have a heaver bb, you will need more down pressure from the hopup and with a weak spring, the bb will not get past it. The shorter barrel means you need a slightly bigger spring to get it up to 450fps (on 0.2gm) as there is not so much time for the bb to accelerate. This bigger spring should give the heavy bb the kick to get it past the nub.
If you had a longer barrel you would have to use a weaker spring as the bb would have more time to accelerate and it would produce more fps. This weaker spring may not have the kick to get the heavy bb past the nub.
You may even want to try an M150 and if it is a little to high, you could just add a little weight to the piston.

 

[Stealthmaster14]

Depending on what year your AUG is, they generally have decent internals. Verify it has metal bushings (some come with bearings, those should be fine. Might be worth switching to metal bushings for peace of mind as I think JG usually have 7mm gearboxes)

Gears should hold some stronger springs okay, as long as they're shimmed properly.

Metal spring guide with bearings if it doesn't already have one.

Metal pistons aren't necessary in AEGs, in fact they're generally a bad idea.

I've been out of the Airsoft game for a while, but I think the JG pistons are generally fairly stout. I'd say run it until it strips, then something like this should work

Lonex Ultimate Upgrade M170 Polycarbonate Airsoft AEG Piston, Accessories & Parts, Internal Parts, Pistons, Polycarbonate Pistons - Evike.com Airsoft Superstore

I'd focus on getting a good air seal. Verify how the stock set up seals and plan on replacing the piston head, air nozzle (one with an o-ring), cylinder head, and maybe cylinder. Getting a great seal will help a lot with getting consistent shots. Replace whatever parts are the weak link.

Tightbore of some kind, madbulls are good for budget. Prometheus are one of the best if you don't mind spending a bit more.

Maple leaf makes AEG bucking and a nub, not sure how they shoot but they're the go to for bolt actions.

The JG motors can be extremely torquey, again depending on what year yours is. I would look into getting a 9.6v or using a 11.1v lipo so you have enough juice to pull back the springs. Replacing the plugs with deans will help trigger response a lot too, as well as overall battery life.

The biggest thing is going to make sure your shimming is solid. If it's off, the gears will not last long on an m140-m150 spring.

I wouldn't cut down the barrel too much, it'll help you get more fps so you can run a softer spring. I think around a 363mm barrel with an m130 should get you 450 pretty easily or close to it. 450 fps is doable with the right m120 with a perfect air seal. (depending on barrel length)

AUGs are pretty compact as is because of the bull pup design, might I ask why you want to cut it down since it's a DMR? CQB I get, but for outdoor play I personally don't see much of a reason to shorten it. But do you man.