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Time To Upgrade My Terrible Ak, How Do These Parts Check Out?


Sturm

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Hello!

So after finally making time to look at my APS/Javelin AK-74, I've decided to completely gut and upgrade and would appreciate any opinions or thoughts on the below;

Original problems: Weak Hopup Bucking, double feeding/bbs falling out barrel, shattered tappet plate, Seized gearbox (Linked to shattered tappet plate)

Literally no compression/resistance during hand & piston check, and probably a few other issues.

 

The barrel is 455mm and I don't know how decent the quality is, ideally I'd like to do a patch-job pass to get it ready for next month and then get higher end parts down the road.

I don't even want to talk about the cylinder/piston, so I'm flat out replacing them. I originally had a Bore-Up kit in my cart, but realized there's really no point with a 455mm barrel...

 

Here's what I have in my cart from Brill Armory right now:

Lonex Hop-Up Bucking (70 degree)

Lonex POM Ventilation Piston Head
SHS AK 7075 CNC Double O-ring Cylinder Head
Lonex Steel G3 / M16A2 / AK Cylinder
Guarder SP110 Spring

Guarder V3 Enhanced Tappet Plate (Ain't nobody got time for exploding tappets, should I use an SHS tappet for maximum compatibility?)

SHS 14.5-tooth Full Metal Rack Piston (Will I run into issues with stock gears?)
SHS AK O-ring Air Nozzle (Long version)
 
Sub-Total: $75.50, no barrel, Hop-Up unit, gears nor Motor. I suppose those can be obtained at a later date.
 
Picture of current scrap-monkey AK; soon to be transformed to heretical drum-fed (Semi-Custom) with bipod rpk-esque thing.
Yes, that's metal. Just covered in weird sand-paper grit stuff.
Gbh5fr5.jpg
 
Edited by ProPainTank
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Ok, so first off, an all metal tooth piston is not a good idea. Not for a 350fps gun that's running stock gears. Let me put it this way, the gearbox is designed to fail, and fail at a particular point. This point is the piston. Failure of the piston results in just that, and nothing else. The instant you remove that failure point, then it becomes a guess of what and where the failure point will be, and it could be on the gears, bearings, pinion, etc. Think of it this way, would you rather replace a $15-20 piston or a $40-100 gearset? A plastic toothed piston with the last 4-5 teeth metal will be fine. The only time an all metal rack is mandated is with very high fps builds that impose a lot of stress on the piston, and even then, they are overkill. Also, full metal rack pistons require absolutely perfect AOE otherwise kiss your gearbox goodbye. Even if the AOE is incorrect on a plastic toothed piston, many now days have oddly positioned first three teeth that allow the piston to self AOE with use.

 

Bore-up kits are good in theory but bad in practice. You are wise to avoid them. Once the O-ring wears out, it almost impossible to find a replacement. That and they are not as efficient on compression to begin with.

 

Scrap whatever piston O-ring you get with any of the parts. Go to your local auto-parts store and ask for a Kimball Midwest #14 O-ring. It will seal better and last much longer for compression than any you can get in airsoft.

 

A new wire job will go a LONG way for performance of your gun. But don't buy a kit, those are crap. What you really want is a good custom harness with %100 copper stranded 18 gauge wire to deans connectors. I can post up a how yo if you need help with wiring of the gun. You'll need 2' of both black and red/white wire which I suggest obtaining from a local ACE hardware.

 

Order a varying size set of shims as well. The shims that come in the gun are not correct, and you'll want some different more precise shims to properly re-shim the gearbox.

 

Only twice have I ever seen tappets break, so an enhanced one may be overkill, but that it your decision. I would chalk up the broken tappet to cheap JAV internals before anything else.

 

You'll probably find that, provided it isn't bent or dented, the new cylinder won't perform any better than the old. They are literally one in the same, but one is just more appeasing to the eye. You can save money by just utilizing the old one with new cylinder head. Again, personal preference for you though.

 

And as I said above, dean connectors will go a long way too. One of the best investments you can do for your gun and batteries. Purchase them bulk elsewhere though as "airsoft" ones from retailers are drastically overpriced.

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