WE AK-74U - was good, now bad

[ShelledPants]

Originally Posted by SuperHog

I am almost ready to pick one up but have a question regarding breaking.

Is it better to replace broken parts with orginal factory ones?

Is ra tech the best and only company making upgrade parts. Seems not a lot of choices.

There have been other companies producing parts for WE (TSC, Falcon... for instance), but RA Tech is the only one with consistant high quality parts.

[Brian McIlmoyle]

Upgrading

when going from stock parts to after market steel parts you need to consider what the parts interact with, Generally you should to a total replacement of all operating parts with upgraded parts to get your best results.

steel parts mixed in with stock "pot metal" parts is soon to result in failure of the softer parts.

[SuperHog]

That is a good point to remember when mixing steel and pot metal together.

[TPM001]

I agree with Brian. A gun is only as good as its weakest link. There's actually quite a bit of steel parts already in the stock AK which is great. Unfortunately, WE stopped halfway and left a very weak link in its system which is the pot metal trigger set. Fortunately RA-Tech has stepped in and stepped up on steel replacement parts.

The next weakest link is now the bolt carrier which is also pot metal. But the part appears to be well designed and beefy so I don't anticipate any cracking or snapping like what happened to my hammer. But I do expect the bolt carrier to wear down over time and the steel trigger set may actually accelerate that wear somewhat. So far, there doesn't appear to be any visible wear to the carrier after moderate use (unlike the stock M4 carrier which you would clearly see impact dents at the bottom of the carrier where it strikes the hammer after moderate use).

[TPM001]

Ok. RA-Tech steel trigger parts are now installed. Happy to report that the parts fit in nicely without any mods (phew!). The rear half of the trigger box (sear, trigger and inner select lever) was a piece of cake install. The front half was a bit tricky because there were a few parts that spilled out when i unscrewed the plate. Was a bit tricky figuring out the ultimate orientation and position of the spring that provides tension to the firing pin (the long side of the spring goes through the open slot in the middle of the firing pin with tension towards the rear of the trigger box, by the way). The rest of the parts (hammer and valve locker) were straightforward.

If you guys want to save a bit of money, you don't really need to replace inner select lever because this is a non-impact, low wear part.

Great quality parts from RA-Tech!

[-=ArchAngel=-]

Originally Posted by TPM001

Ok. I'm lovin the AK again now that I got another one. This time, I also bought the RA-Tech CNC steel trigger set. Quality of the parts look top notch. Will install on the weekend.

Like the WE M4 variants, the trigger box is easy to access. It's held in place at three points: one pin, the trigger handle and the fire selector. Removal of these items is a very simple matter and the trigger box containing the components easily slides out. It's a big box so easier to work with than the M4 trigger box.

Anyhow, I'll let you guys know how the upgrade goes but for now it looks very straight forward.

Oh, by the way, don't bother with WE's new rate of fire upgrade part. It's the yellow large brass looking part that slides into the rear of the steel body thus cutting the bolt travel essentially in half. I installed it on my first AK and it just causes more damage to the bolt carrier as it hits the part pretty hard, despite the spring loaded cushioning. I'd wait until someone comes out with an all steel bolt carrier first.


I'll also be modding the nozzle to install the NPAS. Hoping to get at least a 300 to 450 fps range by the time I'm done.

im not familiar with the design, but would putting something like felt on the bolt carrier help against the metal to metal contact?

[Andy n]

I am still waiting for my trigger parts to get in. So far I have fired about 500 rounds though mine and the stock trigger parts had help up but we all know that it is going to break sooner or later.

[TPM001]

After going thru 50 mags (approx. 1500 to 1600 rounds), the steel parts are holding up like a champ. It's actually working smoother now....so I guess there's a bit of a break in time. Bolt carrier doesn't appear to have any abnormal wear (other than superficial scratches). So far so good.

I also installed a side-mounted AK rail and threw on a C-More red-dot. Everything looks straight, centered, leveled and tight....so mil-spec is confirmed here.

All-in-all, with the Ra-Tech upgrade, this is turning out to be the best short AK on the market by far. Just need a steel carrier and it will be over-the-top (will probably be pricey, as thats a lot of metal). Now to install an NPAS and game this puppy on Sunday.

[TPM001]

My NPAS installation was successful. I can now get a low of 275 to a high of 425 fps on .20.

I had to mod the rear part of the nozzle by removing around 2.5mm off the raised tabs (pretty much cut them off but left about 0.5 mm on both sides). Also cut the rest of the base the same 2.5mm so that I maintain the same sized openings so that gas can flow to the carrier.

I think if you just went ahead and cut off the tabs entirely (and also remove at least 2.5mm off the base to maintain gas flow to the rear) you'll get closer to a max of 450 fps and a low of 300 or so.

I did this all with an exacto/box cutter knife. Pretty simple 5 min mod. Don't mod the spring.

Ready for battle!

[TPM001]

I've done 3 different NPAS mods to 3 separate AK nozzles and conclude that the maximum velocity I can attain is 430 fps. This is with the absolute maximum gas flow that the NPAS can offer in the ideal position within the nozzle. I haven't modified the spring. Has anyone else been able to materially exceed this? If so, can you tell me how you modded the nozzle? Ideally I'd like to up my max to 450 fps.

On the low end, I can get a stable 275 fps. I can actually get as low as 50 fps but it gets pretty random.

[coach]

Have you tried chrony'ing a heavier bb?

[Andy n]

I completely removed my tabs and the lowest I can get is 330fps with .20. I with what I am getting now I can get out door and indoor. I am waiting to get another bolt so I can just have 2 set and drop in when ever I go in or out.

[TPM001]

Originally Posted by coachster

Have you tried chrony'ing a heavier bb?

I chrono'd 375 to 380 with a .25.

[TPM001]

Originally Posted by Andy n

I completely removed my tabs and the lowest I can get is 330fps with .20. I with what I am getting now I can get out door and indoor. I am waiting to get another bolt so I can just have 2 set and drop in when ever I go in or out.

You should be able to get well below 330 fps. Did you cut out the ports that direct gas to the carrier?

[TPM001]

Just in case people are wondering, the short stroke attachment increases the rate of fire from around 8.5 rounds per second to 12 rounds per second as measured by my chrono device.

I think the 12 RPS is closer to the real steel rate of fire.