jsmithski

or KWA LM4 cqb valve. Or cut the valve spring a bit. Or both (most likely only then you’ll get to 1J).

No matter what FPS you’ll have, use green autobot bucking if you’re going to have the fixed hop up, also pair it with a crazy jet inner barrel. Make sure you have spare nozzle, hammer spring and few nozzle springs.

One of the best additions is the maple leaf/ra tech hop up chamber and barrel. There are several upgrades available but seriously keep it stock and you’ll be happy. It is a great gun out of the box. Better spend the money on mags.

Most likely (99%) you put the lever arm in the wrong spot. I did that the first time.

There are many factors here. Do you have a good seal on the nozzle2bucking? What green gas are you using? I’m pushing over 2.6J using 380mm barrel, autobot bucking and KWA rocket valve in the nozzle.

@Bada Bing just noticed something on your SD3 video. You did not remove the rubber plug, with that part in, your lever does not work at all, so when you removed it completely you obviously did not notice any difference. Remove the rubber plug and then tell me if you feel stronger recoil or FPS increase.

Give me a quote. Is that a v1 or v2? Shipping to Poland. Another info from VFC (apparently they like me): “there is an oval rubber piece includes in V2 conversion kit, which is a locking piece to invalidates the ejector function, in most normal weather days which could saving the gas consuming” so when you insert it, the lever is always in the low position.

Maybe I’ll buy another one then

I’ve asked VFC, here’s what they said “will lock the valve knocker till bolt is ran enough distance to the backward, to make sure the gas output is enough the V2 ejector is redesigned for new magazine pressure” so it’s there to make sure there’s still gas going through when the bolt is traveling back. V2 lever is a bit longer, so it’s probably to make the recoil stronger

This is 100% true. Longer barrel gives more FPS but there’s no accuracy improvement. There is no single proof that says otherwise.

V1. To me it works the same with or without the lever but I did not do a proper comparison. Here they show a new version of the lever (longer on part close to firing pin), I’m not sure why this is needed, it keeps the firing pin from retracting apparently but the gun operates without it anyway. So what’s the benefit? edit: I think the purpose is to keep the release valve open a little longer (more gas = stronger recoil?). Normally the release valve closes when the bolt starts traveling back, with the lever on it will be open until the bolt engages the lever which is a bit later in the cycle. I will test that but I think by removing the lever I get better gas economy but slightly weaker recoil and FPS.

I’ll need to do some testing then, fill the mag just a bit twice and test with and without to see if there’s less gas used with the lever off. But it would also mean the recoil or FPS is lower without the lever. Interesting.

@Bada Bing do you know what the extractor lever does here? I removed it and see no difference in the operation of the gun except for the fact it does not scratch the bolt anymore.

Looks like the bucking in pinched. Try the new one without the C clip on it

This is weird, hi flow valve gives you more gas not less so recoil and FPS should increase unless there’s a leak somewhere. Swap the valve and test. Is it still the same, worse or better?

is it the same as in original TM mags? Swap it and check if possible.

most likely they have different gas release valves. Maybe modify them to push more gas.

I cut a buffer tube spacer from a 3/16 inch 70D Sorbothane to reduce the shock. To prevent it from getting ripped I’ve added a very thin shim on top of it. Seems to be a good shock/vibration absorbent.

to make sure you’re venting out air - press on the release valve when gassing them for about 5 seconds, then release and see if you can fill em.

What can go wrong with a fill gas valve? They are all the same, simple to fix if leaking. Here’s a pic.

The valve closes the nozzle at one point so no more gas goes to the inner barrel and all the volume left goes to the blow back. Some valves do not seal the nozzle 100% so when blow back kicks in still some gas leaks to the barrel which weakens the blow back and slows down the cycle a bit.

450 FPS with 370mm barrel.

So, anyone else tried installing the KWA rocket valve? Do you like the FPS vs recoil balance? I like how the rocket valve seals the nozzle - perfectly so no gas loss is observed.

There are few ways: 1. Get a valve with smaller ports. It’s the part that goes inside the nozzle (see pic attached). The smaller the holes and the lighter the valve, less gas will go through. If you buy a steel/aluminum valve it will increase your FPS. 2. Get a softer valve spring. The softer the spring the faster the valve closes the nozzle. You can achieve the same by cutting the original spring. 3. Make the nozzle gas exit hole smaller. There are many ways to do that. There was even a company selling so called magic inserts although there’s nothing magic about them, simply restricting gas flow. 4. Get a softer blowback spring. Softer spring will require less force=less gas to complete the blowback cycle. This has more to do with gas efficiency than the FPS output itself. Combined with other points can make a difference though. 5. Shorter barrel will always decrease FPS but if you won’t modify the gas output it will be greatly overvolumed and so joule creep will be enormous. I got a 180mm Crazy Jet barrel which gives now 1J on .2g but 1.4J on .43g.

I usually use Puff Dino 12kg or 14kg but I got 3 bolt sets modified for different FPS output. The one I use the most is shooting 350fps with 0.2g as this is the single auto cqb limit.