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jsmithski

Vfc Mp5 GBB

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There’s a lot of misinformation and false claims calling these bad ass replicas “the worst gbb ever created”. Especially now when they released v2, I think it’s time to give it another shot. Here’s my story...

 

I’ve bought vfc mp5a2 gbb in 2017 and haven’t use much mostly because I only had one mag and it had feeding issues. After some time looking at it hanging on the wall (and because I had few other gbbrs to play with) I’ve decided to make it skirmishable, that’s when I’ve come across nugentgl videos on y2b (long gone unfortunately). The issues vfc decided to skip during their QC (as usually) were easy to fix with aftermarket upgrade parts - this is the core of bad publicity, most of the reviews were made when those were not yet available on the market. I’m a gbb freak so I’ve bought almost all available upgrade parts... ended up with double the price of the gun itself plus I’ve added 4 mags to the set (worth noting the v2 mags fit v1 mp5 and even perform better than v1 mags). The ultimate skirmish ready vfc mp5 gbb part and mod list:

1. enhanced feeding ramp (crusader iirc) - fixes feeding and mag wobbling issues 

2. Hop up vsr mod - makes it shoot laser straight and greatly improves seal. I use maple leaf autobot bucking, omega nub and crazy jet barrel.

3. That’s all. Seriously no more. You can still put in all additional upgrades but they will not do much good. Steel firing pin makes sense. And removing ejector lever that keeps scratching the bolt. Let me know if you got one, I’m curious if you had same issues.

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8 hours ago, hitmanNo2 said:

What gas do you use?  They run pretty hot don't they?


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.

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On 23/02/2020 at 15:20, hitmanNo2 said:

Interesting.  What do you have to do to modify a bolt for 350 fps?


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.

 

 

5D01CC17-5F84-4690-8C8D-E484200AD2F3.jpeg

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@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.

 

 

29885E83-62F8-4385-B0A7-834A73A6CBB0.png

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1 hour ago, jsmithski said:

@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.

 

 

29885E83-62F8-4385-B0A7-834A73A6CBB0.png


I read somewhere that on the older gen VFC it worked as a gas cutoff lever. The V2 disabled this feature and it saved gas. 

Aside from that I never put much thought into it. 

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7 hours ago, Bada Bing said:


I read somewhere that on the older gen VFC it worked as a gas cutoff lever. The V2 disabled this feature and it saved gas. 

Aside from that I never put much thought into it. 


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.

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29 minutes ago, jsmithski said:


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.


Hmmm. Do you have the V1 or V2 SD?

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3 hours ago, Bada Bing said:


Hmmm. Do you have the V1 or V2 SD?


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.

 

 

1DAA7FD5-8DAE-4C52-9743-5637885951A0.jpeg

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11 hours ago, jsmithski said:


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.

 

 

1DAA7FD5-8DAE-4C52-9743-5637885951A0.jpeg


 

Righto 

 

I removed mine just to see and it works like normal. Although I haven’t tested the FPS

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8 hours ago, Bada Bing said:


 

Righto 

 

I removed mine just to see and it works like normal. Although I haven’t tested the FPS


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

 

 

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I’m surprised they got back to you.

To be fair to them they got their V2 system tuned to perfection. It’s sooo good. 

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2 hours ago, Bada Bing said:

I’m surprised they got back to you.

To be fair to them they got their V2 system tuned to perfection. It’s sooo good. 


Maybe I’ll buy another one then :)

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10 hours ago, jsmithski said:


Maybe I’ll buy another one then :)


I might be tempted to offload my SD3, just FYI 😉

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24 minutes ago, Bada Bing said:


I might be tempted to offload my SD3, just FYI 😉


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.

 

 

7D392E39-D821-4296-9BDC-92315816FFB5.jpeg

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@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.

 

 

001F85FB-9D4B-453D-9940-59031EC9BA2C.jpeg

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38 minutes ago, jsmithski said:

@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.

 

 

001F85FB-9D4B-453D-9940-59031EC9BA2C.jpeg


I disassembled the MP5 late last night and the rubber plug has disappeared into oblivion. It must be somewhere on my desk among my tools etc...

When I get time I’ll check the FPS and see how she runs. 
Yes, forgot to mention it’s the 2019 Version 2. 

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