VFC MP5 (Umarex Licensed)

[DrAlexanderTobacco]

I appreciate your taste in H&K, but Pizza2Night?! Seriously?

[3vi1-D4n]

The VSR mod doesn't work either on both the M4 and the MP5

 

Airseal is poor, loss of FPS, BBs rolling out the front.

 

I am sticking to the flat hop mod on the VFC hop rubber and the AEG nub, seems to get the best consistency out to 50m.  In the case of the M4 I use the Madbull blue bucking.  400fps for MP5 and 450fps for M4 CQBR.

 

 

I've spent hours & days trying to make the VSR hop mod actually work & it doesn't.

 

To start with it's fine but after a while BB's fall down the barrel when you fire the weapon & the next round chambered.

 

The only way I can make them keep ammo in the chamber is to keep the hop almost all the way on which gives you about 10 feet of travel before anything but a .43 goes directly into the air - I've tried it with really low power recoil springs (60% in some cases) & even shortening the nozzle, but they just keep pushing the ammo straight down the barrel.

 

That's five modified hop units, about nine different rubbers & buckings & at least 6 inner barrels, all types, vfc, AEG modded, WE pistol barrels modded. Waste of time.

 

My MP5K PDW however likes them, again, needs the hop on really high (which pushes ammo to the right unless it's .43g) but at least it goes.

 

I do all the power downgrades myself, it's just so easy.

 

Take out flute/floating valve

add a piece of aluminium pipe inside the valve & glue in place.

if power is still to high, add a lesser diameter pipe inside that. 

 

I've found that the gas mags running on guarder black gas (large can) & full steel hammer, strut, valve knocker & 130% hammer springs give you zero cool-down almost & after the power downgrade 337fps average.

 

I'll do a video later.

 

AP.

Edited April 15, 2014 by 3vi1-D4n

[Armourpiercing]

That's what I was talking about.

I can't imagine I've got it wrong a dozen times, I'm not trying to blow my own horn, but with my personal skills on gbb guns I can't see how its that great if I can't make it work.

AP.

Edited April 15, 2014 by Armourpiercing

[Tisane]

Obviously one of those things that works for some but not others then.

 

Done the mod to both my K and and my A3 and phenomenally improved the range and accuracy and that's with the hop just barely on and using .25s, not having any issues with either of them having BBs rolling down the barrel either.

They have both had around the 1000 rounds mark put down them since the mod was done so something may still crop up, but I've got 2 complete spare standard hop units just in case, saying that though given how utterly *suitcase* the standard hop setup was out of the box I would be inclined to work on finding the issue for as long as possible before reverting back to the standard setup.

[Armourpiercing]

So what's stopping your ammo just dropping down the barrel? 

 

What rubber are you using?

 

AP.

[Tisane]

I'm using

Maple leaf diamond 60 degree hop rubber

Maple leaf OHM hop tensioner

And

VFC Psalm inner barrels for both of mine.

 

One issue I've got though that you might be able to shed some light on for me.

Sometimes random but mostly on the first 2-3 shots, the blowback is very poor, after those 2-3 shots it returns to normal, but the occasional weak blowback will crop up.

Happens on both but more on the A3 than the K, the K has just about every upgrade possible from various different manufacturers, the A3 is standard with the exception of steel hammer, (also in the K) steel hammer shank, (also in the K) and copper cylinder (again in the K)

The only real commonality that I'm thinking that could be causing the issue is the flow/release valves in the magazines, and these are standard, but again because it's more or less random I'm still not 100% sure.

[Armourpiercing]

Thank you for that.

 

Are the mags completely full of gas &/or a bit warm?

Have you locked the charging handle back before you insert the mag?

 

Use a 130% hammer spring & the blowback problems tend to go away, if they don't then check the area where you hop adjust grub screw is - you may have broken ammo in there.

 

AP.

[Tisane]

Thank you for that.

 

Are the mags completely full of gas &/or a bit warm?

Have you locked the charging handle back before you insert the mag?

 

Use a 130% hammer spring & the blowback problems tend to go away, if they don't then check the area where you hop adjust grub screw is - you may have broken ammo in there.

 

AP.

Yep mags 100% full and room temp.

I do and I don't lock the charging handle back prior to inserting the mag but I will certainly give it a try locking it back every time and see what happens.

I did see you mention the 130% hammer spring but I haven't seen any anywhere, I'd appreciate a point in the right direction if you wouldn't mind.

And no bust BBs either, forgot to mention the Crusader feed ramps installed on both too, but the problem was present prior to installing them anyway.

[Studie]

You are doing it wrong then.

 

I've done many mods to the hop up system and the VSR10 done properly is the best.

 

However I'm not using maple leaf anything. I'm using the FALCON barrel + nineball gbb vsr-10 rubber purple + OHM rubber from maples.

HUGE increase in range when using .25g bb.

 

 

 

The VSR mod doesn't work either on both the M4 and the MP5

 

Airseal is poor, loss of FPS, BBs rolling out the front.

 

I am sticking to the flat hop mod on the VFC hop rubber and the AEG nub, seems to get the best consistency out to 50m.  In the case of the M4 I use the Madbull blue bucking.  400fps for MP5 and 450fps for M4 CQBR.

[3vi1-D4n]

You are doing it wrong then.

 

I've done many mods to the hop up system and the VSR10 done properly is the best.

 

However I'm not using maple leaf anything. I'm using the FALCON barrel + nineball gbb vsr-10 rubber purple + OHM rubber from maples.

HUGE increase in range when using .25g bb.

 

Define "properly"?  All it is is to chop off the head of the hop unit.

 

I tested using a Marui, WE, REAPs rubber all with the same result on the MP5, with and without the Ring to stabilise the hop rubber.

 

It needed heavy BBs, and while range is higher, FPS is lower even with BB weights kept consistent.  On examination the nozzle width is shorter than the hop rubber breech opening, the airseal is very poor.

Edited April 17, 2014 by 3vi1-D4n

[Studie]

Define "properly"?  All it is is to chop off the head of the hop unit.

 

I tested using a Marui, WE, REAPs rubber all with the same result on the MP5, with and without the Ring to stabilise the hop rubber.

 

It needed heavy BBs, and while range is higher, FPS is lower even with BB weights kept consistent.  On examination the nozzle width is shorter than the hop rubber breech opening, the airseal is very poor.

 

 

What nozzle are you using and are you using the OHM to press it down? Is the OHM hole filled in with a metal piece ensuring that the rubber is stiffer? 

 

Please take a picture and show us how you did the vsr10 mod.

[3vi1-D4n]

Will do when I get back from vacation!  Its Easter and I am jetting off to a beach on an Island

[Tisane]

See i haven't got anything in the OHMs hole and mine still works perfectly, infact when i did fill the hole with the little piece of rubber BBs jammed in the hop rubber even with it fully adjusted off.

 

We all do know too that there are two different types of hop arm on different MP5s, one is designed to have no nub and one is designed to have a nub under it, obviously you need the type of arm designed to use a nub under it.

 

Sent from my Lumia 920 using Tapatalk.

[Armourpiercing]

I've used the original units & arms, the after market for regular AEG - only one works and that's in the MP5K.

 

I've modified the arms to take different nubs, I've tried everything.

 

I get ammo straight down the barrel in about 5 different hop units unless its so far on it only flies .43's straight. So far it's toss.

 

The ones that did works stopped doing so very quickly.

AP

[Armourpiercing]

Oh, ehobby Asia had the 130% hammer springs.

AP.

[Tisane]

Cheers bud, they are out of stock of all strengths but I will keep an eye out for a restock and have a peek on other sites.

[Armourpiercing]

I split another hop rubber again this evening, I'm not going to continue along the route of vsr mods, it's - my range & accuracy was better with the standard set up. 

Total waste of time & money.

 

AP.

[Studie]

See i haven't got anything in the OHMs hole and mine still works perfectly, infact when i did fill the hole with the little piece of rubber BBs jammed in the hop rubber even with it fully adjusted off.

 

We all do know too that there are two different types of hop arm on different MP5s, one is designed to have no nub and one is designed to have a nub under it, obviously you need the type of arm designed to use a nub under it.

 

Sent from my Lumia 920 using Tapatalk.

 

Yup there is two types of hop up arms.

 

The one that comes on early version MP5 and the newer version that is designed to use a nub. 

 

BTW guys my MP5 project.blue is done!

 

[Armourpiercing]

Very nice! 

AP.

[Brigg]

Im also having some hopup problems with my Mp5 now. I had gotten one of the AEG bucking type hopup units and it worked great for a year or more but now I seem to be getting velocities of around 240 fps, consistantly. Ive checkled the nozzle assembly and FCG and I dont think the problem lies in those.

 

So its down to the hopup. Im just not sure what would be causing such a drop in fps.

[Armourpiercing]

You probably need to change the hop rubber.

AP.

[bankz5152]

That blue-ing looks stunning. I mean really stunning.

[Armourpiercing]

Ok, Finally success.

 

I needed to take the exposed end of the rubber, take a piece of pipe/metal ring, force it over the rubber & crush it tight.

 

Then I added PVC sealant inside the chamber end of the rubber. This seems to be holding the ammo in place after a couple of hundred rounds.

 

AP.

[Studie]

Thank you, very much! I tried to do my best. I am glad you guys like it 

[Tisane]

Ok so I fitted a harder hammer spring (not specific just random) to mine and hey presto, light striking and poor blowback have disappeared, however it has had the unwanted drawback of making the bloody thing fire full auto even in semi!!!

Removed the spring, think I shall put up with the 3-4 shots of poor blowback and keep my ability to use semi auto.