Should I sell my PTS Mega Arms MKM GBBR?

[Defender90]

Well I got my MKM back from Fire Support, at last, and immediately found the hop just was not working. Which was one of the things it went in for in the first place, to have the worn out rubber replaced. And it's still double feeding more than it used to (magazine feed lips?).

On top of which they advised me not to have it tuned down to legal game limits as it not be powerful enough to be reliable. (At the moment it's firing 407-360 fps on .20s at room temperature.) 

So it will never be playable and on top which, getting it back in my hands I remembered what a great long thing it is compared to my G&G Sig552. 

I still love the realism, the weight, all the Magpul dark earth external stuff I've popped on (which I heartily recommend), the ease of basic stripping, but the love has faded a bit. It's white elephant really, at least for me. I guess, also, I've fallen out of love with the AR15 platform a bit. (It's a Gucci M4 basically). 

Fair play, Fire Support warned me about GBBRs from the very beginning and tried to discourage me from buying! So I can't whine I that wasn't told or that they weren't honest and up front!

So should I just give up, flog it, it's 6 mags, bits and bobs, tools and various accessories?

Or is there another way to make it playable? It seems like HPA is not really welcomed at many sites which seems like the only way to make something like this viable that I've heard of.

Maybe the TM M4 MWS would be worth a go? Or is it more of the same? Bearing in mind the MKM's troublesome KWA hop adjuster and knock valve have been replaced already with Guarder steel parts so the MKM's weak spots have been much reduced.

Anyway I'd have to get the hop rubber fixed first, I won't get anything for it barely reaching 19 yards like this.

Here's my review of it, it's had a Magpul dark earth angled fore grip and a King Arms Front Folding Battle Sight (Dark Earth) on it since, (and the taclight and EoTech most certainly would not go with it) but apart from that it's the same.

PTS Mega MKM

 

[Davegolf]

Well I got my MKM back from Fire Support, at last, and immediately found the hop just was not working. Which was one of the things it went in for in the first place, to have the worn out rubber replaced. And it's still double feeding more than it used to (magazine feed lips?).

On top of which they advised me not to have it tuned down to legal game limits as it not be powerful enough to be reliable. (At the moment it's firing 407-360 fps on .20s at room temperature.) 

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If thats your FPS variation there's definitely an airseal issue there!

Its poor that they sent it back with the problem it went in for WTF?

So it will never be playable and on top which, getting it back in my hands I remembered what a great long thing it is compared to my G&G Sig552. 

Click to shrink...

Sig552s are pretty and very comfortable, plus G&Gs AEGs can be real nice, most of us run M4 only because they are best supported or people wanna be COD players!

Fair play, Fire Support warned me about GBBRs from the very beginning

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GBBRs are great, there's a lot of lame guns for sure that only have clack clack and Recoil appeal but GHK & TMs GBBRs are excellent.

Or is there another way to make it playable?

It seems like HPA is not really welcomed at many sites which seems like the only way to make something like this viable that I've heard of.

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I think HPA is fine these days, in a short space of one it has become much more widespread and common place, however power supply won't ever improve the hop problem, that needs addressing and personally I've never had as good a result with KWA style bucking as VSR type.

Maybe the TM M4 MWS would be worth a go?

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You wouldn't look back

 

[Wo1f]

I’m currently having the opposite problem. I’ve got a mega arms 308. The FPS is too low for a DMR 360 and the hop up.. well, there may as well not be one. 

I guy local to me is an is an aerospace engineer who does 3D printing in his spare time. He’s currently printing me a higher powered nozzle. He also has a hop up chamber that takes vsr barrels and buckings. What you could do is put in an NPAS or get a shorter or maybe wider bore barrel to drop the FPS. 

Is 407fps legal on an automatic weapon in the uk? I hate that retailers don’t drop power levels to legal limits for free. 

Link to hop chamber https://www.milspecsolutions.co.uk/specialist-suppliers/airsoft-engenuity.html/Airsoft-Engenuity-3D-KWA-LM4-Hop-Unit.html

 

[Davegolf]

400 auto isnt legal, i think the absolute legal limit is 370 isnt it?

Looks like the answer to all your woes right there if you can lock to semi for DMR or reduce to 350 for auto, oh and rekindle your love for the length!

 

[Wo1f]

400 auto isnt legal, i think the absolute legal limit is 370 isnt it?

Looks like the answer to all your woes right there if you can lock to semi for DMR or reduce to 350 for auto, oh and rekindle your love for the length!

Click to shrink...

I was under the impression that it was around 370 too. By that logic, it’s technically a section 5? 

If you got the hop chamber and dropped it to semi (you’ve only got 30 shots so I assume that’s all you run anyway) it could be a viable DMR. I have a sneaking suspicion that with a vsr type maple leaf bucking, your consistency will go up. They do a great job of holding onto the nozzle tip until the bolt is almost entirely to the rear. 

Forgot to mension. MWS master race.. its the way forward. 

 

[Defender90]

With the Guarder steel hop that was in it before it reached out to 30-40 yards, that got ripped by shattered BBs from double feeding, so that and a broken inner bolt spring was what I got it repaired for.

FS replaced with "APLUS Hop Rubber for "Pistol in System 7", which they tested and warned me that 1) GBBRs have a very small rate of hop adjust anyway. 2) It's a pure bastard to get the inner out and work on the hop (I can confirm), and that it takes hours of work - so this is not a money maker for them, nevertheless he is going to sort this out for me. They really did not design this inner barrel and hop unit to be worked on. He said that AHOP is a Guarder brand and that it should do the job.

I suspect the damn ball bearing came loose again, maybe vibration in the car, maybe when it was put down on the counter. Who knows?

Thing is, I have a System 7 pistol - a KWA H&K45 - it's awesome and shoots consistently out to 30 yards + with variation of about 40fps over the course of 20 rounds firing .25s on Power Up. Frankly the variation in fps was something I thought was intrinsic to GBBRs although the MKM's variation is a bit more than I was expecting (only got a chromo recently) it's not so different to the pistol.

As to legal limits, FS put the point that it won't be reliable at lower fps, the police still haven't been in an rush to kick down people's doors for the offence of owning a toy gun when you can buy air rifles which a much more powerful without any licence (rightfully so) and you'd struggle to describe those as lethal to anything larger than squirrel, and even that needs a headshot. So they really do have many better things to do and they're not retarded.

Truly though full auto is for short, infrequent bursts only and that in summer time. But I just like having it, like people with Range-Rovers who never take them off road or tow.

Yeah maybe I should flog it to someone who's got more skills with delicate mechanicals than I and go for a TM. It's just that I love the "bark" it has to it, the realistic internals and that lovely external body with sculpted looking upper and lower - it looks, and feels, so damn good! Where the TM is a just plain Jane M4. Yes I'm sad I know.

But I suspect that the MKM is 90% there, I also suspect that getting last 10% fixed will require a disproportionate amount of dosh chucked in the direction of a pro. But then you have to draw a line somewhere don't you.

Aargh so conflicted.

 

[Wo1f]

30 or 40 yards is dreadful. Especially at 400 FPS. The downfall of all KWA guns is their hop ups. A Tm mp7 will shoot 50m at 300 FPS. 

Fire-support seem to not have a clue about GBBR’s with statements like that. As much as I like them as a retailer (bought from them yesterday in fact) they wouldn’t be touching my gun. 

To give you an example of FPS variation, my TM mp7 and mws have a deviation over 15 shots of about 6 FPS. The nozzle needs to be stuck in the hop long enough for the B.B. to leave the barrel and the BCG to be at least half way back. Most consistency issues come from the nozzle returning with the BCG while it’s still trying to push gas out. 

As for the law, I’m just pointing it out. I’m fully aware seat aren’t going to kick your door down. I have a scar H I can turn to 500 FPS if I want. 

If you are set on keeping full auto, you will need an NPAS valve. That will let you control the FPS. That and the hop chamber with a vsr barrel and maple leaf bucking will fix your range issues and potentially your FPS deviance. 

Is the barrel that hard hard to take out? On my mega arms it’s a few little bolts to take the hand guard off and then the barrel nut. Where are you based?

 

[Defender90]

My HK45 seems to have excellent hop, I think KWA can be a bit "curate's egg" certainly the MKM came with hop adjuster and knock valve made of pure shite. And it previously shot  very nicely indeed with a Guarder hop.

In addition it does have a 6.02 tightbore as I mention in my review, so nearly all the weak spots have been eliminated from what was a pretty damn good airsoft to begin with.

In FS's defence they don't make any great claims to be GBB specialists and straight up say they know and prefer AEGs better.

I've heard of the AEG barrel and hop in the LM4/MKM platform, not sure if that is the same as the link you posted. Tbh it looks like a major pain to adjust that hop and I think the other one I heard of was adjusted with an allen key a hole drilled in the top of the outer. (Wish I could remember who it was told me about it and where I saw it).

The outer does come off reasonably easily (I have the barrel nut tool) but the inner and hop are just horrible, tried it once: Never again!

I'm in South Cambs.

An NPAS or something in that vein does seem to be the way to go...