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renegadecow

GHK SIG SG 552 GBBR

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Somebody really needs to measure efficiency in terms of gas mass spent per average shot. People used to think the TM M4 was a gas hog because it ran out quickly only to realize not much gas was actually being inserted when filling due to the extra long fill valve.

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That interesting, but from a player point of view though, does that stat matter unless we're talking about green gas cost saving? All I'm concerned with is whether I can fill the mag "full" (full meaning whatever the optimal amount of gas, 4-5 seconds in the case of GHK), and being able to expand all the ammo the mag can take entirely worry-free, all year round. Because I feel like some platform might keep gas mass spending quite low at optimal temperature, but once that drops, it's not able to shut the rocket valve / push that bolt back the same speed it used to, resulting in drastic gas hogging when it's colder, there's so much variable for a comprehensive gas-off... 

Edited by blobface

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 KWA's light recoil still doesn't touch GHK on winter performance efficiency in the case of the AK, it's not like KWA is the most efficient due to its light recoil, it's not even close. 

Just gonna leave this here... -5ºC on ultrair 

 

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The SIG will probably get a VSR chamber later as all the other GHK rifles did.

As for gas efficency it depends on a lot of things. How large the magazines are, how long the the valve is open per bolt cycle, how hard it is to push down the hammer, how heavy the bolt is, nozzle's rocket valve, etc.

In my experience of cold weather effectiveness:

-GHK AK seem to work well to about 5 celsius on propane

-GHK AUG the lowest I used was around 10 celsius on propane where it worked fine(switched to CO2 since then)

-Marui MP7, HK45, PX4, 5-7 all worked fine on 0 celsius. The M&P9 suffered a bit probably because of its heavy hammer spring. Of course they were designed for weaker gas which helps in cold if you use GG/propane.

-WE SCAR-H worked ok on propane in 5 celsius but in the afternoon it started to simply release all gas. I assumed that the bolt/rocket valve froze.

-WE P90 with Icepick valve on propane in 5 celsius doesn't give a f*ck about the weather. I could full auto like it was 20+ celsius.

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My WE G36 worked perfectly fine in the winter, I never used full auto but I was getting through mags no problem. That's between 5 and 10 degrees Celsius now, our winters aren't too bad. 

Edited by AG1212

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Perhaps. I just figured the AK recoil setup is not best suited for full travel GBB but trunnion failure is probably a better reason.

 

Supposedly someone was coming out with a full travel kit for GHK. I wonder if it made it out and how it impacted things.

I'm going to emerge from the dead at this point, and say, yes, there was a full travel kit being developed, and it released a few months ago. I own a GHK AKM with one installed. It is awesome!

 

I can ask W&S if they have any interest in developing a full travel kit for this, if it turns out to really be short-stroked. The SG 552 irl does not travel as far back as an AK bolt carrier though (AKs travel over 10cm back, which is really a lot for an intermediate cartridge - partially due to the recoil rod and long stroke gas design).

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I own a GHK AKM with one installed. It is awesome!

I can ask W&S if they have any interest in developing a full travel kit for this, if it turns out to really be short-stroked.

Check the rear of the receiver and notice the growing bed of what looks like aluminum nail clippings. That's from the bolt carrier.

As for the SIG, the bolt doesn't travel as much as an AK of course, but it is still classified as having a long stroke system. What I meant was the charging handle should go through the rubber dust cover until a few mm from touching the rear most. With the GHK it stops moving at the start of the dust cover.

Edited by renegadecow

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So full stroke kit feasibility for the SIG would depend on the length of the guide rails for the bolt? Other than that, surely it would be straightforward to convert?

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I'm guessing the guide rails should be long enough as the bolt ought to be coming out from the back. The problem with their AK is the bolt comes out the top. Their guide rails were only designed to be as long as the original bolt travel needed to be so the full travel kit meant having the lugs going past the rails and getting shredded. But who knows, this thing is still in development. If enough people whine at them they might listen and make revisions for full travel.

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Wow that's impressive, my teammate had one and his was having real issue in UK winter and I ran my GHK AKS74U along it, and that's like 3c°, let alone -5. On ultraair as well? 

Your mate's gun might have had a leak. Most likely not a proper seal between the nozzle and bolt carrier. 

 

That's the thing. Efficiency really boils down to good seals. A minimal leak in that oring causes far greater gas consumption, which in turn causes far greater cool down for every shot, which again causes far greater gas consumption. That's what makes a gun inefficient. 

 

But every GBB is "efficient" as long as you keep the working seals in good order. "Gas consumption per shot" is not the same as efficiency.

 

Their guide rails were only designed to be as long as the original bolt travel needed to be so the full travel kit meant having the lugs going past the rails and getting shredded.

Really? In my understanding it was the other way around: they used AEG receivers that had short guides to prevent the classic boogieman of converting it to shoot real bullets, so they designed the GBB system to the short travel the guides allowed for. But I'm kind of allergic to AEGs, so never seen an LCT body to check that out.

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So full stroke kit feasibility for the SIG would depend on the length of the guide rails for the bolt? Other than that, surely it would be straightforward to convert?

Unless they use a similar system that WE did with the L85 (nozzle return springs). Then it would probably be more complicated. Technically the WE L85 can allow full travel (real SA80s stop a cm or two short of the charging handle disassembly slot), but it will lock up after a shot if the nozzle return springs (which also cut into and make quick work of the bolt carrier) are removed.

 

LCT is the OEM for a large amount (if not all) of the GHK AK series externals. I know there are significant differences between certain items though (such as fixed stocks, which are mounted completely differently than on AEGs). LCT obviously manufactured the GHK AKM stock (as its finish are practically identical), but it is not compatible with their AEGs (GHK AKs use a stock tang with two mounting points for securement, which is accurate for stamped steel AKs).

 

I think there are slight differences between the LCT and GHK receivers, although it is clear that LCT OEM'd them as well (I know that the Izhmash markings on the left end of the receiver on the GHK AKM are different than on the LCT AKM).

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Even with the full travel kit the BCG won't be able to actually go all the way back because it is longer than the real one(the WE is also longer but less so), probably to house the nozzle. Furthermore the tabs on the BCG which go into the rails are located too far in the back. Since the SIG's BCG is very similar to an AKs the GHK one will probably longer too. From the video in a moment the hop-up seems to be similar or the same as the AK or at the very least you adjust it in the same place.

The GHK AK bodies are made by LCT, probably was cheaper to make it like this and GHK didn't have the capacity/money to do their own. As far as I am aware the bodies are same as the AEG(they are longer than the real ones), only there are holes for the pins.

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Really? In my understanding it was the other way around: they used AEG receivers that had short guides to prevent the classic boogieman of converting it to shoot real bullets, so they designed the GBB system to the short travel the guides allowed for. But I'm kind of allergic to AEGs, so never seen an LCT body to check that out.

I don't think that would have been the reason. It would prevent converting it to fire in a long stroke configuration but any handgun caliber would work with short stroke. As for the AEG receivers, they're similar but aren't made from them. Maybe from the same blanks or tooling because there is more material on the GBBR receivers than AEG.

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It's not the obscure SG rifle I dream of some company ceo suddenly wanting made, but always liked the Sig rifles and happy the design getting some gbbr love.

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To add to the airsoft style early moaning, I really really hope they have transparent mag sleeves and enough clearance for stickers instead of keeping it black like they did with the AUG :( 

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