KSC/KWA MP7

[Crimson]

No no no... You have got it all backwards.

 

As the liquid propane boils to get the pressure back up after your shot took some of the pressure out of the mag, the propane needs energy to make the physical change from liquid to gas.

This cools the liquid, and heat is absorbed from the magazine into the liquid.

If the magazine is cold, the process don't give enough energy to the liquid, and it will not boil. Thous the presure in the magazine is not rebuild, and your ROF and FPS go down.

 

Presure also depends on temperature so not only does the liquid to gas transformation go slower, the resulting pressure is also lower.

 

 

There for, your magazine needs to be able to absorb heat from something (the air) to keep going.

 

It is simple physics.

Most things in life is...

 

Wow i never thought about it like that

 

So then how do the lighter mags work for the WA series, i know from my mags that the cooldown is the same ?

 

In my WA m4 my wa mags weigh a lot, my boom arms weigh half, yet the cool down is exactly the same ?

[Duckling]

Wow i never thought about it like that

 

So then how do the lighter mags work for the WA series, i know from my mags that the cooldown is the same ?

 

In my WA m4 my wa mags weigh a lot, my boom arms weigh half, yet the cool down is exactly the same ?

 

Try to take the magazines apart.

A lot of the bigger gas magazines for guns like M700, have an outer shell, and then a smaller gas cylinder inside.

I have seen pix of aftermarked WA M4 magazines that were made the same way.

 

This solution is problematic. As there is no big contact area between the actual gas storage and the outer wall, in efect making the magazine a small insulated unit. Still air, is a quite effective thermal insulator.

 

KSC did the same withe the first generation TMP magazines.

They had a nice outer shell of stamped steel, and then an inner core containing the gas and BBS.

As they made the "HardKick" version, the magazine were changed til the ones stil used in the Mp9.

I had both, and the newer had more mass and all test we did showed that the old mag were more prone to cool-down.

Also the shell design were a lot slower to regain heat from the air.

 

For the M4 magazines, I would expect that the new ProWin (PGC) magazines are made from one piece of metal.

But as I don't have a GBB M4 (I dislike M4s... )

 

There are two thermal properties of the magazine material that is key.

How much energy it takes to heat a known mass of material a set number of degrees; Knowns as Thermal Capacity.

The thermal conductivity of the material, normally this follows the electrical conductivity.

 

A simple experiment.

Two of the best known good thermal conductors Al and Cu, have different mass/vol. ratios.

Al is light Cu is heavy. Taking even blocks of both in your hands, they would seem cold, as the good thermal conductivity would quickly move heat form the surface.

But as the Al block is after just a minute not cold to the touch as it have heated easy due to the low mass; The Cu block still feels cold, as it can absorb more heat, thus takes longer to heat up.

 

Reversing the experiment, submerging the blocks in 50C water for long enough for them to be evenly heated, take them out and place them on a table. After 5 minuts the Al block would have cooled to the air, as it have less heat stored, where the Cu block would still be warm as it started out with more stored heat.

Now, this experiment only shows that I'm right, If and only if, the thermal conductivity of the materials is approx the same. This can be tested by taking thin rods of both metals and put the ends into boiling water and hold the other end, the heat would spread fast in both materials, and by taking thin rods the difference in mass can be neglected. Try to do the same with a Fe rod, as this a poor thermal conductor.

 

The above experiments are involves no special equipment, and is only devices to let people feel the thermal effects withe there own hands. This require no math skills, but would enable anyone to understand the basics of Thermal capacity and conductivity.

Warning: Boiling water may cause damage to skin.

 

^ Duckling Sounds Like he Knows what hes talking about.

Still working on my degree, but I'm getting there.

Edited March 18, 2010 by Duckling

[3vi1-D4n]

The cool down effect/evapourisation of gas from liquid is related to ROF and FPS consistency, and is dependent on various factors.

 

1) Thermal propertiesof the magazine (mass, heat conductivity, surface area of magazine to surroundings).

 

The more mass the magazine, the more heat it stores, so the magazine cools down slower. But at the same time, the magazine has to gain energy from the surroundings, so a highly heat-conductive magazine casing material with a large external surface area is best.

 

But also the "drive" is also the temperature of the surrounds. The higher the temperature difference between the cool down mag and the surrounds the quicker the magazine/gas reabsorbs the energy (Newton's law of cooling/Fourier's Heat conduction)

 

There are two philosophies in the design, either create a very heavy magazine (as the case with AGM mags), or a light but thin magazine so it regains energy from the surroundings faster (as with WE magazines).

 

However WE has a casing around its magazine which limits the access to the air around the magazine hence limits the amount of available energy available. A double edged sword.

 

2) Internal area of evaporation. The speed of evaporation from liquid to gaseous propellant is determined by energy (speed of reabsorption) in the surroundings (see point 1), and the surface area of evaporation. KSC figured this out many years ago (WA still has to catch up), and built multi-layer evaporation "trays" or baffles into their TMP and M93R magazines. WE M4 mags also have these baffles.

 

FPS is determined by the pressure and volume of gas expelled and the impulse of gas release. The sharper the gas release, the quicker the BB accelerates. The more pressure the gas exerts on the BB in a short amount of time, the quicker the BB accelerates.

 

Hence a heavy hammer, plus a nozzle with an inner diameter closer to 6mm is best (i.e. WE M4s). But of course a heavy hammer will increase in the amount of gas released in order to push the hammer back.

 

Volume of gas released is dependent on weight of bolt, and strength of hammer spring, and the recoil spring. Heavier the bolt, stronger the hammer and recoil spring, more gas it uses, and hence more cool down the magazine experiences.

 

Rate of fire is dependent on weight of bolt, and strength of recoil spring.

 

FPS consistency is then affected by the energy in the gas (see the previous 2 points), volume of gas expelled per shot and rate of fire.

 

------------------------------------

 

The faster the ROF or the heavier the bolt/hammer spring/recoil spring, the more gas the magazine loses, so more gas is required to be evaporated and more energy required to reabsorb from surroundings.

 

On a well designed magazine, the energy reabsorbed by the magazine/gas may normalised quickly to surrounding level, so FPS may be kepted static. On a not so well designed magazine, then FPS may not be consistent (may drop high between first shot and next shot).

 

 

An ideal magazine would be made of casted heat conductive material (Casting metals have better heat conductivity than forged), have baffles, and have massive heat sinks off the side, but I doubt that would look cool.

 

Else we have a very light bolt, baffles inside the magazine (MP7) or heat fins outside the magazine (KJW M4). That will result in good gas efficiency, little cool down, consistent FPS but bugger all kick.

Edited March 18, 2010 by 3vi1-D4n

[kruck]

Spare parts arrived, fully working MP7 again

 

Going to give it a good skirmishing this weekend

[greg]

Spare parts arrived, fully working MP7 again

 

Going to give it a good skirmishing this weekend

Excelent, let us all know how you do.

 

 

Greg.

[kruck]

Fantastic performance all round, however...bad news.

After finally getting a sling that fitted the teeny tiny sling loops on the MP7, about 2hrs before the end of the day, I noticed my gun was moving a tad free from the sling:

Sling loop snapped off!

 

I tried it on the other side, 30 seconds later:

 

Going to have to get some RIS Sling mounts now!

[galactica]

get the FAB defense ones, I got three. they're excellent, and proper metal, not monkey business.

[Crimson]

oh man cant wait two weeks till i get my mp7

 

Heres what i ordered

 

6.01 edgi bull barrel for mp7 20cm long

NPAS unit

4 Long mags

KSC Taiwan version

Multicam Mp7 pouch (tripple)

 

What else should i be looking at ordering ?

[galactica]

RIS sling points!

[allizard]

We had this discussion before, but lets just take it one more time.

 

KSC is the Japanese design company, they emerged from the ashes from MGC of old.

They own a large part of the Taiwanese factory KWA.

 

KWA makes the guns.

The first ones made are made for the Japanese marked and labeled KSC Japan, they go to Japan and is marked with Japanese ASGK license number, and get a sticker saying "Made in Japan", but that is only the numer... the guns are made i Taiwan at KWA.

After the a few months most models are released for the general marked as KSC Taiwan.

KWA have there own lines of AEG's and are permitted sell the KSC designed guns as KWA to EU and US.

Normaly the KWA versions are without trades, or with the trades the stockist that orders them ask for.

Some times the KWA versions are also made in cheaper materials, as with the Glock series, where KSC guns have the heavy "cold" lower frame, as the KWA is just ABS plastic.

 

So, the KSC "Made in Japan" and the KWA "Made in Taiwan" is from the same factory.

That is why the tiny KSC logos, hidden on the true KSC guns, are never cast into the parts, but always engraved.

 

There are a few series of guns, like the TMP/Mp9 that never came in KWA versions.

I do not know the reason...

(BTW, the Mp9 is comming out in OD and FDE )

 

 

Umarex is just a german firm that only exists because they have a H&K license.

They don't produce anything, they just try to get other companys to pay them to get H&K models into europe.

There special licences Mp7 is just the KWA version, strangely with not all the true trades...

 

Duckling, one more time I have to correct you.

 

KSC DOES NOT OWN any part of the KWA factories in Taiwan. We are their OEM, that's all. On the other hand, KSC does have their own factory for models that we don't make for them.

 

KWA permitted to sell KSC guns when were sharing the cost of making the gun. (usually the molds). That WAS true many years ago. However, KSC engineers is NOW part of KWA and under OUR payroll!!! They transitioned to KWA in 2007. We design and own all new molds for NS2 model guns.

 

KSC MP9 not coming in US because KWA have our own MP9 using NS2 gas engine. KSC MP9 is still using Hardkick engine. I guess you haven't read our product announcement during Jan Shot Show 2010.

 

http://www.kwausa.com/forums/index.php?showtopic=2014

 

As for Umarex, I wouldn't call them existed only because of H&K license, they also have Walther licensed products plus a full line of Paintball and Air-gun products. They operates very much similar to ASG (Action Sports Gun) and Cybergun.

 

Some of KWA products also sold to ASG and does have trade marks through ASG. ex. 4.3 STI Night Hawk for the gas pistol, and LMT for the AEG.

Edited March 22, 2010 by allizard

[Crimson]

Do you have a link ?

 

Cheers

 

This is the only one i can find ?

 

http://www.wgcshop.com/wgc2008/main/produc...catid=&cat=

 

Edited March 22, 2010 by Crimson

[galactica]

nah, that's monkey rubbish.

 

http://www.israeli-weapons.com/store/rifle...ifle_slings.htm

 

at the bottom of the page.

[greg]

Do you have a link ?

 

Cheers

 

This is the only one i can find ?

 

http://www.wgcshop.com/wgc2008/main/produc...catid=&cat=

I've got that one & thus far it's been ok.

 

However, the one Galactica suggests, does indeed, make it look like monkey rubbish.

 

 

Greg.

[galactica]

[Crimson]

Thanks i like the nine ball one it looks better but i ordered the fab one because it was half the price plus it was free shiping

[kruck]

Yea, just ordered one of the FAB ones, cheers.

[Duckling]

Duckling, one more time I have to correct you.

 

KSC DOES NOT OWN any part of the KWA factories in Taiwan. We are their OEM, that's all. On the other hand, KSC does have their own factory for models that we don't make for them.

KWA permitted to sell KSC guns when were sharing the cost of making the gun. (usually the molds). That WAS true many years ago. However, KSC engineers is NOW part of KWA and under OUR payroll!!! They transitioned to KWA in 2007. We design and own all new molds for NS2 model guns.

 

KSC MP9 not coming in US because KWA have our own MP9 using NS2 gas engine. KSC MP9 is still using Hardkick engine. I guess you haven't read our product announcement during Jan Shot Show 2010.

 

As for Umarex, I wouldn't call them existed only because of H&K license, they also have Walther licensed products plus a full line of Paintball and Air-gun products. They operates very much similar to ASG (Action Sports Gun) and Cybergun.

And one more time I must say, that that you yet have to prove that you are just remotely credible.

 

Last time we had this discussion the KWA Mp7 were designed in the US, and completely different from the KSC version.

KWA-USA practically owned the KSC factory and NS7 were an exclusive system, not remotely related to the KSC System7.

Statements that turned out to be... less true.

Also, it is strange that the name "SN2" is only used by KWA-USA.

Also, the company KWA-USA, is as far as I can see just an import company, reselling the KWA range in the US. But again and again you talk about the KWA-Taiwan company as "your" factory. A connection that only you seem to make.

 

 

We just had oure IWA-2010 trade show, and the Mp9 is coming out in Europe too. Just under the true name and with Trades, as ASG is holding the B&T license.

(... and ASG is not "Action Sports Gun")

 

But the Mk.23 is new to me, I presume that it would be a System7 model?

And if so, have the hammer system had the overhaul it needs so badly?

And will we see the KSC version of this before the KWA version hits the marked as? As it have been the case with all System7 models to date.

[Danke]

One day I sent Alizard a PM and before you know it I had folks at KWA USA in the loop also. I'd believe he works where he says he does.

[Connery]

No, it's true that Allizard works for KWA USA, the main US based distributor of KWA products. In fact, I wouldn't put it past them if he is one of the VPs of the company.

 

Now, if one is trying to imply that Allizard is employed by the people that actually manufacture the guns, then they are taking the ######.

[aznriptide859]

Question for those running the MP7 as a sidearm - how on earth are you holding them? I did have a semi leg/hip holster, but this past weekend I snapped one of the buckles - ACM materials FTL.

[Connery]

Guarder Tornado Holster works wonders if you don't care about a certain look.

[aznriptide859]

Guarder Tornado Holster works wonders if you don't care about a certain look.

 

It fits in there?

 

Hmm I'll try that out when I get back to my room - didn't think it would be big enough to fit the MP7.

[Connery]

Should fit at its biggest setting with the foregrip folded. At least, it did in the one I tried.

[aznriptide859]

Is this with the rails attached or detached?

[Connery]

I fit it in without the rails. Not sure about with them on.