KJW M4

[Number5]

This is a little out of left field, I don't know if this has been discussed before on any airsoft forum, possibly has but Ive never seen it mooted:

Would it be possible to make an all in one inner and outer barrel?

What, if any, are the reasons for there being a separate inner? Materials?

It is potentially a machining nightmare with the tolerances required, perhaps this is the reason we have seperate barrels?

Would it make for a much more solid hop unit also being interested into the outer?

Just thinking about it I would guess that the hopup and machine tolerances would be the 2 big obstacles, but is it at all possible? Would it offer any significant advantages over the 2 barrel design? Possibly a conversation needing a topic in its own right...

Apologies if this is a stupid question!

I'm going to in someway answer my own Q here by adding that having 2 separate barrels makes it less likely to be confused with RS, and also ppl can't say that it's easily convertible to fire live ammo. Plus the hop up just isn't coming together in m head. I think you'd have to lose the hop bucking an just have a contact pad, I'm sure there are better ways.

[sandstorm]

Don't forget that separate inner and outer barrel make things like the KJW at all bearable. You don't wnat to think of full-length inner barrel and the muzzle velocity it'd run at.

 

Or the trouble it'd be to adjust the muzzle velocity while retaining any sense of usable gas consumption.

[alex chang]

+1 for mag conversion kits with higher bb count.

 

I think even 40 would be a blessing.

 

Another idea regarding reloading mags. I'm still using the tube and plunger technique, I know if you enlarge the hole to the magazine cap you can just use a speed loader directly into it. I've tried it and actually ended up cracking the cap as the hole was weakened due to the removed material.

 

How about something similar to the cap they have now but just with a bigger reinforced hole to allow use with speed loader without modification?

[frogfish]

good point on that one! I actually use the plastic ones and a speed loader but have a hard time getting those last rounds in there.

 

More round count is fine, I think someone might chime in with the "but realistically it should be 30 comment" to which my response has always been, no-one is forcing you to load XX amount of rounds, use what you want.

[alex chang]

Its slow at work today so here's another question.

 

Has anyone done any tests regarding fps consistancy and barrel length?

 

I know with any gas gun longer barrel = higher fps (to a certain extent). As there is more volume for the gas to expand the higher the fps.

If there is a longer barrel, and gas expansion is effected by temperature. Wouldn't a longer barrel lead to more fps variance as there is as the bb is essentially subjected to the variable gas expansion longer?

 

IE simply put:

FPS = Gas Expansion * Duration (length of barrel)

 

Wouldn't decreasing duration the bb is subject to the variable (barrel length of 363mm to 300mm) decrease the effect of temperature variable thus giving more consistent fps?

 

Or does all that happen so fast that its negligible?

 

Maybe someone with two different length inners can run some tests. Obviously the fps range will differ but perhapts we could see if there is more consistancy vs barrel length in gbbs?

 

I don't know once again just a thought i had. Maybe thats why Tanio Koba designed the inner barrel so short =p. Hopefully someone can enlighten me since I don't have a science background.  

[Hut73]

Another idea regarding reloading mags. I'm still using the tube and plunger technique, I know if you enlarge the hole to the magazine cap you can just use a speed loader directly into it. I've tried it and actually ended up cracking the cap as the hole was weakened due to the removed material.

 

 

The trick is a sharp 3/8"(meaning, the newer the better) drill bit.  3/8" makes the hole just a bit wider than the extension on most speed loaders, and should eliminate any stress on the loading tool "tube". 

 

Also, something else that I did was to cut about 1/8 to 1/4 inch off the end of the loading tool tube.  That eliminiates any gap in between the end of the loader, and the point where the inner diameter of the loading tool necks down which can cause bb's to jam during the loading process.

[Theme57]

For my reloading I cut mine in half. So I get between 30-32 bbs per load. TO keep it together I dremeled the opening on both sides so they expanded a little so coming apart from the 3 reloading parts wasnt a problem. I then made a slit around the rod and put some teflon tape so while it was fully in it wouldnt come out unless I pulled it out, oddly enough being very easy too haha.

 

I will say user error is more apparent this way due to if you forget how many times you have plunged your mag, then over loading could be an issue, yet it does help with reloading a half empty mag since I load 15-16 bbs at a time. It also make plunging a lot easier as well.

 

In short:

Cut down the rod and tube to only allow 16 rounds tops. Make a slit(s) on the loading rod so it will stay in the tube unless you pull it out. Use a dremel to expand both sides of the tube along with some teflon tape to secure the tube, cone and loading square thing together tightly, but not perminately.

[Roman!]

You guys have already covered the topics I first thought of concerning mags and real steel parts.  The biggest pain to me is, as someone has already mentioned, loading the mags.  Some kind of metal smallish loader you could easily carry in a pouch that would load the mags would be worth its weight in gold.  The plastic rods do work, but even cut in half they run the risk of breakage if you are carrying them on the field.  Not sure what it would cost to machine something like that so it may not be worth it. Just a thought.

[Roman!]

After some additional thought, how about a metal adapter to place over the mag to allow a standard pistol mag style loader fill the mag?

[delarosa]

Actually by using the stock loading adapter (removing the tube), you already could use normal speed loader to load the BB, you just need to make the hole on the adapter bigger, thus the mouth of the speed loader could fit in. A metal speed loader would be great instead of current plastic ones which could break anytime.

[Hut73]

You guys have already covered the topics I first thought of concerning mags and real steel parts.  The biggest pain to me is, as someone has already mentioned, loading the mags.  Some kind of metal smallish loader you could easily carry in a pouch that would load the mags would be worth its weight in gold.  The plastic rods do work, but even cut in half they run the risk of breakage if you are carrying them on the field.  Not sure what it would cost to machine something like that so it may not be worth it. Just a thought.

 

 

The small pistol loading tubes and rods that used to come w/ KWA/KSC pistols work perfectly for what you're referring too.

 

After some additional thought, how about a metal adapter to place over the mag to allow a standard pistol mag style loader fill the mag?

 

That's an excellent idea!

 

Actually by using the stock loading adapter (removing the tube), you already could use normal speed loader to load the BB, you just need to make the hole on the adapter bigger, thus the mouth of the speed loader could fit in.

 

My last post just above this one details/refers to doing just this thing.

[Landa]

i vote on drop in upgraded hop up unit and STANG mag conversions.. i have 7 mags.

[alex chang]

In addition to those mag conversions maybe draft up some better gas route seals? I know there are a lot of gimmicks out there for airsoft that don't do anything but i swear by these in my pistols. I've tested multi mags in different conditions and have always had better results with these. I'd be cool to have a drop in addition included in the conversion kits.

 

http://shop.ehobbyasia.com/nine-ball-gas-route-sealing-rubber-packing-for-marui-hi-capa-p226-gbb-2pcs.html

 

 

[t_hum]

FYI: we started on stanag conversions and also billet mag loaders designed for use with speed loaders. We hope that both of these will be 1-2 week projects. I'll post photos of the prototypes soon.

[frogfish]

@#(*#&%$# YESSSSSSSSSS

 

 

I will be in line for the conversions, reserve 7 for me!!

[Roman!]

Here is an idea I saw in the KWA fourm for their M4.  A spring kit for the charging handle so it "snaps" back in place when pulled back to load a round like the real steel M4 does. Seems like that would be doable and a nice upgrade for realism.  

[Theme57]

Hey guys I have this outragous suggestion. Okay so we use the top of the mag (that goes into the magwell) make a base for it that had two tubes. We have that running inside a belt that looks like something you see on the Miniguns into a pouch of some kind about the size of the square hydration pouches or some kind of pouch of that size. Either in the pouch there is a device that pushes the bbs into the mag to be fired or something along the belt that feeds bbs (stay with me guys) thats tube 1. Tube 2 will be hooked to a propane tank. So pretty much it looks like a belt similar to a Miniguns that is hooked to a propane tank and had a large reservoir of bbs for a lot of firing.

 

Odd idea, but thought it wouldnt hurt to pitch. I would buy one if one was made.

[frogfish]

Why take something designed to mimic realism and make it completely unreal?

 

Here is an idea I saw in the KWA fourm for their M4.  A spring kit for the charging handle so it "snaps" back in place when pulled back to load a round like the real steel M4 does. Seems like that would be doable and a nice upgrade for realism.  

Have you ever toyed around with a real AR or a KJW M4? Something tells me you haven't.....

Edited December 22, 2012 by frogfish

[Roman!]

Not sure what something tells you that.  I have 3 ARs and 2 KJWs.  Cradle is doing the Hop Up Mod on both of my KJWs over the next week or so when they have time. It did not help that I sent in the full upper for both!  You do not like the idea of the charging handle going back on its on when released?  I thought it would be a pretty cool effect. Guess you would not be an easy sale

[Landa]

im not understanding you roman either... when you release the charing handle, it will go back, being pushed by the bolt carrier, which is itself being pushed by the buffer spring... there is a spring in place already... you mean make the charging handle go back when the bolt catch is engaged? how is that realistic? no AR does that?

 

theme, what you want can be easily done by you tapping the mag for HPA (and getting an HPA rig) and then making something like this:

 

 

this is essentially a hi cap for GBBR mags...

Edited December 22, 2012 by Landa

[weekenny]

Ah hang on, Roman do you mean releasing the bolt catch by racking the charging handle when you insert a new mag? If so then the KJW already functions like that.

[Roman!]

Well, maybe this is a case of mine not quite functioning right.  Once I rack my charging handle, it does not snap back all the way.  It kind of just sits just outside the charging handle lockup point.  It does not have the snap of the real steel.  Maybe I just did not lube that part enough so it would go all the way back into lock up?  When I get mine back I will revisit this.  Not having other KJW owners around to compare results too may have colored my perception. Guess I need to ask more questions on the fourm, but I honestly just thought it was an "airsoft replica thing" and did not really look into it. Oh well, good to know I may be able to get mine to do this.

 

Moving on, and on to better ideas, does anybody make a tactical charging handle yet for the KJW like BCM's model for the real steel?  I know it is not really practical on an airsoft gun, but it looks hella cool!  

[weekenny]

It should snap right back to where it started from without issue.

[Roman!]

Thanks Weekenny, I will look into this when I get my uppers back. Now that I know it should, I just have to figure out what the problem is on my end. The charging handle was stopping a few millimeters away from the charging handle lock point on the upper. I had to push it slightly to complete the lock up. I wonder if I have my bands on the bolt assembly correctly?    

 

The biggest part of the  problem was just my just accepting what it was doing without looking into it any further. I will clean, lube and check for any points of contact etc.  that may be keeping the charging handle from closing all the way. Since both of mine are doing this, and they should not be, I must be doing something wrong in common with  both in the way of lube, assembly etc.  I am red faced, but it has to be operator error.   

[frogfish]

Yeah it should go back all the way just like the real deal. Don't ride it home, let it fall on its own, if not, function check, and try again, if not make sure everything is in its proper place. If it is, you might need a new buffer spring.