G3SG1 to HK21 any ideas on how to ???

[dane]

i am looking to make a HK21 but i am not sure how to or where to start i am just wondering if anyone has done this before ? :-?

[Gryphon]

Oh geez.

I had wanted to do the same thing but found no really acceptable options. Let's take a look at the gun first:



For starters, the foreend of the HK21 is considerably longer (by 5 inches) than the G3. However the casual observer would likely not notice. The second problem with the foreend is it's set up to change the barrel quickly and looks much like an MG42 from the right side, and a slimline G3 foreend from the left usually with a grip that protrudes at an angle. Duplicating that would be near impossible for the average builder. My recommendation: full length rail system and vert grip if you prefer either on the side or pointing down.

The receiver is also a bit of a problem because there is no belt-feed conversion for it in airsoft. You could use a bulky box mag to conceal the magazine well, or if you decide to use G3 magazines you could pass it off as an HK11, essentially an HK21 with a mag well adapter fitted (see pic). Either way a metal body should be a priority.



The buttstock's closest airsoft equivalent would be the PSG1 stock without the cheek rest. That makes battery storage an issue, making the box mag option more attractive if you can squeeze a large battery into it. The SG1 stock could be used I suppose although it's not the proper profile at all.

The outer barrel would need to be heavy if you went with a long version, and the MC51 barrel extensions seen on the market would likely fit the bill nicely. Alternatively you could butt the flash suppressor up against the front sight tower as on the HK21E.

Rear sight would be a problem. Haven't seen anything like it in airsoft and I doubt a real one would fit, nor would you be willing to pay for one. Might be able to replicate something out of resin or aluminum.

In any case, such a project will end up costing you a LOT of money and still not quite look the part. Word has it that VFC/GB-Tech was supposed to be making an HK21 AEG, although they've been saying that for some time now and last report was it was put to the back burner. If you're looking for a good support weapon my recommendation is to check out the CA or Star M249, or other kits that would be easier and cheaper to convert such as the Guarder RPK kit. For the cheapest conversion to quasi-HK21 I'd go with the PSG buttstock, heavy barrel, and RAS, but I don't think you'd be entirely satisfied with the results. Especially lacking a metal body the RAS would probably stress the flimsy TM plastic receiver and eventually break it. Like I said, lots of cash needed for this project. But if you pull it off I'd be most interested to see the results!

[made Man]

Someone on BCAC has a HK21. I suggest you ask there.

[BC_K]

Here's BCAC's link Dane. :wink:

http://www.bcairsoft.com/forum/

BTW, I seen that HK21 in person before, year or so ago, The owners box mag wouldnt feed heh.

[Mantelope]

I've considered making one as well, but I thought the MSG90 stock would more closely match the real one.

[Gryphon]

Nope, the MSG-90 butt is more of a standard G3 butt. Compare, MSG-90 butt/HK21/PSG butt:

[dane]

Well I have the PSG1 butt all ready so I will go with that

[JOHNUSA]

here are some pics of mine 80 % i would say

http://youngstownpub.com/hk21.html

[morsredigo]

http://www.airsoftcanada.com/showthread.php?t=32094

[mateba]

from my experience, shoot for a HK11e. itll come together a little easier. And far as the quick change barrel goes, you are on your own. Hero's makes a drum and a c-mag for the G3. The c-mag is a bully but in real life you would see more 50rnd drum around. G3 c-mags are not mil-spec.

http://heroarms.com/hero%20products%203.htm
My c-mag cost 150 so check with hero's for a local dealer, i saw the drum overseas for $70us at cobrayairsoft. The CA kit IS heavy but wait until you are hold three more lbs on your gun because of that magazine. Mine is around 11lbs with the battery.

If you need a solution for the k grip go out and buy a rail and make it fit on your fore grip.They are $10-50us depending of the size. Mine is from NCSTAR and they may have a red dot scope for you if you check out their website. Ill send a pic of my gun tonight but here is some more real steel.


With the money you save on not buying the RIS/RAS (which I have yet to see on a HK) just to use a vertical grip you can go buy that drum mag or a some other accesories worth their weight in gold, like a good sling. THAT THING IS HEAVY! Your fore grip might wobble some like mine did, try to fill up the gaps with duck tape or black tape.

another option is to let the G3 experience some regression. this is my G3 before I got my c-mag. Alot of sawdust and time but its sexy and the wood stocks can be found for <40us.

sorry about all the big pictures

If you want to make an aeg a SAW i think their nothing to stop you except that you will have a SAW and the maintenance involved. I'm trying to prevent some of the damage by not increasing the the ROF or the FPS over 350. Just try to build your gun so the cheap thing break. For example, the piston instead of you mechbox. Good luck!

[Boche]

The G3 w/ wood stock and foregrip brought a single tear of joy to the corner of my eye.

On a side note, how did you resolve the battery issue?

[mateba]

i can fit a 9.6v crane battery in mine. It is best not to remove it once its installed because of the butt plate and to recharge I took the stock as a unit off. Right now the plate is off because I bought a cheap battery and the leads broke.

but to do it you need about a weekend (roughly 10-15hrs) you can blow off and tools. I used a file that is a little wider than the battery for the contour. I also used a drill with a stick file for the side walls but its unnecessary, you can use a narrow flat file. You might wont to find a dremil and a narrow chisel for the fore grip though. Unlike the mod on Anriesairsoft I did not damage any part of my gun to complete the wood stocks. Their way is easier, quicker and the fore grip will be a little stronger but you don't have to if you don't want to.

In fact ill sell my wood stocks! $60US + shipping (i live in Alabama US)
Ill make a new post elsewhere, not to muddy this one, but pm me until then.

[ThunderCactus]

ive been looking at the quick change barrel system, and you'd have to do alot of custom fabricating and modification to the reciever, not to mention make your hopup easily removable from the front.
the reason i chose the HK11 is because its mag fed, a belt feed system means lots of heavy modding, welding and machining to the body.
suffice it to say its a big project. but you could buy a G3 RAS, get a bipod, drum mag, tac handle, and get someone to make you a thick barrel extension for the front of the gun and there you go!

[mateba]

I know they look cool, but how many real HK11 have you seen with a RAS? If you want to put a vertical grip on your gun you can do for $30. If you need a front end try to get the real stuff and make it work. If you decide to do your own searching you might find more when searching HK91 vs HKG3 or G3. HK91 is a model number and as an import they are commonly referred to buy their numbers. ie HK94 = MP5 (usually with a longer barrel to meet gun laws)
http://www.cheaperthandirt.com/MGR282-1428-985.html
by the way the but stock will work too
A quick change barrel system sounds cool but a lot of trouble. send me a pick when you do it.

[Flippy]

This is HK11-ish like... Manual wind up. Now thinking on the HK21 belt feed electric one...