Confirm Action

Are you sure you wish to do this?

Confirm Cancel
Member Login
Site Notices
10/20/2017 1:01:18 AM
9/22/2017 12:11:25 AM
Posted: 9/5/2005 2:16:41 AM EDT
I am just getting finished with my very first M4 clone and first AR series rifle ever and was surfing the web looking for my next AR "project-to-be" and I came across a website that had AR rifles with what looked like folding stocks! I fully meant to bookmark the site for future drooling and possible purchasing but my stupid POS browser crashed from too many windows open before I could even finish reading the specs. The rifles looked like a cross between an M4 and a SPR and the website had a few different variations.

anyways, my question is this, have any of you ever seen or know of the website I am refering to? I am really interested in one of these as I love the M4 and SPR rifles and building an SPR, especially one with a folding stock, would be REALLY cool and original.

Link Posted: 9/5/2005 2:23:17 AM EDT
Link Posted: 9/5/2005 2:29:33 AM EDT
Damn your fast! Bookmarked both of those sites as soon as I checked them out plus I found more new parts for my existing gun! thanks a ton shawn!
Link Posted: 9/5/2005 10:19:20 AM EDT
Link Posted: 9/5/2005 10:25:48 AM EDT
I'm new to the AR as well, but could someone explain to me the way this rifle functions without a buffer tube?


Link Posted: 9/5/2005 10:28:37 AM EDT
I think they are piston uppers.

Olypic had a standard gas system upper though that used a shorter bolt carrier that would allow a folding stock.
Link Posted: 9/5/2005 11:19:27 AM EDT
[Last Edit: 9/5/2005 11:33:17 AM EDT by Duffy]
They are not piston uppers. I owned a ZM for a few years, it's simply a modified buffer system. Instead of the buffer behind the receiver, it's on top of the barrel surrounding a larger diamter gas tube, the bolt carrier is propreitary mated to the said larger diamter gas tube (it's staked on), when the upper is assembled, the larger dimater gas tube telescopes a shorter and thinner gas tube that's fixed to the upper, which channels the gas from the barrel. The return spring in turn surrounds the larger diamter gas tube (with the attached bolt carrier) Gas goes through the short gas tube, pushes the bolt carrier back, when the energy is spent, the return spring returns it to battery.
Same bolt, gas still gets blown into the bolt itself.

Because of the unique bolt carrier, the auto sear has to relocated.

The OA97 does it pretty much the same way, though with much less refinement and aesthetics, it's friggin' ugly. Its folding stock is from Ace. While the stock itself is light and sturdy, the folding mechanism sucks major ass. ZM/YHM uses a modfied FN folding mechanism. Simple and quick to fold/unfold, in addition to the heavy skeleton stock it also offers a LOP adjustable folding stock, it's probably one of the nicest stock made. Cheekweld is not improved and it does not have any storage capabilities (this was well before the Crane/Vltor), they really should cover it with some synthetic material so in freezing weather the stock won't get stuck on your face
Link Posted: 9/5/2005 12:25:11 PM EDT
[Last Edit: 9/5/2005 12:25:39 PM EDT by Creeper1313]
Wow I never knew you could have an AR without a buffer tube either... this would make AR pistol MP5K-forgeries a lot cooler looking (if it could even be done on a pistol)
Link Posted: 9/5/2005 1:52:16 PM EDT
Duffy.......Thanks for the explanation. You painted a beautiful picture with your words.

But really, I appreciate it....it makes sense now.

Link Posted: 9/5/2005 2:40:24 PM EDT
Ridge took some pics of the ZM's modified buffer system. I took some years ago but they're long gone
I didn't shoot it enough, so sold it to a fellow shooter that appreciated and shot it more than I did
Link Posted: 9/5/2005 9:08:31 PM EDT
I really REALLY want one but ar15club is right, the$1500 price tag is a bit steep. Unless of course the gun shoots better than a standard AR then I could justify it. But then again I have had my eye on the .308 Panther Carbine that DPMS sells.......decisions decisions
Link Posted: 9/6/2005 5:50:43 AM EDT
$1500 was a lot when I got mine in 2000, there was not a whole lot of uppers in the market that could command that kind of money. These days with the SPR upper and LMT MRP, it doesn't seem out of place. You gain a rifle that's very compact when not in use, and it's certainly unique and an attention getter. I prefer LOP adjustable stocks with improved cheekweld (e.g. Crane and Vltor), in that case the folding stock isn't attractive to me, and without the folding stock advantage, so goes the whole package for me.

However I will point out that the standard AR15/M16 buffer system can act like a hydraulic system when filled with water, this aspect the ZM.YHM addresses due to the relocated and redesigned return spring.

Some say it is a little cleaner, but it is still a Ljungman gas system at heart.
Top Top