AR upper with a relocated operating spring

[kanton]

Does anyone make a kit or have plans for an upper with a relocated operating spring and rod, on top of the receiver surrounding the gas tube?

I know Allan Zitta at ZM Weapons makes an expensive upper and folding stock kit but I would like a cheaper alternative that I could retrofit to my existing uppers for building a bullpup or pistol without the operating spring sticking out the back of the receiver.

Thanks

[Colohunter]

The ZM system is the only one that I am aware of, are you looking to be able to use a folding stock?

[nwcid]

I am not aware of a way to retrofit this type of system to an existing upper, or at least not easily.

Olympic Arms also makes/made (dont see it currently listed on their site) their OA series that also does not require a rear buffer. I never did see them selling parts just for these builds. They made a pistol version and a rifle version. http://www.olyarms.com/index.php?opt...tpage&Itemid=1



Here is a pic of the OA pistol I had to give you an idea how it works.

[Colohunter]

So what caliber is that in? That is a pretty interesting concept. The only one I had seen before was the ZM system. Where did you get it? Could it be used with any caliber in the AR?

[nwcid]

I only saw them in .223 but I assume you could use it with any caliber you could get/make a barrel for. The barrel and most other parts are standard.

I dont know why you never saw these, they have been selling (unlike ZM) since the early 90's and tons were sold. As stated they are the OA series rifles/pistols (pistol pictured) made by Olympic Arms in Olympia, WA.

Right from the Quarterbore Forums, http://www.quarterbore.com/ar15m16/oa93.htm

[kanton]

Colohunter,

I am not interested in a folding stock but building a bullpup or pistol without the operating spring sticking out the back of the receiver.

Does anyone know if Olympic Arms only sells complete OA series weapons not just uppers and parts?

Thanks

[nwcid]

When me and my buddy were getting ours they were only selling complete guns but that was right after AWB ended. I dont know if that ever changed or not.

I do not see them listed for sale at all right now but I would call their 1-800 number right on the website and ask.

[Colorado Osprey]

I thought ZM was making them under license from Olympic.
Just like Dedicated Technology is making the WSSM Ar's under license from Olympic.


Because of demand for vanilla Ar's Olympic is running overtime just trying to keep up with demand. Alternate caliber stuff and non standard AR stuff just isn't being made.(or at least turning out very slowly)
For example the K23P (Standard AR pistol) orders are at least a year behind. The OA-pistol series like the one shown above haven't left the factory since the election. The OA series carbines like mentioned above have been discontinued. They only sold a couple hundred a year.

For alternate non-standard AR's, Olympic is now concentrating on the "sporting and hunting" market with their 30 cal WSSM called the 30 OSSM which exceeds 30-06 energy and velocity.
They are supposed to also release a .458" version that exceeds the 45-70.

Both of these cartridges put the 30RAR, 458 SOCOM and 450 Bushamster to shame. Big boy power without getting into the big boy AR-10 chassis.

[JFettig]

ZM and OA are different systems all together.
I wish I could find my pictures quick.

ZM has a short gas tube and a long key that goes over it, the long key also has the spring that goes over it.

OA has a standard style gas tube and the recoil spring is above that.

I've handled a ZM in the gun store, it seems kind of stiff charging it, it still uses a charging handle in the standard position, it is different though if my memory serves me correctly.

There is a guy on ar15.com who made an AR pistol with a similar spring config as ZM, it turned out pretty slick, he also added a forward charging handle which I believe is non reciprocating. see attached.


Jon

[kanton]

Jon,

Thanks for the information. Could you provide a link to the article at AR15.com?