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