01-07-2011, 05:53 PM
Join Date: Aug 2005
My Ride: F30 328i M Sport
Usually to do something like that, it has to be piston-driven, or needs an internal recoil spring. I am not familiar with that model, but if I took it apart and studied it for 3 seconds I could tell you exactly how it worked. My guess is that there is a short bolt carrier in there, with the recoil spring being mounted either directly behind the bolt, or more likely being mounted in the gas key raceway above the bolt carrier. Just looking at that design, and supposing that it actually worked, I would seriously question the reliability of it.
Originally Posted by shwagon
How is this done?
Wheres the buffer spring?
I'm not sure where the rifle you posted resides in terms of type of operating system, but the front sight post is a direct-impingement gas block design, which leads me to believe it's a DI AR, and most likely a custom build. I can't foresee that being a production weapon. I could be wrong, though.
There are two major designs on the market for AR pistols that don't use receiver extension tubes.
Olympic Arms OA93 utilizes a recoil spring mounted above the barrel, and a short bolt system.
The Rock River Arms PDS Pistol is a piston-driven pistol that uses a purpose-built bolt group and a recoil spring above the barrel. This is a very similar system to the H&K G36 operating system.
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