Is there a semi auto version of the LR 300?

You could make a clone using one of the various systems, but each of those systems is different enough from the LR300 that if you want a direct clone, you're *almost* better off making it yourself. The FM15 is the closest representation, but is different enough that it isn't a clone, at best it would be an homage. > The LR-300 uses a modified version of the AR-15's standard direct impingement gas operating system dubbed delayed impingement gas system.[4] The gas key is extended beyond its normal length (manufacturer calls it an "operating rod"), extending into the handguard. The gas key contains the return spring which is fixed between the front of the receiver and the collar at the front of the gas key. The gas port is under the back side of the gas block, gasses go up then forward to the front side of the gas block then up and back to the gas tube. The gas tube is about half of the length of a standard AR-15 tube. The gas tube is always inside of the gas key (minimal overlap is about 1 inch). This leaves the area near the bolt much cleaner. Almost all gasses exit the gun through the holes on the right side of the bolt carrier, and minimal leaks from the gas key to the handguard area do not hinder the gun's function. Upper > To accommodate the unique forward buffer and gas impingement system, the proprietary upper is taller and thicker than a standard AR upper.[4] The handguard rail has a removable top cover to access the recoil spring system for disassembly. The charging handle is proprietary and has a beefier design to fit the op-rod.[6]