I hate to sound stupid but how does the gas piston come off on the AMD-65? Does it just unscrew? I dont see any pins or anything that is holding it on. I have tried to just unscrew but it wont budge. Any help appreciated!
Take a wire wheel or some sandpaper and sand the finish off the end of the bolt carrier where the piston is screwed in. You will find a pin underneath the finish. I couldn't see mine either until I did this. Take a punch and tap the pin out and unscrew the gas piston. If you are replacing it with an american one you will have to drill a hole thru it once it is screwed on so you can re-pin it. Do not tighten the gas piston all the way. There is suppose to be a little wobble in it. That is why they pin them. I hope this helps. ak'sr4me
A little dykem can help locate the pin.
You can't see it too well in this pic, it colors the two different metals slightly differently, also it leaves a slightly darker ring where the dykem seeps into the joint.
The pin runs horizontally through the carrier @.375 back from the joint.
The pin is actually "bradded" on both sides, so you might have to drill with a slightly oversized bit, a little, and then use a punch.Make SURE you find the exact center of the pin before you drill. You will probably not be able to reuse your old pin. I always use a 1/8" new pin. There should be a small bit of countersink on each side of the hole, if not, use a bit slightly larger than the hole, and countersink very slightly.(This will be where the new pin will be bradded). To install the new pin, chuck your 1/8" bit in your drill press. Then clamp your bolt carrier in your drill press vice, where the drill bit will pass through the hole in your bolt carrier when you lower it. Then screw your new gas piston into the bolt carrier, making sure nothing moves. Then drill through bolt carrier hole and new piston at the same time. Trim new pin about 3/32 longer than the length across the bolt carrier, and install. Use a small ball-peen hammer to brad both sides of the pin into the countersinks. Then, file and sand to perfection.