PKM Rails - a question
After looking at the VLTOR receiver, I was surprised to see the entire top of the receiver has no rails bent in! Instead, everything behind the trunion is milled down flat, and machined rails are riveted into place.
I was very puzzled by this - I have assumed all along that the original PKM receiver was "just like" an AK, in that the rails are bent into the shell, not riveted in.
I was also under the assumption that reinforcement rails were then spot-welded to the inside so that the rails are double-thick.
Does anyone have any close-up pics of a military PKM receiver? I can't find much on the Interweb that has nice close-ups of the rails. :(
This is a good pic but it needs more light on the inside:
ImageShack - Image Hosting :: range28apr08012.jpg
I looked through all my pictures and I dont see any that show the double top rails, although I have seen them I just dont remember where.
You can see pics of copies on the rails in this thread. The technical manual gives some
ejector measurement specs, but only for service. I haven't enough measurements to copy the ejctor yet. I'll going through the books.
Well since I'm sick I spent a great deal of yesterday evening looking for pics and found quite a few - mostly from people taking pics of their demilled PKs.
I was able to confirm my suspicions are correct and that PBB has a closer-to-the-real-deal design than VLTOR.
There *IS* a top rail bent into the entire length of the receiver, just like an AK, and there is a reinforcement rail welded to the bottom inside of the rails. I presume this is to reinforce this area because there isn't anything else there to support the sheet metal, nor are there any reinforcement bends/spines in the receiver. I would think this would cause a great deal of flexing if the reinforcement rails were NOT welded in!
I can't tell whether or not that fancy "funnel" bend on the VLTOR ejection port is factory or not, or whether it is simply an opening as with PBB's design. Hard to tell from the pics. I can tell why they did that - it would help keep ejected rounds from bouncing back into the receiver, but it may be overkill.
So for now I am going to stick with my "plan A" and cut 4130 square tubing to build the reinforcement rails.
I posted a bunch more pics on my PKM page, too many to post directly:
Does pbb have a few recievers he is selling? Ive been on viltors list for quite a while and not really getting any where. Have one of the prexis recievers but not sure if it is really correct or not.
I may be able to get some voltor receivers.