Hmmm... Now that's interesting!
So, with a Romy RPK trunion, I'm wondering how that would work attaching the trunion when the receiver is wider on the 47ES than the regular 47??? Would I need 'shims' or something to fill the gap?
Hmmm... Most interesting. What thickness(es) of Flat Bar are you using?
Hmmm... I'm guessing if done with a screw build format like this, you could probably later go through & rivet the whole thing together, right?
I'm most anxiously awaiting the build thread on this! The sooner the better! :)
Shim each side for what ever trunion you are using. I used 1/8" thick FB for the ES receiver. I screw built first and intend to rivet all together now after fully functioning.
So, for the bolt rails (upper on an AK) that the carrier slides on... Did you use 1/16" (0.065) or 1/8" (0.120) angle iron???
IIRC, 1/16" (0.065) steel should work for rails without having to be milled down like the 1/8" steel, right? Or did some of you just widen the rail channel in your bolt carrier(s)???
It looked like most everyone milled down their steel tubing on the original style to fit the rail gaps in the carrier, but cntrailrider's friend who built one - his appears to have a wider rail channel on what appears to be a highly modified / custom bolt carrier.
I'm thinking for stability / longevity sake, I'm likely going to just build mine in the original welded format. But I'm eagerly awaiting your most excellent tutorial so I can perhaps borrow bits & pieces of ideas from your 47ES build tutorial.
I found some steel in the hardware section at my Home Depot, not a very good selection. I got square tubing at a family owned hardware store.
Originally Posted by iNuhBaD
The rails are 1/16. The rail slot in th BC did not have to be widened.
Awesome job SS! I can't wait to see this!
WOW!!! Thanks for the great information, SharpsShooter!!!
I'm thinking perhaps now I WILL do my build in the ES form... Does your trigger mechanism (which doesn't NEED a pistol grip to operate) somehow work mostly due to increased space in the receiver? Or how does this work? I'm dying to see pics of the FCG internals, and the overall dimensions of the receiver (Width, Height to NEW 'top' rail), and especially your bolt carrier design/modifications!!!
I'm sooooooo excited to see more!!! This is a SWEEEEEEET BUILD!
Another quick question... How does your cocking handle work? It appears as though you'd likely have to open the top cover to pull the bolt carrier back in some way... How did you do that?
I guess these are all things I'll have to wait to see when your tutorial comes out, but I'm getting really antsy. My wife 'approved' some funding to further my gun builds, and I need to purchase some parts soon before she either changes her mind, or something 'else' crops up needing repairs on our 'money-pit' house of ours. ;)
The FCG is modified AK. AK FCG fits inside a standard width AK receiver so there is extra room in the wider and deeper ES receiver. There is just enough room between the TC inside and the receiver outside to get a cocking handle bracket in between. Cocking with the TC open would not actuate the feed mechanism and the belt would not advance and feed round into the chamber.
Thanks for the info...
Thats what I was kind of wondering about the Charging handle. I knew it wouldn't actuate the feed mechanism with it open... I was thinking you had some way to lock the bolt carrier back with the TC open, feed a belt into position in the tray, close the TC, and THEN release the bolt carrier to chamber... I thought that would be overly complex, and you MUST have thought of some better way to do it... (which you did)
That makes more sense...
Also, so that means this receiver is also taller as well as wider than the original MG-47...
What advantages do you see from using a wider receiver (if you were to make one in a weld-build)? Is it just more room for recoil spring assembly options, or what other justifications (although I realize it's necessary in its screw-build form to be larger), but are there any additional benefits/advantages?
I kind of like the thin, compactness of your MG-47 weld build receiver in that it's smaller, lighter, and thus not so unwieldy. Not to mention there isn't the trunion shimming requirement either.
Could I do this with a piece of RECTANGULAR stock to get more vertical receiver space, but still keeping it skinny enough to keep it lighter and keep soem bulk down? I'm thinking 1 1/2" W x 2 1/2" H x 0.12 Thick (Maybe grind/file/sand/mill down to ~0.06" on one side), and then cut the rail for the bolt?
Since I don't have a mill, it'd be tough to get the one side down to 0.60 with any relative consistency along the length of the receiver... But the 2.5" high tube should allow me sufficient clearance for an AK trigger group, and the bolt carrier... Maybe even with 0.05" to spare, LoL!
For mine, I've been thinking of somehow adapting an H&K G3 style cocking handle along the length of the receiver with a bolt hold-open of some form.
If you uses 1 1/2 x 2 1/2 x 1/8 tubing how are you going to mount the BC guide rails? I measured a Romey BC at 1.251 wide , a Yugo M70 BC at 1.257 wide and a Chinese AK BC at 1.291 wide. 1 1/2 x 1/8 wall tubing is approximately 1.125 wide inside. That doesn't leave any room to bolt, rivet or spot weld in the BC rails unless you point the leg of the rail up in the receiver, then you don't have room for the ejector and bolt head guide rail. 1 1/2 x 1/16 wall tubing would give you room for 1/16 thick angle to make your rails from. You could still use AK FCG in the thinner wall tubing. But 1/8 wall gives you a very stiff receiver. Cntrailrider had to attached some stiffing rails to the sides of his 1/16 wall receiver because the side force required to actuate the feed cam would deflect the receiver. Check CTR's posts to see what he did exactly.