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Posted: 11/20/2002 10:00:33 PM EDT
Must have had some open time on the Bridgeport today, as I cut the channel to length, and trimmed the top rails to width, and shape. Other than not having the mag dimples, this thing will make a decent rec. Might make up a punch and die setup to put them in. A set of rails welded in and its good to go after some drilling, and mag well cutting.
Just a little heads up for anyone wondering about those channels, as I did.
Pete
Link Posted: 11/21/2002 4:04:35 AM EDT
[Last Edit: 11/21/2002 4:05:24 AM EDT by CAMPYBOB]
Link Posted: 11/21/2002 10:31:02 PM EDT
Bob,
I must be some sort of binge worker. I get so focused on a project that I have trouble stopping long enough to get the camera (or go eat or anything else for that matter))and snaping some pix. Some time I'll line up some of my junk and deluge you with photos. Did you get the ones of the cam buck bar?
Likely need to sandwich the rec. side between 2 pieces of metal, with an oval hole in the outside one, then punch your dimples, thereby getting a nice factory like result.
Pete
Link Posted: 11/22/2002 3:17:26 AM EDT
Link Posted: 11/22/2002 9:57:28 PM EDT
CB,
I tried sending them to your email. They didn't come back as a failure, so I figured You got them. I'll try over the weekend.
Punching through a block clamped to the outside of the channel would give crisper detail by holding the metal around the dimple area down tight. Have to rig up something to keep everything lined up though.
Pete

Link Posted: 11/23/2002 12:46:07 AM EDT
[Last Edit: 11/23/2002 12:46:52 AM EDT by mg34ss]
Remember to soften the edges of the male die so you won't cut the metal. I lost one when it sheared rather than punched. I have to get two of those channels myself this winter.
Link Posted: 11/24/2002 6:49:35 PM EDT
Will the bent metal channels work with out creating dimples and does anyone have any pics on completing one? Do the holes need to be heat treated after it's finished or can they handle without it? One more question can the ak-74 trunions be attached with screws to these? Also what other stuff has to be done to these?
Thanks
Link Posted: 11/25/2002 6:16:36 AM EDT
What are the rails fabricated from?
Other than spot welding in rails, is the rest of it just opening up the top, cutting length, drilling holes (including trigger & safety), and opening up trigger and mag well openings?
What about heat treating?

I do not want a receiver that says HESSE!!! The OOW may be decent, and Global will be offering receivers this upcoming spring.
Link Posted: 11/25/2002 9:48:29 AM EDT
Link Posted: 11/27/2002 2:54:31 AM EDT
Well, so much to review...
You do not have to press mag support dimples in your home rolled receiver. The new RPK-74 does not have them. The rails you can get from SKSMAN have sufficient "meat" to support the mag. Be careful tigging in the rails. You can overheat them and loose the temper. Then your ejector will peen like a soft nail. Someone reported using screws to install his rails. Just another option...
Heat treat is a hit or miss thing. It is almost impossible to do without a furnace. Using a oxy/acet torch is a waste of time. Half of your receiver will be molten, half cold, and the oxide scale will be too thick to successfully remove without a hammer, which will destroy the receiver. Don't even try that method. Also, once you get it hot, you have about 3/4 of a second to quench it. The thin sheet metal will cool past the transformation range in air very quickly. You need to "shock" it to get any hardness at all. There are two up's to this. #1. you can test your technique on some scrap pieces till you get it right. #2. If you blow it, you can anneal it and try again. DO NOT weld in the rails BEFORE you treat the receiver! Do not quench in oil. 4130 will not harden like 4140. You will have to use extreme quench techniques (water)to get any hardness at all. Also, if you quench in oil, forget about black oxide. You will never get the oil out of the pores in the steel, and the oxide solution will bead up and roll off.
A ceramics kiln is a great heat treat furnace. You need to go slightly over 1650 F. There will be considerable scale oxidation if you leave it in very long. I've had luck with a five minute soak. So heat the kiln before you put in your metal. Have your water quench even in height with the top of the kiln so you can pull out the receiver and quench it in 1/2 second. I use a piece of coat-hanger wire run thru a hole in the receiver. Remember, the wire will be more like string than wire at elevated temperatures. Use welding gloves and KEEP YOU FACE FROM OVER THE KILN. If you've been successful, the receiver will "ring" when you tap it. If you did it wrong, it will go "Phlud".
That about covers home heat treat. One additional thing worth mentioning is that heat treat will cause slight warpage so the thinner the sheet metal, the less spring pressure the screws will have to overcome to hold it square again. I destroyed 18 receivers learning how to do this correctly, so I'm speaking from wretched experience, not hopeful speculation.
Good luck.
Link Posted: 11/27/2002 11:22:07 PM EDT
Super review on the heat treat! I do not mean to carry on about the Hesse receivers, but they are straight, and heat treated. The OOW rec. are not, except for the pin holes, and the ejector. I wonder how important the HT really is. I know the pieces of channel that come off the trunions in the kits are almost spring like, try drilling one, quite hard! Obviously the foreign mfg. feel it necessary. Are they treated for strength, wear resistance, or both? I wonder if there are any old builds out there. What has been the experience of those with many rounds thru one of the untreated rec? Pete
Link Posted: 11/28/2002 4:24:18 AM EDT
Link Posted: 12/4/2002 11:27:11 PM EDT
I was talking to Bob Landes about his VZ58 project. He said, as I recall, that they were milling the rec. out of 4140, and spot heat treating with a torch. I think that if I were to mill an AK rec. I would make it out of brake die, and spot treat only the locking lugs, ejector, and perhaps the pin holes. The BD would be just fine for the rest, as I see it. Not anything I have time for at present though! How long did it take you to do the one you had messed up?
Pete
Link Posted: 12/5/2002 3:51:30 PM EDT
Hi all'

back and all sorted out from jet lag,

I am the one who assembled the rails with screws, I am gettting ready to do a bulg. 74 with a bend metal, I am at this time trying to decide whether to weld the rails in this time, The rest will be screwed together

screw the rails from the inside, except where the mag pops through, ( you can trim the heads with a dremel, and this will help with a wobbly mag, but you can't remove the screws).

I utilized the scope mount to tighten the right rail no movement, the heads must be turned down and a small hole drilled in the end to peen when complete,

sprat
Link Posted: 12/6/2002 7:57:25 PM EDT
A suggestion for welding the rails in. Many bodyshops nowdays have spot welding equipment that is quite sophisticated. The process is known as STRW (squeeze type resistance welding). This might be perfect for the AK rails, and is how they are installed at the factory. Might be worth looking in to, if you can find a friendly bodyshop guy with one of these welders.
Pete
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