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Discussion Starter #1
I just noticed that after heat treating a receiver bent from an AK-Builder flat the left side is noticeably warped. Is there anything that can be done with this receiver as it is?
 

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The receiver can be straightened, I am more than sure. Can you post pics of it so we (collectively) can give you advice?
 

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howdy OJ.is it warped in the center going forward?are you using water to quench? use used motor oil to quench.water warps most of the time and the FCG holes will get brittle and crack at some point,sometimes and the oil gives extra carbon to the steel.as for the warp,stick the front and rear trunnions in the body and twist to the side of the warp with your hands/strength,if that won't do then stick the front,with trunnion in the vise,protected of course and twist from there.9 outa 10 those 2 ways will get the warp out.the other way would be to leave the trunnioned end in the vise with a block of wood near the end and heat the receiver and with a crescent wrench or anything big enough to fit over the block of wood and receiver,protected of course lol,twist in the direction to straighten while heating it,don't quench,no need to get it red hot..LOL..good luck OJ and good building
 

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I use water to quench but this is the first time it happens to me. I heat with a MAPP torch to red/orange hot then quench in water, polish with 400 grit then heat to a blue/gray, then let it air cool. This time it happened because I appled excess heat, I think... :goof:

Hi Dings! Will try your methods and will let you know. Anyway here are some photos:



 

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There's also no rails in place. Those rails will add some stiffness, in addition to the center support. I would never try to heat-treat a receiver that was not 100% finished.
 

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I think you should continue building without worry.

It's a gentle bend, so maybe a little hand flexing will help, spreading the force out along the bend. Then place the center support and it may be gone.

I agree you may have applied too much heat, maybe a matte orange color with a hint of red somewhere then quench. I've used oil and water, and water is somewhat cleaner and faster, but I think I like oil best as well. With no concrete personal evidence that the preference is justified.

I also heat treat after the receiver is complete, with the trunnions temporarily bolted in place. At this point the rails are 95% finished. So it's heat treat, rivet, fit carrier to rails for me.



I say, continue and keep an eye on it as you go. Tweak as needed.
 

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how ya doin OJ.saw the pics.not bad at all and will straighten right up.get your rails and center support in.before you do twist it straight best ya can.put a slight bevel on the front tip of the lower rails,that bump against the trunnion.this will take alot of worry and exactomundo out of lining up the rails to trunnion so if ya slip a little they will still feed the carrier well and not slap the trunnion lip.do all mine like that.no shiney spots on the trunnion lips.sometimes one side is a little lower than the other(not 1/4")etc.trim them rails down most of the way before ya spot weld em in..ask me how I know..LOL..sand both sides of the rails and the inside of receiver and you will have perfect spot welds.
 
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