Straightening Milled receiver rails ?
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    Straightening Milled receiver rails ?

    Im in the process of collecting parts and knowledge for two milled builds. I have two tortort receivers that are slightly wrapped from heat treat. Does anyone have a method to straighten the top rails without potentially cracking the receiver. Here are a few pics





    Also where can i located dimensional drawings of the Milled receiver and the location of the Selector stop hole . I have the dimensions for the FCG holes i would like other dimensions as well. Thanks in advance.
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    bummer. are you sure it will be an issue? how far out are they?
    also how hard are they and what material? proper receivers are springy and pop back so you'd have to go beyond a bit to get it where you want it.
    if you have a heavy steel table you can set a spacer on it could be a thin dowel or flat stock, lay the receiver on top of it perpendicular to it. and clamp down on the front and back of the receiver. you might use a LITTLE heat. I would do this rather than trying to pinch the rails together. go a little at a time of course.
    if its heat treated properly it shouldn't crack. until you went way to far. but since its warped maybe the quench isn't all they got wrong.
    before all this, will they replace them? these aren't serialized shouldn't be a hassle.
    fcg holes, recreator blanks or the guys in Colorado that make the cool jigs make a flat drilling fixture. it wont fit on the milled receiver as is because the bottom is thicker where the front of the t.g. gets riveted. but the one I have the sides unbolt.
    you can either put spacers between the sides and bottom to get the height you need or you can just take it apart and use it in pieces.
    I take extra fcg pins and turn them down to use as dowels to hold the jig in place in the gcg holes while I make the holes for the selector.
    if you have an akm receiver you can take all the dimensions from it as well. coming off the top of the receivers it will be the same.
    Sunspot likes this.
    07 ffl


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    With the top covers i have they will not fit over the receivers unless you force them. Advertised as 4140 at 42 rockwell hardness. I tried to experiment with one by clamping it to my work table and clamping the top rail and pulling it and went as far as i felt comfortable and applied some heat with a map gas torch but it just sprung back like spring steel. I was thinking about getting some rectangle bar stock and cutting them to the proper width to fit in the receiver and clamp it and try to pinch the spots that are warped. Using sections of the bar stock to support each side on either extremity of the warped section. Im just hoping i don't crack them because i from my experiment it will have to be bent well beyond for it to not spring right back.

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    cant you just send them back to the manufacturer for replacement?
    "No matter what you try and make in Russia, it always turns out like a Kalashnikov,”
    Vladimir Putin 2013

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    I would contact Tortort and see whats up. I'm sure the guy that made them would be the best place to start.

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    I have three of his receivers and not had that issue. They build up very nicely. I would contact him first before you do anything. He seems to be a stand up guy and supports his product. He also put out a measured drawing to complete these. I would ask him about that too and be sure to have the revised version as the first one had some issues if I remember correctly.

    I don't know if it will help you but if you have a Childer's template they work fine for a fcg layout guide as well.

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    Does the bolt & carrier operate properly in the rails with no binding etc?. I would be inclined to mod the receiver cover a tweak and go from there,.

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    I would cut through the ejector web first before doing too much.. one of mine had the slight warp (where lower rails stop towards rear) This kind of "relaxed" after cutting the web, and wasnt nearly as obvious.
    "Never thought I'd say this, but that's a real nice pair you got there Jeff." - Fiorentino

    WTB -

    (4) 68 dated Russian slings
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    After you have cut through the web try the carrier for fit , if it rubs and hangs up the carrier from sliding easily then you have to address the problem .I have straightened them using washers for spacers and vise grips and angle iron[polished so it will not mar the receiver].I put the grips on either end to hold the angle iron in place and just stacked the washers so there was enough room to squeeze the warp out . I also used a small piece of metal under the grip I was using to straighten with to distribute the pressure so I didn't get a distortion. Just go easy and pay attention to the rest of the receiver.Before I resort to straightening
    it I would consult with Tortort to see what he thought about it. I have straightened really bent receivers by just going slow and easy.

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    Just wanted to give an update. I got both receivers straight fairly easy. Hope to get on built up in the coming week. Thanks for the replies.
    22many, ford63man and Sunspot like this.

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    How did you end up fixing it? Mine's warped too, but I'm waiting on Tortort's directive before messing with it. Thanks!

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    I used a few different methods to straighten mine. I started out just using a large C-clamp and my 1 1/2 in thick shop table using the clamp to bend the receiver in. That worked to a degree but not to my satisfaction. I got Some 1/8" thick X 3/4" wide steel and cut some pieces .100th smaller than the inside dimensions of the receiver and one piece the correct width of the receiver. I used these pieces to support the area i did not want to over bend or stress to get the warp out. I also used some heat from a map gas torch. I did not heat the receiver red hot. This got most to all the warp out. I used a small rubber mallet to fine tune it with swift hard taps to adjust the straightness. I lapped the receiver on the top of my cast iron table saw top with some 150 grit sand paper.

    I wasn't going to work on these much until i got into my new shop I'm having built but the construction process has recently been delayed so for the past 3 days I've tinkered with one build during the evening hours. I thought building from a flat you had a lot of time in the receiver but these milled receivers will chew up some time. I am very happy with how these are turning out and will be purchasing more the next run tortort has. The warping from heat treatment is not really a big issue. It was fixed with relative ease. I was just very cautious this being my first milled builds to tackle.

    Im still looking for parts to complete the second one but the mix master is coming along nicely.

    Took some crappy pics just for reference


















    Receiver is dead nuts straight now
    Last edited by NXCHESTER; 10-06-2016 at 11:07 PM.
    Hueto, Brawny, Walleye and 1 others like this.

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    Thanks for that. The problem with mine is that the entire receiver is bowed. I played around with it on a press, but the spring back is crazy with this steel. I've got a spacer between the top rails and have the receiver spanning two steel blocks. I'll put my big boy pants on later today and hit it with a torch while having it over bent a little in the press.




    I did cut the web but it didn't seem to do much.

    BTW, your build looks great- Mine is essentially the same mutt.


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    What i have used to straighten flats after heat treating them they seem to warp like your receiver which is easier to correct at least on a sheet metal receiver. I use a block of hard wood like Hickory with the receiver laying on its side and put the block of wood on the top rails and use a mallet to straighten the rails. I work the whole length of the receiver. The wood will deform or split before marring or damaging the receiver.

    The rifle in the pics is a mix of Polish, Bulgarian, and Russian parts. I want the second build to be all russian but its not looking that way. What barrel are you using i got mine from AOA. I decided to go with the double hook trigger cut out on mine. Also i would like to add that CNC Warrior bullet guides will not work in these receivers or at least the two bullet guides i received are off. I had to use surplus bullet guides. My bullet guide once riveted in sat below the Left hand lower rail and the bolt would get locked up in battery. Just placing the bullet guide in the receiver loosely it looks fine but after i riveted it in it got sucked down and the bolt would catch on it. I didn't notice this until i had the barrel populate and headspace. I was pissed when i had to pull the barrel again and redo the bullet guide. You can't see it in the picture unfortunately that is the only pic i took of it before i found out it wasn't going to work.









    Last edited by NXCHESTER; 10-07-2016 at 02:26 PM.
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    I spent a bit of time playing around with it this morning and got it to an acceptable enough state. The ejector side rail to operator side rail dimensions were never an issue- The receiver was simply twisted, which caused it to bow to one side.

    I used a combo of a press and blocks to try to address the bow, but once it starts flexing, the mag well would start to distort. I used a spacer to block it out, but it still wanted to distort.

    I'm using a chromed AK-Builder barrel, and all of the RobertRTG NOS Polish milled parts I could get (top cover, bolt carrier, recoil assembly front sight, rear tang, EG muzzle nut), a mix of unknowns (rear sight block, HG retainer, gas block that I rust blued), and some Soviet parts (AKM trigger guard with NOS Polish milled catch, T3 selector from RussianSurplus), and a NOS Chinese cleaning rod, AK-Builder bullet guide.

    I've got a NOS set of wood that i bought and had sent directly to Z_Recto for him to apply the magic. He sent me this pic:


    Once I get the receiver squared away and manage not to screw up the cuts, I want to rust blue it to match everything else. It should be a righteous build.

    I'm debating rust bluing the barrel- I lightly polished out the black oxide finish and got it looking somewhat like a matter blue, so I keep debating it in my head if it's worth the trouble. I was able to get the Polish top cover to match by lightly buffing it out with fine steel wool.

    I'm also waiting for the 1/2" x 90 degree (w/slight radius)double angle cutter that I got for the selector notches. I played around with a few (3/4" and 1" 90 deg) that I found on Amazon, but they're not what I'm looking for. Here's what I came up with on a Yugo scrap. Keep in mind I'm doing this on a drill press.


    Your cuts look fantastic. What did you use?

    Thanks for your insight!

 

 
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