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Author Topic: Bent screw  (Read 1184 times)

gundog10

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Bent screw
« on: January 22, 2016, 10:22:33 AM »

I just completed my first 80% lower and while not perfect it looks pretty darn good (kennel blindness).  I used the Modulus arms HD jig and it worked very well but as I was taking the jig apart I noticed the bottom right hand bolt had bent and I needed to cut it off in order to completely disassemble it.  Has anyone run into this issue and NO, I did not torque the vise down hard, just good and snug.  I have started on my second lower and am using the 80% easy jig and I tightened the vise down tight and as the bolt that goes in the bottom right hand side is 3 times the size no bend.  Just wondering and I am off to the hardware store for a new (hopefully grade 8) bolt.     
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7.62X39

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Re: Bent screw
« Reply #1 on: January 22, 2016, 10:34:58 AM »

Since you said that you did not have the vise cranked down too tight there is only one other possibility. The two side plates were not parallel to one another.

After you loosely attach the side plates to the top plate, squeeze the side plates against the receiver then snug up the bolts that attach the side plates to the top plate. Check that the plates are parallel then install the long bolt.

If all that is done properly, you would have to crush the receiver in order to bend that long bolt. There is nothing wrong with the strength of that bolt as long as it is installed correctly.
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gundog10

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Re: Bent screw
« Reply #2 on: January 22, 2016, 02:42:46 PM »

That is most likely what happened.  I read the instructions but must have not caught the tightening sequence.  Thanks for the information.   
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