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12/4/2011 6:23:24 AM EDT
I'm going to do the trigger set screw mod.  Trigger work doesn't scare me, I've done a bunch of 10/22s.  Anyhow, I always double an triple check that what I'm doing will be safe.  I've read the pinned thread 100 times.  The set screw use was a 1/4-28X1/4.  In my research I've read the Junk Yard Genius web page.  That site calls for a 1/4-20X1/4 set screw.  I do not want to mis/cross thread my lower.  So, what is the correct threading?  20 or 28 threads per inch?

Thanks
12/4/2011 6:32:25 AM EDT
[#1]
1/4-28


12/4/2011 7:12:52 AM EDT
[#2]
Opps.
12/4/2011 7:13:08 AM EDT
[#3]
Never trust the internet.....it truly is 1/4-28.  LOL.

Suggest running the tap all the way into the lower to assure the hole is fully tapped.  Some manufacturers don't tap this hole all the way through. You want to make sure that about 1/16 - 3/32 of the set screw makes it through the floor of your receiver without binding.  Also suggest using a very small amount of blue Loctite (do not use red) to keep the newly installed set screw in place during firing.  Once you get the takeup/sear engagement properly set, if your safety won't engage with the hammer cocked, you may have to grind a small amout off the top of the rear portion of the trigger to regain the proper clearance.

This is a good , cheap mod that improves overall trigger feel.
12/4/2011 10:24:26 AM EDT
[#4]
Thanks I had a feeling it was the 28.  Someone here would have flagged that mistake in the pinned thread.  

12/4/2011 8:09:47 PM EDT
[#5]
Quoted:
Thanks I had a feeling it was the 28.  Someone here would have flagged that mistake in the pinned thread.  



If I had driven a 1/4x28 tap that deep in a 1/4x20 thread in my lower reciever and then posted it as gospel, I'd not only deserve the flag, but a gunshot to the dome.

It's unfortunate that somewhere out there bad info is posted, but that's why I try to include pics, less chance of a typo that way (it is not a coinsidence that the tap is turned so that you can read it in the pic and the set screw is sitting on the package with a clearly legible lable).

12/5/2011 7:51:49 AM EDT
[#6]
That's why I alway double check any work I do.  The internet is full of mistakes just like this.  I can only imagine what a steel set screw would have done to the aluminum threads.
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