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1/14/2010 8:04:14 PM EDT
I'm installing a Jard trigger for my Bohica that I'm building.  My lower receiver, a Doublestar, doesn't have the threads for the handgrip screw tapped all the way through.  The instructions for the Jard say that it may require further tapping.  How do I do that?
1/14/2010 8:18:53 PM EDT
[#1]
A standard 1/4 20 tap from any hardware store.  You can buy a tap handle, but since the hole is mostly tapped, you could easily turn it with a pair of pliers.  Screw it in till it starts to bite, then add a couple drops of oil and turn 1/2 turn, then back up 1/4.  Do this over and over, adding oil every couple of 1/2 turns until you have tapped the hole all the way thru (you will stop having resistance when you turn the tap in on successive 1/2 turns).  The backing up breaks off the chip that the downward 1/2 turn cut.  The oil keeps the teeth lubed, and floats the chips out of the way.  At the end, since this is a thru hole, just keep turning the tap until it exits inside the receiver.  Ordinary oil will work in this case, but normally a special tapping fluid would be used.

Please correct this if anything needs it, but this method works for me.
1/15/2010 1:44:37 AM EDT
[#2]
the pistol grip screw is 1/4x28
1/15/2010 5:12:50 AM EDT
[#3]
Quoted:
the pistol grip screw is 1/4x28


Thanks.  That would have been bad.
1/15/2010 2:35:46 PM EDT
[#4]
I found a guy here in Alamogordo who makes muzzle breaks.  He's going to tap it for me for a minimal price.
1/15/2010 7:11:40 PM EDT
[#5]
Quoted:
A standard 1/4 20 tap from any hardware store.  You can buy a tap handle, but since the hole is mostly tapped, you could easily turn it with a pair of pliers.  Screw it in till it starts to bite, then add a couple drops of oil and turn 1/2 turn, then back up 1/4.  Do this over and over, adding oil every couple of 1/2 turns until you have tapped the hole all the way thru (you will stop having resistance when you turn the tap in on successive 1/2 turns).  The backing up breaks off the chip that the downward 1/2 turn cut.  The oil keeps the teeth lubed, and floats the chips out of the way.  At the end, since this is a thru hole, just keep turning the tap until it exits inside the receiver.  Ordinary oil will work in this case, but normally a special tapping fluid would be used.

Please correct this if anything needs it, but this method works for me.



Used a cheapie 1/4" x 28 Harbor Freight tap.  Worked fine when I installed the JARD for my ALS.

-David
1/20/2010 8:54:04 PM EDT
[#6]
All,
Thanks for the inputs.  I actually found a guy here in Alamogordo who is a machinist and builds muzzle breaks.  He tapped the thread for $10 then we sat around for 3 hours and he talked about groundhog hunting.  On the downside, he was helping me install the trigger and it was missing the disconnector, the disconnector spring, and one of those #40 screws depicted on the instructions.
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