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9/22/2017 12:11:25 AM
Posted: 3/18/2002 10:35:03 AM EDT
First purchase of an AR.

I want to put a bipod on the free float tube but have never done this before. The directions which came with the stud seem too easy: Spot the hole with a center punch and drill using a #21 bit. Tap the hole going perpendicular to the free float tube, oiling the tap for a smooth cut. Screw stud into tapped hole. Snug down. Mount bipod on stud.

The length of the stud I have is 2-3 times the thickness of the free float tube. The neck of the stud has no threads.

I know this is a stupid question but would appreciate any insight on how to do this correctly.
Link Posted: 3/18/2002 11:02:36 AM EDT
I installed my stud (supplied by DMPS) onto my DPMS free float tube by simply drilling through the tube, inserting the stud, and tightening the DPMS supplied nut to the back of stud. (Much easier said than done - one of those "you'll need three hands kind of jobs". Needle nosed locking pliers saved the day here. Also a good spot of loctite to the stud threads. Did your stud come with a jam nut? If not, you can get one and thread and lock it onto your stud or per your directions tap your drill hole to the correct thread size and simply tighten your stud that way directly into the tube itself. Emerald, I'm sure opinions will abound here - keep checking back.

Good Luck - Hardwood
Link Posted: 3/18/2002 11:54:30 AM EDT
I spoke with the mechanical engineers at work and they strongly recommend you DON'T tap the tube directly. You only end up with 3 threads, as I recall.

The material isn't thick enough to reliably hold the stud. Even 1/4" thick aluminum isn't enough, per the books.

I talked with Bushmaster and they recommend using the Harris #5 adapter kit, which allows you to insert a studplate inside the handguard with steel threads of adequate length.
Link Posted: 3/18/2002 2:48:03 PM EDT
I've always just used a nut on the inside of the handguard. Getting the nut on is always a royal pain. I have also had the unthreaded part of the stud still be too long to tighten up the nut properly. I have either extended the threads on the stud or used a washer. Another PITA when you finally get the nut on the stud and it won't tighten all the way down. Good luck. Watch-Six
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