Underrib installation question

[rogerpjr]

This may be a silly question, but all my previous builds have been fullstocks and I've never had to to install an underrib on a halfstock. I'm going to be using four 5-40 screws to attach the rib to the barrel. What is the best way to drill the holes through the rib? Do I drill the #30 clearance hole first and then the #6 hole for the head of the screw or vice versa? Also, how do I get the hole for the screw head flat bottomed or do I not need to worry about it being flat?

[sz]

To get perfect alignment always drill your root hole through both piece at one time. Clamp the rib to the barrel tightly and drill the root hole in at least 2 places and I prefer 3.  Next tap those 3 holes. (I even run the tap through both as they are still clamped together.)

THEN remove the rib and drill it for clearance.

You need only drill and tap 2 or 3 as a start.  Install your screws.  When those 3 are holding the rib down it can't shift and then do 3 more. The more you do the more solid it gets.

[L. Akers]

There is no such thing as a silly or dumb question--only the answers are silly or dumb.  I drill the clearance hole for the screw head first, then a tap sized hole for the shank (to be opened to body size later).  Drilling the screw head hole first creates a lead for the following drill so they stay concentric.  I then use a mill bit to flatten the bottom of the screw head hole.  I do this on my drill press.  Lay the rib in position on the barrel and using ONE hole, run the tap drill down through the hole and spot the location on the barrel by creating a shallow hole.  Remove the rib and finish drilling and tapping the hole in the barrel.  Run a body size drill through the rib hole used to locate the hole just drilled in the barrel.  Attach the rib to the barrel using the screw for the purpose.  Now you can mark the remaining holes using the same method.

[JoeG]

You can make a bottoming  drill by grinding the tip off an extra or broken bit.
I make my bottom taps the same way

[D. Taylor Sapergia]

A tutorial would be useful here.

[Gaeckle]

The old timers used rivets to keep the rib on and I think they did in this fashion (could be wrong in my guessing though) The rib was clamped fast to the barrel, the appropriate size hole was drilled through the rib and into the barrel, the rib removed from the barrel, a nail or other piece of round stock was inserted into the hole in the barrel and it was then peened fast with a pointed punch. The rib was then set back on the barrel over the pins, the desired leangth was determined, the pins reduced to their correct size and the with the rib back on each pin was then peened by mushrooming the head to clamp the barrel fast.

When I look at old barrels with partial ribs attatched I see the remains of the pins with a multitude of punch marks around them....that's how I interpret the process.....could be wrong.

I solder the ribs on, for me that's easier, less work involved.

[flehto]

I drill the clearance holes in the  rib then clamp the rib to the bbl and "spot" for the  tap drill w/ the clearance drill. The rib is then removed and the tap drill is drilled to the proper depth  followed by a same dia. flat bottom drill. Each hole is then slightly ctsked....if needed.

Both the tap drill and flat bottom drill are used w/ a drill collar and I also use the lockable spindle  collar to ensure that the drill is at the right depth.

The first tap has much of the first lead threads ground off and the final tap is flat bottom to achieve as many threads as possible.  The ctbr for the heads is the last thing done.

Doubt if I'll do another Hawken, but if I did, I'd rivet the rib on...a lot less work.....Fred

[rogerpjr]

Never thought of the rivet idea. That is basically how I installed the staples for the barrel keys though.

[D. Taylor Sapergia]

I riveted the last rib to a Hawken barrel, and THAT is the way to go.  I did a short tutorial on that process a while back.

[D. Taylor Sapergia]

http://americanlongrifles.org/forum/index.php?topic=29600.0

Here's the short tutorial to which I referred.

[FALout]

I did my last half stock the way Taylor suggested, by riveting.  That is the only way to go, and as said is more authentic.  I was worried about maybe one of them not holding, but there was no issue.