Wood underrib attachment questions

[Ky-Flinter]

I'm building a half stock rifle with a 1" x 36" Getz .54 barrel and a cherry underrib.  I'm planning on attaching it with slotted flat head screws for ease of removal, if things don't work out.  The barrel wall thickness is approx. .0205", so I figured to keep the screw hole depth to 0.100".  The rib is 21-5/8" long.

So here's the questions.....

How many screws should I use?  Will 4 be ok or do I need 5?

What thread pitch should I use?  

I have scrounged up 4 5x40 pitch screws, but have plenty of 6x32's (which have the advantage of a little larger diameter head).  

Thoughts?  Thanks.

-Ron

[rich pierce]

I think most originals used underlugs and pins.  I hate drilling into a barrel wall.  I would fasten in 3 places- ends and middle.  How are the screw heads going to work with the ramrod?  OK?

[Dave Dolliver]

I have made 3 wood under rib fowlers.  The barrels were too thin to tap for screws.  I soldered 1/8 x 3/16 lugs to the bottom of the barrel for 1/16 steel pins to hold the rib on.

On octagon half stock rifle barrels I have used screws.  I use 6 screws: 1 at the nose and 1 at the tail, and 1 on each side of the 2 ram rod pipes.  I use 6-48 thread Weaver oval head screws from Brownell's and couter sink the heads with a piloted, shaped counterbore from Brownell's.

Most original metal ribs were soldered to the barrel.  I did this once, also, on a piece for a museum where something historically correct was desired.  I like to screw on my own ribs so that in the future, if muzzle work is needed, I can remove the rib and fit the barrel thru the headstock of my lathe.  It won't take both barrel and rib as an assembly.

Dave Dolliver

[Robby]

KyFlinter, I've done three half stocks with wooden ribs. I dovetailed studs into the barrel. The spacing of the studs was figured by subtracting 1" from the front and rear if the rib and then dividing the remaining space to where the studs would not be more than 3" apart. Just my opinion, but I don't think using screws is the way to go.
Robby

[California Kid]

If you are building a New England rifle, all the ones I have seen had the wooden rib pinned. I think much safer to do than drilling the barrel

[Ky-Flinter]

Thanks all for the comments and suggestions.  Any additional new ideas will be welcomed.

..... How are the screw heads going to work with the ramrod?  OK?

Yes, I had planned to countersink the screw heads just below the plane of the ramrod groove.

Dave,
Thanks for the suggestion of 6x48 screws.  I bet they work great with a steel rib but I think I need more head diameter than the Weaver's to hold the wood better.  I take it from your suggestion of 6x48 that more is better on the thread pitch question.  I.E. 6x32 is too coarse?

Robby,
Dovetailed studs?  Like a regular barrel underlug, pinned horizontally thru the rib?  "Stud" makes me think of a vertical pin thru the wood into the RR groove and then peened.  Which?

CK,
I'm not trying to replicate any particular style, although it has some Plains features and other stuff I just wanted to try. 

Thanks again,
Ron

[Robby]

KyFlinter, I don't have any of them here or I would post a picture, that is much easier for me, and probably way more clear than I can explain . I used brass, and yes they are inserted into dovetails , just like barrel lugs. The stud is filed out, or, I suppose you could silver solder them to the dovetail piece, and clean them up with a file. The height of the stud is just below the bottom of the R/R groove, though they sometimes break through, no problem, just file to match the groove, or in my case, the groove is filed in after attachment because they were swamped barrels. Little mortises are chiseled out of the rib and then pinned with 1/16" diameter weld rod.
Just remembered, I did do a fourth half stock with a straight barrel and made the studs from brass and filed a little nub on it, drilled a shallow hole into the barrel and soldered it direct to the barrel. The picture is of that gun. These ribs are a lot stronger than you might imagine. Hope this helps
Robby

[Dave Dolliver]

Iuse 6-48 thread screws onl because there is limited thickness to tap into and 48 threads/inch will give me a couple more threads than 6-32 in the same depth hole.  The Weaver oval screws have a slightly smaller head dia and fit into the rib groove better; I also think they are of slightly better material.

dave Dolliver