How I cut barrel dovetails by hand

[Ky-Flinter]

One of my current projects is a pistol with a .50 caliber tapered octagon barrel.  The barrel wall thickness at the front lug is .1525” so the base of the lug must be thin. I considered soldering the lug directly on to the barrel flat but the web between the barrel and the ramrod groove is pretty thin, and I didn’t want the lug base taking up valuable real estate where my barrel key will go thru.

Here’s how I set up and cut dovetails by hand.  First file the base of the lug down.  I started with a lug like the one on the right.  The one on the left is thinned down to .034”.



I trued up the edge of a piece of brass flat stock and I attach it to my hacksaw blade with these little brass thumb screw gizmo’s.  I got these in a box of tools at an estate sale.  I think they can be bought at woodworking suppliers.  I left about .027” of the blade edge exposed to control the depth of my cuts.  Hacksaw blade edges aren't always perfectly straight, so check the amount of blade exposed in several places and make the maximum spot the depth you want to cut.





Mark the lug location on the bottom barrel flat.  (Don't ask me why I stress that.)  The marks should be a little narrower than the top of the dovetail on the lug to allow for cleaning up and filing in the undercut for the dovetails.  Saw away, but check the blade stop frequently to make sure it hasn’t slipped.



After you have sawn the slots, knock the slivers off with a cold chisel.



Carefully file off what’s left of the slivers so the dovetail base is smooth and level.  Go slow and check often, so you don't go too deep.



Then use a tri-cornered file with the teeth grounded off of one flat to file in the corners of the dovetail.  Check the fit often until the lug can be tapped into place.  Be careful the dovetail slot isn’t too tight.  If a lot of force is needed to install the lug, the thin base will bend.



You can use a punch to dimple the edges of the dovetail to lock the lug in place.

This is just how I do it.  They aren't ever perfect, but they work.  Any suggestions for improving my method are most welcome.

-Ron

[Ed Wenger]

That's a good idea/technique with the brass stop, and new to me.  If you make the loops (lugs) out of .040 brass, you wouldn't have to file the store bought ones...  Thanks for sharing!


            Ed

[jamesthomas]

 It looks good!, I think that's how most folks make their dovetails.

[J. Talbert]

Ron,

Nice job!
I like your little depth stop gizmo.  But since I never thought of that, and now I'm used to doing it my way, I just count my strokes.  It doesn't take many, and the depth is pretty consistent with an equal number of strokes.

Jeff

[Lucky R A]

   Make your dovetail about 1/8 in. undersize, then lift each end of the dovetail with a cold chisel until your underlug will slide in.  Carefully hammer or punch down the ends totally locking the underlug into place.  much simpler, faster and no files involved---and it is P.C.

Ron

[WadePatton]

Like the stop.  Good pics and write up, thanks for taking the time.

Never thought about making my own hacksaw frame until i looked at your hacksaw.  Yes, i distract easily.

[oldfox]

Great tutorial!  BTW, those "little brass thumb screw gizmo’s" are stair points for a framing square.  They are used in laying out a stair stringer..

[bob in the woods]

Lifting the ends of the cut out with a cold chisel [ I made one especially shaped for this task] works well, and is my normal way of installing lugs and sights, but…one time , on one barrel,  the lifted portions simply broke off . I can't remember the barrel maker, but it was a real pain to draw file, and seemed to have a brittle outer surface.  I'm not sure why. I've not run into that problem again since then.

[Ky-Flinter]

Jerry,
Thanks for letting me know the correct name for the "gizmo's".

Bob,
I had one do that to me also, so I'll just file.  I'm in no hurry.  Some of the guys know how long I've been working on a pistol to surround this tapered barrel.

-Ron

[Pete G.]

I don't need to ask "Why" you marked the bottom flat so prominently.
That moment that you realize that you have cut three perfect dovetails in the side of your barrel is indescribable.

[t.caster]

I do it the same way, and now I will incorporate the saw stop idea too! I have a couple stair points in my toolbox already. Slick idea! Thanks!

[Ben Quearry]

I've been locking at a pair of star points on a shelf near my stocking bench for some time, I knew there was some reason I left them there! A great idea, I can think of several other uses for it too. thanks for the tip

[Dr. Tim-Boone]

I just bought: 'Johnson Level & Tool 405 Contractor Brass Stair / Square Gauges, 2-Pack' by Johnson Level & Tool
www.amazon.com
Brass Stair/Square Gauge Set - 2/Card Super for repete angle cuts to make your stairs and rafters straight and true


$5.99

[Frank]

I just bought: 'Johnson Level & Tool 405 Contractor Brass Stair / Square Gauges, 2-Pack' by Johnson Level & Tool
www.amazon.com
Brass Stair/Square Gauge Set - 2/Card Super for repete angle cuts to make your stairs and rafters straight and true


$5.99

Excellent, just bought 2.