The Rifle Shoppe Baker Rifle Part III

Measurement challenges, lugs, dovetails, sights, soldering ... .

So as noted; the barrel is actually a featureless tapered cylinder that presents some measurement challenges, mainly finding the absolute top and bottom center lines.  You can order the barrel from TRS with the dovetails already cut for you, this kit did not. Before starting to cut things up I decided to check with a few different gunsmiths to see how they locate things like scopes, sights etc.  Turns out on modern rifles you almost always have a receiver to use as a datum (starting) point. All this barrel has are the sides of the breech plug - not a lot to go on, but is enough.

What you need is a couple V-blocks, a couple 123-blocks, a machinists square, a height gague and some layout fluid (Dykem)


Baker Rifle

Find a resonably flat surface, setup the barrel in the V-blocks and use the machinists square against the sides of the breech plug lug rotating the barrel until the sides of the lug are perpendicular to your "reasonably" flat surface. That will align the centreline of the barrel perpendicular to your surface, you now have either the top or the bottom of the barrel facing straight up. Clamp down the V-blocks using a shim, brush some layout fluid on at the locations the dovetails will be, refer to the drawing and using a scribe mark the exact (!!!) locations of the dovetails along the barrel length.

Next; take the 123-blocks, one on either side of the barrel at the location of the dovetail, use a aliper to measure the distance between the two inner faces of the 123-blocks, divide that by 2, set your caliper to that number and scribe the top of the barrel using the inside face the 123-block as reference. Scribe another line on the top of the barrel from the second 123-block, if you made an error those lines will not be in the same place. Repeat that process for the remaining dovetails.

Baker Rifle

Now you have the locations and centers of each dovetail, but we need to know how deep the dovetails need to be.


Baker Rifle


Measure the thickness of the bases of your barrel lugs, sights etc - in my example all the barrel lugs were slightly different thicknesses but close enough that it really did not matter.  Now is the time to consider the taper of the barrel. your lugs and sights need to be paralell with the surface of the barrel.  Shim up one of the v-blocks so that the top (or bottom - whichever you decided to start with) of the barrel is paralell to your reasonably flat surface which you can check with your height gague.

Zero out your height gague at the chosen dovetails location, lock it down then lower the scribe bar until the indicator reads 0 minus the thickness of your lug or sight, whichever you happen to be working on. Lock the scribe bar and scribe a line on both sides of the barrel. You should now have a rectangular area sribed onto the barrel, this is marking the material you will remove for the dovetail.




FIRST: Zero your height gague for every dovetail AND check the barrel top is still paralell to your flat surface. My surface is my router table, reasonably flat, but has some fairly serious dips in it. That would have resulted in some dovetails being too deep or too shallow.  Setup and measure each dovetail individually.

SECOND: The base on the front sight is too thick for the location noted in the drawings. Measure it's thickness, the thickness of the barrel where it (the sight) will be located and file down the sight base until it is thin enough to give you a safe barrel thickness. If you try to cut the front sight dovetail "as-is" you will wind up with less than 0.020" barrel wall thickness.  Speaking of the front sight, check your references, the drawing not only puts it in the wrong location, but it also is not the correct sight!  I believe that the example TRS was working from probably had the original soldered on steel sight removed and an "improved" brass one installed further back.


With all your dovetail locations marked out you can either start cutting them or flip the barrel over and repeat the whole process for the remaining lugs. 

My suggestion is to do the sights first. If they are rotated to one side or the other you can still index that breech plug a bit to get them perfectly top -center. Then go back and do the under lugs, if they are off by a degree or two you will have challenges with the barrel keys but at least the issue won't be visible or have any real effect on overall function.


Cut the dovetails

Baker Rifle

Everyone is probably pretty familiar with cutting a dovetail by hand, so just the Coles Notes. (I think they are called Cliff Notes in the USA?)

  • Use a 3-square (triangular)  file to start the cuts for your hacksaw - not necessary, but it helps keep the saw from slipping, make sure these are just short of your scribe marks.
  • Use hacksaw with a fine (32 tooth) blade to cut down to your scribe marks, not right on the line, stop 0.010" or so short of your scribe marks.
  • Use a bastard file to get rid of all the material the hacksaw didn't remove - DON'T cut beyond your scribed lines.

Clean up the bottom of the notch and cut the dovetail under cuts using a 3-square with a safe edge (all the teeth ground off). Keep the file flat against the bottom of the notch and ensure you are not tipping it into the undercut.

Your lug (sight/whatever) does not or should not fit in the dovetail. You need to test fit and fine tune the dovetail with your safe-sided 3-square file until you can tap the lug (sight/whatever) in using a brass punch & hammer. Ideally the right side of the dovetail is slightly wider than the left so that whatever you set in there gets tighter as you drive it in.  That angle should be imperceptable less than one degree is just fine.


The bayonet lug

Baker Rifle

The bayonet lug is a fairly large chunk of metal that needs to be either silver soldered or brazed to the barrel.  I do not have an oxy/acetylene setup and didn't think I was going to have much success with a propane torch so I got myself a MAPP gas torch. A game changer for sure!

Clean up the bayonet lug to basically finished as it will be difficult to work on once soldered to the barrel.  Locate the centreline of the right side of the barrel using the same method that was used to locate the dovetail locations.  The customer did not buy the bayonet so it (the bayonet) couldn't really use that to locate the lug, if a bayonet shows up in the future the lug may need to be relocated, the pre-cut notches in the stock were used instead, not the best plan as the lug is about 1/8" too far forward.
File the concave surfaces of the lug contact points to match the contour of the barrel taking care not to remove too much from the front tab, if a bayonet ever shows up and that tab was filed down too much, the bayonet (24" long!) could obstruct the path of the bullet.  Tin the contact surfaces of the barrel and lug, clean up as much stray solder as possible as it will be difficult to clean up after the lug is attached.  Locate the lug on the barrel, clamp it with a spring clamp and solder it.  I was a little dubious about the strrength of silver solder for this application, but the joint is remarkably strong.


The last things that need to be done with/to the barrel are to drill the hole for the sling swivel and to drill the touch hole. You will drill the sling swivel hole after inletting your new lugs into the stock and the touch hole should be done last. The touch hole should only be drilled after  the lock and side plate are fully inlet and any adjustments to their positions are made.  If you drill the hole now and your lock moves 1/16" for some reason your Baker Rifle may have some ignition problems.





Part Four: Coming soon.