Inlet a swamped barrel with guide rails

[galamb]

Just starting a build and decided to document one technique for inletting a swamped barrel. The instructions come from "The Gunsmith of Grenville County".

The basic technique is that you fasten rails in the shape of the side flats of the barrel to use as cutting guides down to the depth of the bottom of the side flats. This will (should) give you a nice tight inlet against the side flats of a swamped barrel and can be done at your own bench with minimal tools.

I am aware there are a couple variations on this technique but am following the book. The accompanying pics/notes may help anyone else trying to follow the method in the book.

The barrel being inlet is a 42" Rice Southern Classic 45 cal (The SC has it's own unique weight and profile - called an A-wt it's actually in between an A and a B).

I will do this in a few updates since I figure this will take me 3 or 4 days to complete.

The method described inlets the barrel without cutting down the top to near it's finished (height), normally near the mid-point of the side flat. Additionally, I have left an extra 1/16" on the top of the blank because you know you will jigger something up and a little insurance is nice.

And finally, yes, the barrel is quite a bit closer to the cheek side of the blank - done on purpose to allow for the cast-off at my length of pull (14 1/2").

Anyhow, enough babbling on my part here is step 1.

(this was about 4 hours work (including coffee/smoke/pic breaks) to cut the channel, drill/counter-sink the rails, and then install the rails with about 40 screws in piloted holes)

More to come...

 

[fusil de chase]

Graham,

Thanks for posting, I hope you document more of the build.

 

[Stophel]

Seems like a lot of work for dubious advantage.

I've gotten to where I can inlet a rifle barrel by hand in about 4 hours. No rails necessary. The rest of the gun might take me forever though! :haha:

 

[galamb]

I was intrigued by the process so decided to try it for myself.

Yes, it is more work than simply scribing a line and going at it (mostly with my router) but I am curious to see the end product.

Additionally, there are many who figure inletting a swamp is too difficult, so also attempting to show it can be done easily - with effort and work yes, but not overly difficult.

When it's done I'll decide for myself if it was worth the extra effort - my time is "free" when I'm building for myself and the alternative was shoveling snow :grin:

 

[galamb]

Graham,

Thanks for posting, I hope you document more of the build.

Yes, I think I'm going to document this build fairly well and plan on posting a lot of it up.

After years of hunting Bambi with a 36" barreled/40 cal I have decided to "drastically" increase my firepower all the way up to 45 :rotf:

I have spent almost a year studying and patterning out the rifle, a kinda collage of Christian Hawken's work over a 40 year period all rolled into one rifle - ok, a "fantasy gun", but think it will be sweeeet.

 

[kaintuck]

Did you use a powered router?
And what bit for which cut?
And when making the bottom cuts, if using a powered router, how is the waist area left higher than the ends? Could we put shims under the side guides?

Very interesting...... :hmm:
Seen it here before, but my questions nag me.....

 

[zimmerstutzen]

I have done something similar, but used sturdy 2 inch angle iron clamped to the sides of the stock blank. using shims where necessary to keep the angle iron at right angles and equidistant. Then I mounted a router guide on each side of the router so the router could not accidentally bounce out of where it was suppose to be cutting. I cut the channel for the bottom flat fist and then the sides. It worked quite well to cut the barrel channel for a straight barrel.

 

[galamb]

I only used the router to take out enough of a "straight" channel to get the barrel to sit in - so just two passes with 3/8" wide x 3/8" deep rabbet bit (overlapped a bit so I didn't exceed the 3/4" width of the waist.

The next step I will cut out down as far as the side flats with a Japanese saw using the rails a guides for the outside (flats) - so just the saw blade width down right where the guides are(blade marked for depth).

Will start out cutting down to the minimum depth over the entire barrel length - so the bottom of the side flats of the waist area, then chisel out which will once again leave a channel of "equal depth" from breech to muzzle, only the sides will be "to shape" - then with a bit of fiddling cut the depth to the breech and muzzle.

Once that is done, then the bottom three flats are chisel cut (the bottom and two lower oblique).

Alternately, the bottom can simply be gouged out with a round nose chisel (which was the method used on many original long rifles - it was mostly English rifles where you find the bottom three flats actually cut in the way most contemporary builders do it.

I bed all my barrels with marine epoxy, mostly to strengthen the web/forestock so I generally don't go for the "fit's like a glove" inlet on the bottom three flats, but will see how this one goes as I proceed - I kinda want a good collection of pics showing (proper) building technique - I have never really taken photo's of my builds before.

Pics will probably illustrate my (poor) explanation above - at least it should make sense of what I was trying to say. Hope to get at it tonight and have the pics up shortly there-after.

(I cheated and used a power router to cut the initial channel, but could have used a chisel. This method is meant for the guy/gal who only has chisels available for inletting a swamped barrel. There was a fair bit of time spent setting up the rails but on a subsequent barrel I would easily save an hour of so - just hog out a channel, clamp in the barrel and then fire the screws in the rails)

 

[galamb]

Now that the rails are installed I will move on to Step 2.

This involves sawing down to the lower edge of the side flats with a saw, using the rails as guides.

I will only saw as far as the “shallowest” side flat, which is the one at the waist. So first you have to determine where that is in relation to the top of the stock.

With a swamped barrel you really don’t have a “straight line” anywhere. The one consistent point is the center of the bore which is what you want to keep straight/level in the stock.

In this case the breech of the barrel is 15/16” ATF. I left an extra 1/16” on the stock for “fudge factor”, so the maximum inlet depth at the breech end is 1” ”“ this means the center of the bore is ½” from the top of my stock.

So, I mark the lock side of the stock at ½” at both the breech and muzzle ends of the stock ”“ this is my “level” center of the bore line.

You then place the barrel on the stock and “eyeball” the center of the bore to the two marks you placed there ½” down.

With the barrel set I place a pencil mark at the bottom of the side flat at both the breech and the muzzle. Those two marks indicate the bottom of the side flat at the extreme ends of the barrel. I then moved the bottom of the barrel to line up with the (side flat) marks and used the barrels profile to draw a pattern line defining the bottom of the side flats.

With it marked it’s off to the bench.

I started out using a Japanese pull saw but found it flimsy and it bound up rather quickly so I switched to a Dovetail saw. Still not great but could get down about 1/8” before it bound up.

The idea is you saw down to “define” the outside edge so that when you go at it with a chisel you don’t go too far ”“ the cut is your “stop point”.
After 2 hours I got about half the channel cut out down to the bottom of the side flats ”“ enough for tonight.

This “works” but I think I will stick with my router then chisel work on future attempts. If you don’t have a router this has merits, but is far more “tedious” to say the least. I will continue with this since it’s started now but will file this in the “tried box” when done.

Anyhow, here are a few pics

More to come...

 

[shguns]

looking good!
I think I would countersink those screw heads below flush. If not I'm sure I'd find a way to cut myself on one and leave red DNA allover my curly maple :cursing:

 

[galamb]

Ok, so 11 1/2 "shop hours" later, the barrel is inlet.

I liked the rails but found it tedious and time consuming using a saw/chisels.

I will modify the procedure to use them with my trim router and a template guide/straight cutter next time around.

This method DID leave a very nice/tight inlet so it is a very viable option for someone wanting to inlet a barrel with a minimal "tool box" using hand tools.

Ok, I "cheated" and used a router to hog out the original channel needed to seat the barrel enough to affix the rails, but that could have been done with a chisel just as well.

Anyhow 11 1/2 hours of my time is a lot cheaper than packing up the blank/barrel, paying the shipping to someone who can inlet it for me, pay their fees then pay the shipping to have it returned.

You can decide for yourself what your time is worth.

So here's what I got for my time:

 

[kaintuck]

Nice job, and thank you for the photos....time well spent doing a great job!

Now the lip urges need to be placed and inletted... :grin: