laying out a pattern

[chuck c.]

I'm trying to lay out a thin plywood pattern for my first attempt at building from a blank, and I'm trying to follow the instructions for doing so in "The Gunsmith of Grenville County". These instruction seem to work fine if you're working with a straight barrel. The book states to make the web 3/16 thick at the muzzle and 1/8 thick at the breech. If I'm understanding things correctly a thin web makes for an overall slimmer rifle which is what I'm after. When you establish this line on the profile of a swamped barrel the web in the waist of the barrel is pretty thick. I'm assuming this can't be avoided. The problem I'm having is when you add in the fact that the muzzle is smaller than the breech and the line for the web is not parallel from breech to muzzle, each line drawn afterwards progressively tappers towards the muzzle. I want the upper forestock to be 7/8 in height which it is at the ramrod entry point but as I progresses towards the muzzle it tapers to 3/4". I'm thinking that the solution is to take all measurements from the centerline of the side flat of the barrel, but I haven't been able to accomplish this either. Am I over complicating this, or missing something, or just dense?

[smallpatch]

Chuck,

You're not missing anything, and at this point, I don't think you CAN overthink what you're doing.  Everything you do at this point, will determine the architecture of the finished gun.

With that being said..... forget about the swamp.  A straight line from the bottom of the breech flat to the bottom of the muzzle flat, is the line to use for your lay out.  No one will know that the web is thicker in the waist of the barrel.  The forearm will be nice and slim and straight.

[Dphariss]

I'm trying to lay out a thin plywood pattern for my first attempt at building from a blank, and I'm trying to follow the instructions for doing so in "The Gunsmith of Grenville County". These instruction seem to work fine if you're working with a straight barrel. The book states to make the web 3/16 thick at the muzzle and 1/8 thick at the breech. If I'm understanding things correctly a thin web makes for an overall slimmer rifle which is what I'm after. When you establish this line on the profile of a swamped barrel the web in the waist of the barrel is pretty thick. I'm assuming this can't be avoided. The problem I'm having is when you add in the fact that the muzzle is smaller than the breech and the line for the web is not parallel from breech to muzzle, each line drawn afterwards progressively tappers towards the muzzle. I want the upper forestock to be 7/8 in height which it is at the ramrod entry point but as I progresses towards the muzzle it tapers to 3/4". I'm thinking that the solution is to take all measurements from the centerline of the side flat of the barrel, but I haven't been able to accomplish this either. Am I over complicating this, or missing something, or just dense?

Inlet the barrel with the underlugs and pins/keys and the tang screw run it to a nut and washer. Now the the barrel fixed  cut the rod groove to make the web you need. THIS is what sets the  depth of the forestock.

You cannot swamp the rod groove since you need to use it to guide the hole drill and take a rod in and out of it when finished.
Drilling the rod hole sets the rest of this so cutting the groove a little deeper toward the breech will angle the rod hole up toward the barrel.
I do the barrel, then the rod channel and then the hole THEN I know how deep the stock will be at the trigger.
You can saw the forestock a little deeper since the rod groove sets the finished stock then take it down to make the rod groove look right. Doing this also can allow a little extra wood just incase the drill cuts lower than planed.
Before you get too into this 1/8" web at the breech you better plan for lock screws.

Dan

[Rich]

I use a 1/8 thick web at both the Muzzle and the breach and do not consider the variations caused by the swamp of the barrel in the middle. Small Patch is absolutly correct in pointing out that you can't overthink at this point. Lay out the ramrod pipes, barrel pins, lock, vent and trigger and anything else you can think of. You're also on the right track with a plywood pattern. On my first rifle, I cut out a paper pattern. It was amazing how much it moved around when transfering it to the blank. I caught it before cutting. Now, I draw the plan on paper and trace it onto 3M transparancies for Copiers. They are stiff enough to keep their shape after the shape is cut out. Since they are clear, I can lay it on the blank whenever I want to mark where various features will be.

[chuck c.]

Thanks for the advice guys. The advice along with all the planning is giving me a much better understanding of what I need to do!

[Stophel]

When I do my patterns, I have my drawing on paper first.  I pretend that the barrel is straight.  That's the only way I can get things consistently straight and in order as far as drop at the butt, comb, etc. is concerned.  In essence, everything is indexed off the centerline of the barrel, up and down.

Anyway, I transfer the drawing to a piece of luan (sometimes, if I think I'm going to do more than one of this same design), again, pretending that the barrel is straight, just to give me a good straight edge on the top parallel to the bore.  I don't worry about figuring the fore end yet, I just get it roughly to shape and oversize, I just need something for proper positioning on the blank at this point.  When I have the pattern where I want it, I trace it off, then measure down from the top-of-the-barrel line half the thickness of the barrel and make my centerline and then cut off this slab of wood to begin inletting the barrel.  Once I get the barrel in, then I worry about the finer points of positioning the ramrod. 

Normally, I do 1/8" between the rod and barrel at both the breech and the muzzle, but with some barrels that have relatively small muzzles, I will do more there.  Generally, I want the rod to NOT be parallel with the bore, but ever so slightly tapered towards the muzzle...definitely never the other way though!  Parralel is OK, depending upon just what barrel you're working with, but often, it makes the front end look too thick.  I guess it depends upon just what you're doing.  Some rifles should done with very straight fore ends, whereas others (primarliy earlier ones) can have taper in the fore end.

I draw it out on the blank, basically drawing the fore end around where the rod goes, and then just cut it out and drill it.  I make sure that my pattern for the butt is still right in relation to the barrel, and adjust as necessary (I often inlet the barrel deeper than I need to, so I then need to move the butt pattern to compensate) and cut it out.