How Flat is Flat...

[fishmusic]

I am building my first rifle from a parts set and a blank stock (grade 3 maple). In the end it will hopefully look like a .45 cal. Jacob Dickert Early Lancaster. I had the stock cut to rough shape by a cabinet maker just around the corner and am rasping the area for the barrel channel flat and square. Just how flat and square is it supposed to be? I am thinking that I if I can get it to .010 inched flat and square then I am good. I have heard you shouldn't be able to see light when I put a straight edge on it. What say you more experienced builders? I am using hand tools but I do have a router if I really need it.

 

[Larry (Omaha)]

I am building my first rifle from a parts set and a blank stock (grade 3 maple). In the end it will hopefully look like a .45 cal. Jacob Dickert Early Lancaster. I had the stock cut to rough shape by a cabinet maker just around the corner and am rasping the area for the barrel channel flat and square. Just how flat and square is it supposed to be? I am thinking that I if I can get it to .010 inched flat and square then I am good. I have heard you shouldn't be able to see light when I put a straight edge on it. What say you more experienced builders? I am using hand tools but I do have a router if I really need it.

You are using the wrong tool. Use a carpenter plane and or a machine jointer. When a straight edge shows the work is parallel it is good.
Throw the rasp back in the drawer for now.
Larry

 

[waksupi]

Tip for the shop. Leave about 1/8" extra wood on the top edge until you get the barrel inlet. That will protect the edge from tools and dings. Rookies tend to keep taking wood off the top of the inlet from false readings from the inletting black, resulting in a wallowed out barrel channel. Once the barrel starts to drop in to the side flats, pretty much keep your tools off the side of the inlet, and concentrate on the bottom flats. Once your barrel is set in place and pinned, is the time to straighten up that top edge.

 

[Phil Coffins]

The top should be square with the sides, that makes the other steps easier. Flat and straight also helps a lot. As flat and straight as you can get it will allow you to know where to go with your inlets and drilled holes. I use a router to hog out barrel channels then do the final inletting with chisel and scrapers. Leaving the wood full height when routing then lower the top edge before final inletting.
Is the barrel swamped?

 

[doubleset]

I use a router to hog out barrel channels ...

Speaking from unfortunate experience many years ago, this is a dark path for the inexperienced to tread. Even now I would avoid it. I might set things up at some early point in shaping the stock to use a router table -- which would give me a lot more control. But a handheld router can eat your project in a moment if you aren't really experienced and cautious with it, and have it very carefully set up to prevent wandering and other more violent things routers like to do.

 

[The Crisco Kid]

The top should be flat and square with one side. I like the right side but it doesn't matter. The cabinet maker probably has a jointer which will do this in a few seconds. Or as mentioned use a plane and straight edge. A 4' level makes a good straight edge.
If you have a blank that is not curved to one side or the other it is a rare one. A jointer will help here too. You'll need to establish a straight center line along both the top and bottom of the blank. Only one side needs to be straight with the center line. Center line may not be the correct term since it doesn't need to be in the center of the blank. It may even be set off to one side to allow enough wood for a cheek piece. If you don't take the time to get this center line established and maintained you'll be fighting alignment problems forever. You'll have it a lot easier to get the buttplate, trigger guard, ramrod groove, etc. straight and lined up top and bottom. Building from a blank is like building a house, get the foundation right and the rest is a whole lot easier.

 

[Phil Coffins]

Yes, the router can and will turn on you very quickly, more then most other power tools. I use angle iron and clamps to limit its possible wandering. I also do the groove for the ram rod after the barrel is in place. The key to any build is planning and careful lay out. Those lay out lines and/or center lines will save you a lot of grief.

 

[doubleset]

@Phil Coffins:

Off topic, but have you ever used a router on hickory? Hickory eats routers for breakfast. One of the scariest experiences I've ever had with a power tool.

 

[fishmusic]

I appreciate all the input I have been getting, thanks fellas. Right now the top is flat to within .025 inches. It's square to that from the right side. The right side came smooth and flat (I checked with my 4' level). I will be inletting a 44" swamped barrel. Some of the cuts from the bandsaw are pretty rough but I have allowed for that by tracing a 1/16" larger than the profile and having the guy cut is a 1/16" outside of that.

I don't have access to the tools you mention. I don't want to send this to a jointer for fear that it will take off too much wood. Decent planes are expensive and my budget is limited so I don't have one. Feeler gauges I have and a decent machinist's square. So my question still stands: Is .01" flat enough and square enough? That's less than a 1/64" which is usually the tolerance woodworkers build to. Attached is a picture of what I am doing for reference.

 

[deerstalkert]

Yes, the router can and will turn on you very quickly, more then most other power tools. I use angle iron and clamps to limit its possible wandering. I also do the groove for the ram rod after the barrel is in place. The key to any build is planning and careful lay out. Those lay out lines and/or center lines will save you a lot of grief.

Phil never mind! my two brain cells got together and answered the question i had about your process! wish they were better acquainted!

 

[The Crisco Kid]

If someone can see .010" out of square and flat on a gunstock they have better eyes than I do!

 

[deerstalkert]

the flatter and squarer the better for laying out your lines, though you can draw one witness line down the side of the blank and pull all measurements off that.

 

[Phil Coffins]

I feel that your .010” will work. Next build consider making one side flat and then the top flat and square. Then after the barrel is in cut the profile to that 1/16” , this will give you more to get a grip on and allow more wood for any unforeseen changes.

 

[The Appalachian]

An adequate 7 inch block plane is $30 at my local Ace. Flat is flat. Flat is when no light shines under a straight edge. Hit it with a flashlight and keep planing the high spots until it's flat. Flat isn't hard.

 

[Vaino]

I really don't concern myself w/ the flatness of the surfaces after the bbl is inlet.....most will be curves shortly. When drilling the pin holes for the bbl lugs and RR pipes, the bbl/stock ass'y is clamped in a vice w/ the top bbl flat against the permanent vise jaw. My drill press table has a 3-1/2' x5' x 3/4" thick sheet of re-enforced plywood permanently bolted to it and this easily accommodates the ass'y when it's horizontal for drilling. The lock bolts are drilled the same way. Actually the only surface that's really flat is the bbl's top flat. The tang screw is drilled w/ the buttstock clamped in the vise and a level on the top bbl flat ensures that the drill hits the trigger plate in

the center.

Once the bbl is pinned, both top sides of the forestock are filed down so they're 1/32"-1/16" below bbl centerline. This is done by "eyeballing" {even w/ a swamped bbl} and doesn't take very long because the sides are slightly more than 1/8" thick......Fred

 

[BadDaditood]

After band sawing the rough outline I pretty much hide all the power tools from myself.
I’m not under any production deadline. If I get frustrated or start to rush I put the tools down and sit with the dogs for a spell.

 

[Colonial Boy]

Unrestrained power tools can take only milli seconds to destroy hours of good work.

 

[deerstalkert]

only power tool after the bandsaw is a power drill. and i recently found my fathers old brace so am going to be using that for holes in wood.
i lied. i use a dremel to polish in tight spots.
oh yeah. if i get tired or find myself rushing something, i go find the list of honey-do's, choose the one dated closest to this year and do it.
takes no time at all to be back in the mood to work on MY project!

 

[Vaino]

I use a drill press for most of the holes....the main exception would be the 2 holes for the buttplate screws where a hole shooter is used. The Bpate is fitted w/ mostly a Dremel....first w/ a cutter and then a sandpaper wheel. First the Bp;ate return is fitted using a chisel and then a file but if the return is going be inletted, then it's a chisel.

Leaving too much wood on the Bplate curve can really slow things down......Fred

 

[rich pierce]

You need a Moravian jointer/planer for such jobs. That’s basically a fully trained gunmaker who chooses on the fly what hand tools he needs to get it to the chalk line. And the choices will depend on wood grain and other factors. Start with a frame saw and clean up with planes, spokeshave, rasp as needed.