Wood thickness between ramrod and barrel?

[Scota4570]

I am planning an Armstrong style rifle.  My first attempt at an Armstrong used a precarve and a 13/16" barrel.  The thickness of the web is 0.26".  It looks to chunkie to me.  I measured my Kiblers and got about 0.15" on the SMRs and the Colonial.  The Woodsrunner is about 0.21". 

What is a good rule of thumb for the thickness of that web of wood?

I was thinking of using another pre-carve and inletting the barrel deeper.  Are there problems that I am not seeing? I would not get any precarve with the lock inletted for me.    How about the trigger plate being positioned wrong after?  Or, the lock sitting too low with a properly swamped barrel?  In letting the ramrod channel deeper would not work due to the hole under the forearm not lining up?.

Or, just work from a plank? 

[Steeltrap]

I think you would be ok going with a pre-carve. I would not go with a pre-inletted. You can't change much of anything with a pre-inlet.

Web thickness on pre-carve's (in my amateur experience) are usually thicker than what you need....or what should be. It's not all that difficult to make the BC deeper as you haven't cut in for the lock yet.

But frankly, if you have built firearms before, I'd say buy a plank and have the barrel channel cut and the RR hole\channel cut. You can take the barrel channel down deeper if you like and you have a "blank canvas" to work with.

As you know, since everything else is measured in some form or fashion from the barrel, just take it from there.

FWIW

[Sidelock]

For reasons already stated, I would just start from a plank.  As for web thickness; I do my own barrel and ram rod work the old school way.  I shoot for a web at the breech of 1/8" and with most swamped barrels, the web at the muzzle runs 5/32 +/-.  Biggest pain with the r/r channel and hole is getting that sucker running exactly parallel and centered with the bore.  There are always those r/r holes that don't land where you want them, then it's time to do what you are thinking of, drop the barrel a touch, if the hole dove on you, if you shot the hole high, then the repair is a little more complicated, but that is another subject. 

[mgbruch]

I like a 3/16" web at the muzzle, and 1/8" at the breach, because I like to get the gun as slender as I can.  1/16" over plan doesn't make much difference in the look and feel of a gun... but 1/8" does.  A fine gun requires fine tolerances in both planning and execution.

[Bill Raby]

I go with about 1/8 inch. Easier to build from a blank than a pre carved stock.

[rich pierce]

Of course it’s good to remember that the tabs on your underlugs can’t be taller than the thickness of the web. And you’ve got to drill and insert a 1/16” pin in the tab, leaving extra metal above the hole in the tab (or is it below?). For the front lock bolt you’ve got to fit a #8 bolt in the space between barrel and ramrod hole. If you have capability to drill within 0.020” accuracy, a super thin web sure looks nice, even if you have to notch the barrel first the front lock bolt. If you’re not a pro or a machinist, an extra 1/16” of web can save some headaches.

[Steeltrap]

Of course it’s good to remember that the tabs on your underlugs can’t be taller than the thickness of the web. And you’ve got to drill and insert a 1/16” pin in the tab, leaving extra metal above the hole in the tab (or is it below?). For the front lock bolt you’ve got to fit a #8 bolt in the space between barrel and ramrod hole. If you have capability to drill within 0.020” accuracy, a super thin web sure looks nice, even if you have to notch the barrel first the front lock bolt. If you’re not a pro or a machinist, an extra 1/16” of web can save some headaches.

Rich, if the space is "really tight" I've used #6-32 lock bolts. They seem to work fine. Do you see any issues using this smaller diameter bolt?

[rich pierce]

Of course it’s good to remember that the tabs on your underlugs can’t be taller than the thickness of the web. And you’ve got to drill and insert a 1/16” pin in the tab, leaving extra metal above the hole in the tab (or is it below?). For the front lock bolt you’ve got to fit a #8 bolt in the space between barrel and ramrod hole. If you have capability to drill within 0.020” accuracy, a super thin web sure looks nice, even if you have to notch the barrel first the front lock bolt. If you’re not a pro or a machinist, an extra 1/16” of web can save some headaches.

Rich, if the space is "really tight" I've used #6-32 lock bolts. They seem to work fine. Do you see any issues using this smaller diameter bolt?

No, I think it’s fine. There’s really no stress there. I often have to file a groove in the bottom of the barrel. I’m of the opinion that pushing the limits on minimal web thickness can lead to problems for those new to building from blanks. Plus, plenty of originals had fatter webs. Certain “best practice” rules were not followed by all, back on the day. When I’ve disassembled original flintlock guns I see plenty of underlugs 3/16” tall.

[Clowdis]

I use 3/16 between the breech end of the barrel channel and top of the ramrod channel. This gives me a little more wood between the ramrod and the barrel at the muzzle. The reason I use 3/16 at the breech is to allow me to get the front lock bolt between the barrel and ramrod channel. If I use a #8 (.160) bolt I can barely get it through without breaking into the barrel or ramrod channel.

[Scota4570]

Thanks everyone,

So, the ramrod channel must be straight to allow drilling into the forearm?  Does it remain straight or is the channel bent inward after drilling to make the web thickness the same down the length for the fore arm.

[rich pierce]

Thanks everyone,

So, the ramrod channel must be straight to allow drilling into the forearm?  Does it remain straight or is the channel bent inward after drilling to make the web thickness the same down the length for the fore arm.

99% use a straight line groove and hole. Some skilled makers can set up the groove to follow the swamp somewhat and drill it that way by bending the forestock, or so I’ve heard. Others occasionally modify the forestock and groove “some” after drilling using the straight setup. Unless the amount of swamp is exceptional and you’re going fur a special look I’d go straight. It confuses me when I think of hue s forestock molding would look if the web followed the curve.   I just drilled today and thankfully it came out right. It can get confusing laying it out on a crooked blank where  nothing is exactly true.

[Scota4570]

Crooked precarves drive me nuts. 

On a plank build I make it square and straight before I start.  I work more like a machinist than an artistic carver.  I can make nice drawings by drafting but I can not freehand draw very well.  I approach stock making with that mindset.  Making a square gun then shaping it after takes the guess work out for me.     

It was suggested that I have the barrel inletted and the ramrod channel cut by a specialist.  I have never farmed that out but will check in to it. 

Scot