inletting butt plate on chambers fowler

[serenget]

hi guys,
i've just had some trouble inletting a fowler butt plate - it's my first build.
there is obviously some rigidity in the heavy brass cast supplied by jim with my kit and as a result i found it difficult to cut the inlet for the rather complicated shape of the extension (the tab got in the way too but i cut a decent slot for that so it wasn't an insurmountable problem).  i found it difficult to inlet the extension even after i cut out the excess wood at the back of the stock because i couldn't position the extension in the correct place on the top of the stock, at least enough to accurately scribe around its shape. the casting needed some force applied to it to conform the extension forward into its correct placement.  probably had i screwed the butt plate more or less in position at this point i would have been alright,  because this would have flexed the casting enough to hold the extension in place for scribing.  but in the event i inlet the extension back into the stock in the horizontal plane, cutting little by little as i went.  the job i've done is ok but not great.  with this method it was almost impossible to get a good fit,  even when using inletting black.  also,  even with this method i had to gently tap the butt plate casting backwards, to achieve a fit, and this inevitably led to some chipping on the stock as the extension was moved back into place.  i've managed to deal with the chipping problem by careful sanding of the stock and butt plate in situ, but i still have a few unsightly gaps around the extension part of the butt plate as a result of my inletting method.
so the question is what could i do to do a better job next time around?

[Eric Krewson]

I feel your pain, I have more time in this buttplate than some guys spend on a complete rifle. I thought I would leave some extra wood to"practice" inletting as I put this buttplate in place, big mistake. I caused myself at least 40 extra hours of work by this decision.

[rich pierce]

Depending on how much this bothers you there are fixes.  You could stretch the buttplate easily up to an additional 1/16" wide and 1/8" long by careful peening of the underside.  First make sure the buttplate is brass and not a bronze alloy.  Anneal the buttplate if it is not soft enough.  Now take it off and place the extension upside down on the anvil.  If you are good with a hammer and have drawn metal before (blacksmithing) have at it with the ballpeen hammer or a rounded crosspeen hammer to widen the extension.  Use the ballpeen to stretch it lengthwise.

The quality you get will depend on the anvil being smooth and the hammer being smoothly rounded too, as well as your skill.  Many, many well directed blows with the hammer will do a good job without making things all bumpy on the exterior.  Think of tapping along like you would with an engraver.  Or like a sewing machine stitching a seam.

If you're not so confident, have somebody hold the buttplate in place for you.  Now place a nice well finished ballpeen hammer knob wherever needed and use the hammer like a punch, striking it with another hammer.    Tap tap tap 1/8" behind the edge pushing outwards, all along from heel to tip.  Repeat closer to the edge.  Then another line of strikes closer.  Alternate sides because the metal will curl to one side in an arc as you stretch it.  When you are all done stretching the buttplate will need to be straightened.  All this only works with annealed soft brass.  Get it oversized then re-file the draft on the edges and re-inlet.  Also taper the buttplate thickness down to 1/16" at the edges and it will look better and conform more easily to the stock by tapping with a copper mallet.

[Acer Saccharum]

Great tips on stretching brass, Rich. Tx.

[serenget]

thanks too for the tips rich,
i can see that this would work well in my case (to solve the gap problems which aren't too bad)
but there are pitfalls in annealing as i've just found out.
i tried annealing the plate today - but i guess i got it too hot because the casting completely fractured in a number of places when i picked it up to quench in water.  the metal grains were remarkably large on the broken surfaces.  to be honest i was surprised at the breakage because i thought that i didn't heat up the casting enough - certainly not beyond red,  but i'm going to have to chalk this up to experience and get a new plate.
but it makes me worried about trying annealing again.
perhaps i can just peen the casting without heating and annealing?
or how can i prevent overheating when trying this method?
on the general inletting front,  i still find it difficult to visualise the process of inletting for the extension whilst moving the plate backwards on the stock, particularly if i can't scribe around the extension because i can't get it close to the top of the stock (enough to make contact with the wood and give an accurate outline).
any further thoughts on this process?
best,
matt

[rich pierce]

Sounds like a bronze alloy. Many wax cast "brass" furniture pieces are made from a bronze alloy that casts well but is not workable.  If it is a bronze alloy then annealing it or peening it  to stretch it is not possible.

I should have said that with yellow brass, very dull red in a dark room is as high a heat as one ever needs to anneal brass and the quench is optional.    Sorry this did not work out. 
Is this your first buttplate inlet?  Do you have a longrifle building book or two?

[Mark Elliott]

The peening also works with wrought iron and mild steel.   I use it to tighten up loose cocks and stretch lock plates.    I also use it to fit up both brass and iron butt pieces.   However,  when fitting mild steel butt pieces,  it is best to file the edges down almost to finished thickness before trying to hammer the edge to fit the wood.    I have also stretched out the edge of tangs and trigger guard extensions to close up gaps.    Remember,  if it don't fit, get a bigger hammer

[Mark Elliott]

I guess that I should also make clear that the material must be annealed or pretty close to it for this to work safely, and if there was any doubt,  I was kidding about the bigger hammer, kinda.

[rallen]

Check the fractures for ceramic from the mold in the metal that may have weakened the brass.
Depending on the severity of the gap, it still may be possible to salvage the inlet by moving the butt plate forward since everything tapers to that little tang.  As you move forward, you end up closing all the gaps. File the wood off the butt to do this and re-inlet the forward tang of the plate.
For me, the key to installing those butt plates is to go stright down. Also orient the forward tang on a centerline of the comb by fitting the plate to the butt. 
Ryan

[serenget]

Thanks for the posts.
Straight down would seem to be the way to go.
But a couple of things:
I spoke with Barbie @ Jim Chambers' today who was very helpful. She confirmed that they supply yellow brass fittings.  And that these are soft enough to hammer without any heating.  Apparently they hardly ever have to anneal their fittings in their own workshop.  Although stretching butt plates through peening with a hammer and anvil is quite common practice in order to correct small inletting problems.
So one to chalk up to experience.
A new butt plate is on it's way to me....
I'll see how I get on this time...

[Micah2]

I recently finished a Chambers PA fowler. It was my first build as well.  It went very well and I love the gun, but I had my share of difficulties as well.  For starters, I realized that these kits are already very close on the wood to metal fit.  So close that it appealed to me as a first time builder, I thought it would make it easier.  What I learned is that they are so close that care must be taken in preparing the pieces for inlet by filing and relieving the backsides of the brass with a file before I even think about tracing the inlet to the stock.  It helps to file the buttplate lug, particularly the rear side of it closest to the butt and imagine that as the buttplate goes in, it needs to actually slide forward for tight lines on the inlet.  Of course I also learned that it is very important to inlet on an angle and never close to straight, thereby allowing wood  to contact brass and metal constantly until a final fit is achieved. 
Best thing I ever did was to purchase and study Peter Alexander, Gunsmiths of Grenville County.  Even for a kit build.

[keweenaw]

You can also help yourself about that needing to flex the BP forward to have the extension hit at the front by drilling the screw hole in the stock slightly forward of dead center of the BP hole.  The taper on the screw head will then pull it forward and tight.  It's hard to do this off center drilling precisely with a twist drill bit in a hand drill but a gimlet makes it really easy.
http://en.wikipedia.org/wiki/Gimlet_%28tool%29

Tom