Lehigh nose cap

[smallpatch]

I know this came up a couple of times, some time ago.  But, .... I need input on forming that open ended nose cap again.

Any help would be appreciated.

Last time, I just got frustrated, and poured it out of pewter.  I wanna do it right this time.

[Joe S]

This is very easy to do.  I’ll see if I can describe it to you.

I’ll assume you’re using a 5/16” RR.  First, cut the mortise to full depth, including the RR groove.  You can use a scrap piece of brass to be sure the mortise is the correct depth.

Next anneal the sheet you are using for the nose cap.  Take a 5/16” steel mandrel, lay the sheet on top of an open vise, and tap the mandrel down to form the RR groove.   It is critical to keep the groove square with the edge of the sheet.

Next, take a small C-clamp and clamp the brass sheet and mandrel into the RR groove.  It helps to have a flat filed on the mandrel for the C-clamp, plus you’ll want to put a small block of wood in the barrel channel so you don’t crush the wood there.

Now, just bend the sheet into the nose cap mortise.  You’ll probably need to anneal it two or three times as you go along.  When the nose cap is correctly bent, just place a copper rivet and you’re done.  It’s easiest if you leave the brass sheet a little long, and just trim the excess when you’re finished. 

If you haven’t riveted before, it helps to practice a few times on some scrap.

I’ve done this with 0.030” brass sheet.  0.040” might be a little too thick.

[smallpatch]

Joe,

Thanks so much.  I have a couple of questions.

The mandrel... a 5/16" rod or drill bit??

In forming the groove, how are you making the return, where it goes on the bottom ridges of the rr channel?

I assume you're using two rivets, one on each oblique flat??

[Joe S]

For a mandrel, I used a bolt – I just sawed the threads off and flattened one side a little bit.

Other than starting the RR grove in the vise, the entire nose cap is formed while the sheet is clamped to the forend.  That way, you get a perfect fit.  When you first clamp the sheet on, the ends of the sheet will be pointing down.  Just bend them up, and anneal as necessary.

I used just one rivet on each side.  On the brass side, make the countersink small.  You don’t need much material to get a tight joint, and you want the rivet to fill the countersink hole.  On the inside, make a countersink that is shallow, so that the rivet head is proud of the wood and contacts the barrel.  When you hammer the rivet, it will drive itself into the wood for a flush fit.  Don’t over do it, or you’ll crack the stock.  Also, don’t forget to anneal the rivet.

This is a method that I worked out for forming nose caps.  I’d be curious to know how other people do it.  You might contact Allen Martin and see what he has to say.  He makes a lot of these.  I’ve made one.

[Dale Halterman]

There is another way to do it, where the cap is formed of thinner brass and wraps under the barrel and down the sides into the ramrod groove. It is overlapped in the groove and rivetted there. It is inlet into the bottom of the barrel channel and in the ramrod groove, but not into the sides of the forend.

Eric the K described this method very well on the old board and it should be in the archives. I will see if I can find it.

Dale H

[Joe S]

I’ve seen that done.  Judging from the descriptions from other posts, it did not sound easy.   

Something I forgot to mention earlier – putting the initial RR groove in the sheet is not a precision operation.  All you need is a bit of a dent so that the sheet aligns correctly in the RR groove.  The RR groove in the sheet will be formed precisely when you tighten the C-clamp.

[Stophel]

Cheat.  Buy one of the Ted Cash ones with the ramrod groove, remove the soldered-on end cap and reshape it as necessary.     That's how I did mine recently.


 

[rich pierce]

Just make sure you have the barrel channel fully supported with a block made to fit if you don't have the barrel in place, else you'll split the thin wood for sure when you bend the "ears".

[Joe S]

Rich – I didn’t use a support block and I didn’t have any trouble with cracking from bending the ears up.  If you use 0.020” or 0.030” brass that is well annealed, there is actually very little force applied during the bending.  I did this twice, once on a dummy forend and once on the rifle.  I did have to anneal a couple of times during the bending.

Making the muzzle cap was the first thing I did when I was contemplating building a Lehigh.  I wasn’t sure I could do it, that’s why I made the dummy before I even started.  I had expected that making the muzzle cap would be the hardest part of the build, but it actually turned out to be the easiest.  It’s even easier than cheating like Stophel suggested, because the sheet conforms exactly to the stock profile, and you don’t have to do a bunch of real precise shaping to get an exact fit like you would if you used a preformed nose cap.

Take a close look at my muzzle cap and you’ll see that the edges of the RR groove are not identical, yet I still got complete contact.  I do have a crack in the stock, but that had nothing to do with the bending.  That was from a little overly exuberant hammering on the rivet.  I did that because I forgot to anneal that rivet first.  With soft rivets, there is no need to hammer very hard, and riveting is a reasonably safe proposition.

[rich pierce]

Good advice, Joe.  I never used stock that thin before.  I've been using .040 for nosecaps and thimbles.

[Acer Saccharum]

Rich, I have seen formed thimbles and nosecaps in the .025 range. That's using my micrometer eye.

T

[Dale Halterman]

http://americanlongrifles.org/old_board/index.php?topic=4496.0

Try this thread for Eric's description of the full wrap around type. I did one this way and it was actually pretty easy, except that I did do a sloppy job on the rivets. And I used .015" sheet brass instead of .025, which made it really easy to bend.

Dale H