Questions regarding original nipples in an original British 16 bore muzzleloading shotgun.

[Ironoxide]

I finally took my original British shotgun to the range and I patterned few loads in it. In preparation to it I measured the bores and I discovered my 20-bore is actually a 16 bore

After shooting came time for cleaning. During firing I noticed no excessive gas leakage, but the area surrounding the nipples was definitely heavily fouled with powder residue (after around 20 shots each bore). My modern made replicas don't seen to have powder fouling there, instead there is cap residue. This was the first clue something is different.

When I removed the nipples for cleaning I inspected them throughly and I noticed they have a very different construction than modern nipples. It appears internally the nipple has a tapered cavity that is narrowest at the very top and as open as it can be at the bottom. I attach a picture below. Modern nipples have a larger diameter cylindrical cavity from the top reaching to almost the bottom where a small hole is drilled. The size of the hole in both modern nipples and those (I assume) originals is similar. However the fouling is not.

So my question is, is this a typical style of nipple used at a time, or was it remade by someone who never saw a modern nipple and that person just came up with this design? If you have an original British shotgun from the period can you check please?

Also, as there is more fouling do you think I should make modern style nipples for the gun, or perhaps the fouling gets out through the threads and some Teflon tape will resolve the problem.

Here are some pictures.

The orange color is not rust. It is copper anti-seize I use on all my nipples (that sounds bad, let's clarify "all my gun's nipples")

 

[Sam squanch]

That’s just how they were made back then. Most originals I’ve seen were like that

 

[desi23]

Don't have any experience with British shotguns but my two original British muskets have nipple made that same way. As to the powder fouling it may be coming back up through the nipple and then being blown down by the hammer cup. Are the caps thoroughly shattered or even missing after firing? That could be a sign that there's a fair bit of powder gas coming up through the nipples when firing

 

[Ironoxide]

Thanks for answers. If that's how it was made I'll probably leave it as is. I'm not planning on shooting the gun that often. I have modern replicas for frequent use.

The caps looked pretty normally to me. Yes they were somewhat blown, but no more than usual I think.

 

[DuncNZ]

If your the hole in your nipples gets too big it can blow back the hammers and may break things like the tumblers , hammers and main springs . It is better to fit new ones if you can .

 

[ohio ramrod]

Did your caps fire readily? I noticed that the end of the nipples are flattened. Sharpening the tips will improve performance.If you can't find replacements a good machinist could "reline" your origonals with a steal "t" shaped liner. I have had to do this with old odd thread nipples and they performed well.