Trap door repair

[HWooldridge]

My daughter-in-law’s grandfather likes to buy pawn shop specials and picked up a trapdoor carbine in 45-70 a couple months ago. He knows I enjoy old single shots and showed it to me last weekend. They have a big ranch so I took a couple dozen BP handloads with me, consisting of 45 grs. FFg and a 400 gr. boolit. We shot all of those rounds and had a great old time - the old girl is quite accurate, especially for its age.

The gun is generally in good shape but the chamber is sufficiently pitted over its entire length that the cases want to hang up. There are also a couple of light rings that hinder extraction. Grandpa has plenty of money and wants to get it fixed but he doesn’t do the Internet so asked me to do research.

My question is whether it’s customary for this type of repair to pull the barrel, face off the end, set the shoulder back and rechamber - or is it better to bore it out and sleeve it then recut the chamber? I can see advantages to both; the latter might be less work but I’d probably leave it to the gunsmith.

Anyone have recommendations for a shop that might specialize in this type of repair?

TIA, HW

[john.k]

If originality is important,just sleeve the chamber ......no need for a reamer,just bore the new chamber with a small boring bar........most gunsmiths have done this to many antiques with damaged chambers,and a few modern guns with damaged chambers.............I have thought,but never tried it,that electroless nickle plating could fill chamber pits and gouges......However ,the electroless kit is quite expensive,the chemical doesnt last,so sleeving is a cheaper alternative.

[Geezer in NH]

I would buy a used barrel from somewhere.

[elmacgyver0]

Have you tried to just polish the chamber?

[HWooldridge]

Have you tried to just polish the chamber?

Not yet, still gathering info before I talk to him.

[Nobade]

Yes, pulling the barrel and polishing it is what I would try first. BP loads can function with surprisingly rough chambers if you get all the rust and sharp stuff out with sandpaper.

[Alasgun]

Replacing the barrel makes the most sense from both a time and expense standpoint. There’s numerous places you can buy a good barrel up to and including e-bay!

[Deadeye Bly]

If the chamber is ringed no amount of polishing will help. Either option will work but sleeving the chamber is less work because reworking the extractor cut would be easier. Quite a few gunsmiths can handle this. Finding a suitable replacement carbine barrel may be difficult. John Taylor in Idaho can handle this. htttps://johntaylormachine.com Let him determine the best way to proceed.

[KCSO]

I have on occasion had luch sleeving just the chamber by turning and threeading it and screwing in a threaded insert.

[HWooldridge]

Many thanks for the responses - turns out the polishing method seems to have fixed the problem on two guns. Both this trap door and a rifle I recently obtained from someone on this forum had chambers where a light rust layer had formed inside, which I believe was acting like sandpaper and gripping the case when fired.

I made a wooden mandrel from some hardwood dowel and polished both with emery grit cloth (crocus cloth) and cutting oil. Started with 240 and went to 320; ran them wet like I was honing a brake cylinder. Fired cases dropped out afterwards with complete ease - absolutely no sticking.

I suspect some of the older BP guns might have more rust in the chamber than the barrel because light rust is probably pushed out by the projectiles, but the chamber relies on the owner removing all of the residue and not allowing any to form. A little here and a little there and over the years, a light crust can form, which may or may not cause any problems.

Regardless of the cause, we are both happy with the results and are back to shooting our period pieces.

[Nobade]

Glad to hear it worked! Way better than having to cut metal.