Hey guys, I have an 1886 40/65 and a 1895 38/72 that are all correct but the bores are shot. No pun intended. Both just well used gray rats. I would like to make shooters out of them again but don't want to ruin history. Toss a coin?

If they are gray rats, they have little collector value. Neither of those cartridges are very exciting. Were they mine, they would be rebored to 45-70 and or 50-110, a lot cheaper than a custom reline job.

I personally would consider a reline, but you could always re barrel as well, and keep the originals with the rifle. Just more money that way. I've had rebores done too, JES cN help you out there. I've had him do two model 70's and he's fixing to turn another one into a 358 Norma for me.

The availability of .45-70 ammo and reloading components would make it my choice as a rebore. Reline is more costly and ammo/reloading components for the calibers you mention would be hard to come by.

Thanks for the advice. I already have the dies and components to reload both calibers. I would like to keep same calibers. I enjoy shooting the odd stuff and black powder cartridge. Wouldl I have to open the bolt face for a rebore to 50-110?

FWIW I have an 1886 in 40/82 with a grey bore and pitting. Not ugly, but far from good. I spoke to the folks at Buffalo Arms up in Idaho and on their advice I slugged the bore (used a soft lead sinker) and mic'd it to the best of my ability. Then I was able to select the right bullet and it has a copper gas check on the base. I shoot only black powder and it is very accurate. Per the guys at BA the gas check certainly helps and it seems so to me. I use it to compete in the occasional long range match in Cowboy Action Shooting, out to 120 yards, and do just fine. Clean up is not an issue either.

You have to ask yourself just how many 40/65 and 38/72's there are around in original used condition.
Then decide if you want to make 2 less of them.

Personally I would leave them as is or sell them and buy shooting condition models. But they're yours and you can do as you please. The '86 could be easily opened to .45-70, but the '95 is a different story. The largest caliber the '95 was offered in was .40 (.40-72 or .405) and the .38 bore may or may not be suitable for rebore because there's only .030" difference. Also the magazine and feeding system is not suitable for larger diameter cases. The .38-72 was black powder and the barrel steel may not be suitable for the higher pressure smokeless .405, so you'd be best going to the .40-72.
In the long run I think you'd be better off doing as Razz did and play around with some cast bullets and find one that shoots acceptably and enjoy them as they are.