Last week, I inherited my grandfather's 1889 vintage 1885 low wall that appears to use a 45-70. I say "appears" because my uncle confessed that about 10 years ago he sanded the rifling with a rotary sanding drum on a dentist drill--so no rifling remains. However, a 45-70 cartridge seems to fit the chamber perfectly. The rifle was born as a 32 WCF but the original barrel had been replaced.

I love to hunt and want to restore the rifle to hunt deer with it. And when I die, I'd like to will it to my grandson so he will have the rifle that his great-great grandfather used. He also loves rifles as much as me. This means that I need to re-barrel the rifle. Here in Missouri I can expect a 100 yard shot on average, and sometimes up to 150 yards. Who knows where my grandson will settle as an adult, so I'd like to restore the gun to something that shoots fairly well out to about 150 yards. 

Since the chamber pressure for a 45-70 is somewhere around 32,000 CIP, I assumed that a 45-70 is too hot for a low wall  receiver. Most of the recommendations I've read about a low wall indicate that I should re-barrel to a caliber that keeps the pressures below 28,000, and some even say below 24,000. However, a local gunsmith notes that the 45-70 cartridge is straight-shanked and therefore exerts a lot of the pressure on the chamber walls instead of pushing back against the falling block. He warned me about using any high pressure cartridge that tapers, saying that the block may not last over the years if a high pressure cartridge pushes primarily against the block. He said that I could use black powder if I'm still concerned about the pressure.

A second option is to re-barrel for a 45-60 (28,000 CIP), or maybe even a 40-82 (24,000 CIP) This would mean hand-loading all rounds. I don't mind that, but it could be a nuisance for my grandson when the time comes for him to inherit it. I think the 40-82 may use a tapered cartridge, so maybe the 45-60 would be easier on the receiver than the 45-70 or the 40-82 over the long haul?

A third option is to mark the barrel for black powder only. I'm an avid flintlock shooter so my grandson will inherit my other black powder guns anyway. He loves my flintlock, so I expect that he'll be OK with using a black powder rifle. 

This will certainly end up as the most expensive "gift" that I've ever received--expensive FOR me, that is. So I appreciate your insights and guidance.

Your grandfather/uncle must have been thinking of using it for .45-70 shot cartridges.  I've seen another instance of a .45-70 smoothbore barrel on a weak action.  The Government had shot cartridges made for troops to forage for food with in  the days of the Trapdoor.   

I'm in total agreement with Frank.   Smaller cartridges, even at BP pressure.   Like the BP .357 Max idea.   

There's a caution about Max reamers - SAAMI reamers don't cut a very good chamber in a rifle.  Read Mike Bellm's various screeds on the subject.  I had a proper reamer made for me by Dave Manson.  Bellm does chambering for T/C Contenders with a similar one.   

Max brass has been scarce, but just today I got an email from Bellm in which he mentions that he has a new source opening up.

Well, I suspected all along that hoping for a 150 yard deer gun from a LW was probably expecting too much. However, I have also wondered about getting it re-barreled for a 38-55 marked for black powder only?

Regardless, I am also intrigued with the idea of re-barreling it for a 357 mag. I guess that I could re-barrel it or get the existing barrel relined. The existing octagon barrel is fairly beat up, but so is the rest of the rifle. As a 357, should I get a new barrel or get the existing one relined? No matter what, the collector value is 0.

None of the modern high pressure varmint rounds would be suitable for a LW action. They're just too much for that great old action.

What people are trying to say is: An original Low-Wall just won't take high pressure cartridges or even larger cartridges at lower pressures.
It will crack the receiver at the right rear corner of the breech block opening.
Just not a long range action. About the best varmint cartridge for it would be a .25-20.
Chuck

May I suggest the good ol' .38 Spl. ? It'd be fun for the youngster, and cheap to shoot as well. Not likely a magnum round will ever enter it to threaten his well being. I had one in .32-20 and it was pleasant to shoot as well, but not as cheap to feed as the .38 would be.
When the time comes, get him a deer rifle- till then just have a good time with a neat ol' shooter he can affford to shoot a lot.

Oh, get a 14 twist liner if possible, so the 38 can if desired be loaded with up to 200 gr rifle bullets. I like the 200 gr Lyman cast bullet #358315. Shoots very well in my 13 twist.
beltfed/arnie

One of the above posts mentions an option for barreling in a 22 Hornet. That interests me. However, in another post about Low Walls, I found that John Taylor mentions, "Most have too big a firing pin to be safe with the hornet which is rated at 43,000. The hornet is good for blowing holes in the primer even in a strong action." Depending where that primer and firing pin go, I wonder if it might ruin my day. 

If I used only factory loaded 22 Hornets, would that still be a problem, or is this primarily a problem with hand loaded 22 Hornets? I think I know the answer, but as a newbie I have to ask even the dumb questions.

And if I opt to re-barrel to a 38 special, would a 38+P be OK? These may seem like dumb questions, but I need to know what I'm doing.