Winchester only chambered Low Walls in 32-20 and 44-40.  Anything higher power got put into a high wall.  That means that Winchester thought it was unsafe to put a 32-40 on a low wall, let alone a 38-55, BP or not.  If Winchester thought it was unsafe 130 years ago you shouldn't do it today.

The low wall was made because it is a fumbly process to load a high wall with a small cartridge.  If you cut down the walls you can load a small cartridge much more easily.  You give up lots of strength but you don't need strength to shoot those small cartridges anyway.   

I have seen a few 32-40 Low Walls and even a 38-55 Low Wall (non-original of course).  They may work for a while but I am not standing next to a guy shooting one.   

40_Rod wrote on Sep 11^th, 2016 at 9:53am:


One of the horrible things about the .38-55 is that it will chamber and fire the .375 Winchester, which is a high pressure round loaded for their beefed-up Big Bore levergun.  SAAMI max pressure 55,000 psi.  Commercial loads said to be about 50,000 psi.   Just one of those will probably scatter a Low Wall from here to breakfast.  

An industrial safety variant of Murphy's Law that I've had to live by through years of designing automation is:  "If it can happen, it will happen."  No matter how the barrel is marked.  

I stated earlier that I kinda liked the idea of .357 Maximum, using only black powder.  But I'm remembering that there was hot loaded commercial Max ammo in the past, and with the resurgence of the round for use in rifles, I'm seeing quoted velocities that put the pressure up in the 50,000 range from the custom loaders.  So I retract my suggestion, and would go for .357 Magnum instead.   

Nathan,
Going to give a Cartridge Thrust 101 lecture.
Cartridge thrust is the force of the cartridge base on the breechblock.
It is determined by the cartridge pressure multiplied times the area of the cartridge base.
Cartridge thrust for the same pressure increases by the square of the diameter of the cartridge base.

The original Low-Wall is a weaker design because the receiver reaction shoulders are significantly below the center of cartridge thrust.
This causes the breech block to work like a pry bar and increases the stress on the receiver shoulders. Have you crushed wood or metal with a pry bar?
Lack of support on the lower ejector side adds to this.
The Low-Wall is a fine action for smaller base diameter, low to medium pressure cartridges, but just not designed for higher performance cartridges.
The same design with the receiver reaction shoulders above the center of cartridge thrust (High-Wall) will handle most any reasonable cartridge
Chuck

I personally prefer to keep my red blood on the inside of my skin, and have my mind directed to keeping it that way.
    

I decided to compare the pressure on the block of a 38 special (22000 psi) to the block pressure of a 38-55 using black powder (17000 psi). I'm unsure of the actual butt area of a 38 special cartridge or a 38-55 cartridge, but my calculations are based on the 38 special being .357 while the 38-55 is .380.  Although the butt of the 38-55 cartridge certainly has more area than 38 special, I was surprised to see that the 38 special pressure on the block is about 10% higher than the 38-55 black powder cartridge (Pi X (.5 X radius squared) X psi).

So, if my numbers are right, it SEEMS that a 38-55 black powder cartridge will not overpower the receiver or block any more than a 38 special.  

However, I agree that we do have some responsibility to protect those who might misuse a black-powder labeled 38-55. I'm unsure how much responsibility to assume. I know that I'd probably feel horrible if my grandson put a modern round in my low wall and hurt himself. At the least I assume responsibility to properly label it, and maybe even to warn him severely if I leave it to him in my will. It's hard for me to assume responsibility for those who fail to read the "black powder only" warning. When I leave him my 62 cal black powder flintlock, I run the same risk that he could try to load a mixture of BP and modern gun powder in it. Old guns commonly used BP, and so do some modern guns labeled with a warning against using anything else.

Do I need to warn those who buy a 150 mph motorcycle that those speeds can kill them? Do I need to warn a parent to lock up their handguns? Are gun manufacturers responsible for those who misuse assault style rifles? I think our political parties are presently fighting over issues like these. 

At this point, however, I'm still looking at all the possibilities before spending $. So far, the three options seem to be 1) use a low pressure round, similar to a 38 special or smaller, 2) re-barrel for a 22 hornet, 3) re-barrel for a black powder only round, 38-55 or smaller. Of those three possibilities, I'm still more intrigued with the possibility of turning this rifle into a 22 hornet varmint rifle. But from what some are saying, I may need to ask the smith to replace the large firing pin with the small one. Even if I have him replace the large for a small firing pin, is the 22 hornet still a reasonable option?

I know it seems like I'm taking you guys all around on these issues, but I really really do appreciate your input.

Sell it for the action and get a modern bolt action. It will cost you far less. A low wall IS NOT suitable for a 38-55 or anything larger than a older pistol round. It is not suitable for a 22 Hornet either. Not suitable for any rifle round. Modern 38 Special would be pushing it limits and I would not trust it. In my opinion.  Take it for what it is worth.

I just made a table of comparisons for different calibers to compare the thrust on the 1885 block (see attachment 1 for pdf format). The ones marked *** indicate the common calibers marketed for the 1885 LW.

I was surprised to see that the 32-20, 38-40, and 44-40 all show slightly higher thrust values than the 38 special. The thrust for 38+P seems almost perfectly matched to the 24,000 psi design limit that some people recommend. 

For me, the most obvious problem shown by this table is that the 22 Hornet seems somewhat overpowered (11% higher) in comparison to the design limit. 

I suspect that a host of other factors might be just as important as the thrust load. But this table has helped me to consider ruling out the 22 Hornet for a LW.

In the table, BP indicates black powder cartridge. So the 45-70 is obviously way too powerful even in a black powder cartridge.

Nathan,
Because you are a research scientist, Google ANSI/SAAMI Z299.3 and ANSI/SAAMI Z299.4 for manufacturer's standards for pistol and rifle cartridges.
Anything else is a guess and even they disagree on copper units of pressure vs. transducer data.
For action strength, pressure alone has very little meaning unless the cartridge diameter is specified.
The thin wall brass tube cartridge has very little effect on cartridge thrust.

For barrel shank information, Google "thick wall cylinders" and find formulas to calculate stress.
Use the thread root radius or the smallest radius on the shank and the largest radius of the cartridge chamber.
Chuck