Anyone shooting the 50/70 or the 50/90 cartridge

I used a 50-70 rolling block barrel to make a sleeve for one of my rifles. I used the original chamber which was a mistake because I think the chamber was a bit on the long side. That barrel likes a Loverin style bullet (several narrow grooves) I think because it carries the full diameter of the bullet farther forward and closer to the start of the rifling. It does not like the government style bullet which has wider grooves and a sharper point and cannot be loaded out far enough to closely approach the rifling

cheers mooncoon
 
I bought an old Sharps Borchardt supposed to be a 45/70. A 45/70 falls into the chamber rim and all. I don't have the measuring tools to measure it. and would prefer not to take it apart and wreck a screw or two.Anything I have read so far says they were built in 40 and 45 cals. Barrel is pitted on the outside but the bore is cleaning up pretty good the more I work at it ( badly leaded )
 
You need to do a chamber cast. I shoot both 50/70&50/90 but there is no way to tell what it has been rechambered to. Good luck Ps: get a good micrometer it will pay for itself many times over.
 
a j cave said:
You need to do a chamber cast. I shoot both 50/70&50/90 but there is no way to tell what it has been rechambered to. Good luck Ps: get a good micrometer it will pay for itself many times over.
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In addition to echoing AJ, use some patching or paper towel to block the barrel a short ways into the bore. Tie a piece of string to the plug before you put it in place. Fill the chamber with paraffin wax and when hard, knock it out. The purpose of the string is that if/when the wax casting breaks, the pieces stay together so that you can measure them. In a perfect world, you would use Cerrosafe but I am guessing that you don't have any and wax makes a good and inexpensive alternative

cheers mooncoon
 
mooncoon said:
In addition to echoing AJ, use some patching or paper towel to block the barrel a short ways into the bore. Tie a piece of string to the plug before you put it in place. Fill the chamber with paraffin wax and when hard, knock it out. The purpose of the string is that if/when the wax casting breaks, the pieces stay together so that you can measure them. In a perfect world, you would use Cerrosafe but I am guessing that you don't have any and wax makes a good and inexpensive alternative

cheers mooncoon
Click to expand...


Your right no cerrosafe. I thank you for the wax idea I shall try that
 
Melted Sulfur will work also, the good: melts at a low temp and is a bit stronger than wax. The bad: absolutely do it outside, stinks like hell and your significant other might change your arrangements if you do it inside, don't sit downwind of your pot/burner as the fumes can be a bit noxious
 
Well i poured a few Paraffin wax moulds of the chamber, all were just about exactly the same except i could not to the rim. I could get a decent inner edge though. Here are some measurements 2.260 from start of the rim where it meets the cartridge to end of cartridge. .670 at cartridge base just ahead of the rim and .560 at cartridge end where you would start the bullet. Start of bore 1/2 inch in is .465.
Next thing to do is find something of a size to slug the bore.
So with that any ideas as to what i have here?
 
Also if looking in the chamber it seems to have a bit of a step on one edge. It is not even all the way around from chamber into bore. I have a picture of the mould i made that shows it. Being on a land line i could not post it kept getting timed out if someone would message me i could text a picture and they could post it.
 
the cartridge is not a 50-70 for certain. It sounds like a 577-450 off the top of my head. The slug on a 50-70 is .515 and if my memory is correct the base diameter of the shell is around 530 or 540.

cheers mooncoon
 
the photo of the wax casting is below. It does not look like a cartridge chamber and if I were to guess, my guess would be that someone has drilled the chamber out with the intention of installing a chambered bushing. Perhaps the original chamber was damaged or a previous owner wanted to form shells from a cartridge that was readily available

cheers mooncoon

qaO7ZMd.jpg
 
There are no grinding or drill marks in the chamber. The extractor fits properly all the way to where the rim of the cartridge would be. Also the witness mark on the underside of the barrel still has the sharp corners so it looks like the original barrel has never been removed. The only number on the bottom of the barrel is a 84 with three marks that look similar to dollar signs.
 
the difference in diameter of the "neck" of the shell (if it is a chamber) and the diameter of the bore should be around .020". That assumes a wall thickness of the cartridge to be .010". If the chamber is drilled out, the base and neck diameter should be very close to the same. To my eyes the difference between bullet diameter and cartridge neck diameter looks a lot greater that .010" wall thickness. Hard to tell fom a distance

cheers mooncoon
 
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