Dutchman
07-08-2008, 04:34 AM
These questions are from a newbie in this forum, Paul T., who calls himself a Dutchman simply because he lives in the land of the Dutch. And because of that he's like a 1st cousin...:) We are also the same age of 56. He sent the questions in email but I thought there may be interest in the subject in this forum.
reference:
http://www.rebooty.com/~dutchman/12744r.html
http://www.rebooty.com/~dutchman/6774.html
http://www.rebooty.com/~dutchman/1885carbine.html
http://www.rebooty.com/~dutchman/1867sporter.html
Pay close attention to this page:
http://www.rebooty.com/~dutchman/RBfailure.html
I ordered a Lee bullet sizer/lube kit in .510
Generally, .512" is what I've found when the grooves are measured with the inside knife edge of dial calipers. Not all rifles are going to be the same but we've found some a little more into .514". The U.S. cartridge of the 1868 period was the .50-70 Government. The bullet was .515" with 70 grains of Ffg powder and a 450 grain bullet. The 12,7x44R is a smaller version, narrower in the cartridge head, a little shorter in length and the original bullet was 345 grains with 75 grains of black powder. In the U.S. we would refer to such a cartridge as this:
.50-70-450
.50-75-345
If you have access to a lathe you can polish out the interior of the Lee sizer die with 320 grit - 400 grit - 600 grit then crocus cloth lubricated with a watery petro like WD40 if you have that in Holland. Kerosine or diesel would also work but with fine grits of emery cloth you need a thin lubricant, not a viscous oil.
I'm not saying .510" won't work.. it will certainly but you may find .512" may prove to be more accurate. The 12,7x44R is a very capable cartridge moreso for accuracy than power. Its not a hugely powerful cartridge overall. Your bullets should be softer rather than harder. An alloy of 30 parts lead and 1 part tin or 30:1 ratio is about right for black powder bullets. The bullets must obturate (expand) in the bore and harder alloys make that impossible.
I notices, there must not be any empty room being left inside the loaded cartridge between the bullet and the black powder, thus this has to be filled with a wad or card shims. What is the size of the internal diameter of the cases when sized?
Yes, no air space in a black powder cartridge between the powder and bullet. This is very important for safety.
A 1/2" diameter cardboard wad card like a waxed milk carton will do just fine. It needs only to fit in the inside of the cartridge case. So a perfect 12,7mm is perfectly fine.
However, you will have NO air space:roll:. Using a 450 grain bullet or even a 350 grain bullet with 65 grains or more, even 60 grains, will leave no room for the bullet. The powder must be compressed with a special brass or aluminum plug called a compression die to push the powder down into the case, compressing the powder into a hard nearly solid plug of powder. Very nearly like Pyrodex pellets only they will not come out of the cartridge case easily. The card wad is then inserted into the case and the bullet is seated onto the card wad. Even using a compression die you may still have to seat the bullet down with some force to compress the powder further in order to seat the bullet adequate enough to fully chamber in the rifle. There is no caming force in chambering of a rolling block so the cartridge must chamber easily with your fingers.
I ordered some .50 Alaskan cases to convert them. you mentioned those on your site as quite promising, but also that they require inside reaming.
I need to update that information. Some rifles will accept a .50 Alaskan case cut and trimmed to the correct length without any further effort. Some rifles. Not all of them. Of the rifles I had the only one that would accept the .50 Alaskan case was the 1885 artillery carbine.
If your rifle does not accept the .50 Alaskan cut off and trimmed to 1.730" (or there abouts) there is another remedy but you may not want to do it. That is to polish out the chamber slightly in order to accept the .50 Alaskan case. On a collectable rifle this may not be a good idea. But on a cut down sporter there's little to loose by doing this. If you intend on keeping this rifle forever.... then you might think about having a gunsmith do this minor polishing after you supply him with a couple dummy cases with a bullet seated but no powder or primer.
Again, you may find your rifle will accept the .50 Alaskan case. Or it may not. I've used .348 Winchester cases exclusively once I found most of my rifles would not take the .50 Alaskan. I was not happy about that as I had purchased 150 of the Starline .50 Alaskan cases in a group buy but they were still expensive.
How do you do this and to which size one has to ream?
I do have a Sinclair neck reamer for outside turning necks, and was wondering or, if I reamed the outside to the wanted wall thickness for 10 or 15 mm and after this,annealed and fire formed the cases I would have the same effect?
I can't really answer this as I've not had to do it. I have my own feelings about trimming the neck area of a straight case like you say in order to achive full chambering. Upon firing the "step" that is created where the turned case meets the unturned case has no support against the chamber wall. This could create a stress crack. This is just my feeling on this particular practice. If this proves to be nessessary then the inside reaming to reduce case wall thickness may be the best approach. However I've not done this practice so you'll have to do some experimenting of your own. I would start at reducing the inside diameter no more than .004" to begin with.
Prior to about 2000 in the U.S. there were few of these Swedish rolling block rifles coming into the U.S. We had no information about them. It was not such a big mystery to figure out and we got some help from Per Kindbloom in Stockholm who is a well known dealer and blackpowder shooter in Sweden. His English was not so good but we managed to communicate well enough. Thus we began learning as more of these rifles came into the U.S. and they are still coming in dwindling numbers now in 2008.
There are some basic discoveries found in loading other blackpowder cartridges that will help with the 12,7x44R. One such book indirectly related by an outstanding piece of work is "Loading Cartridges for the Original .45-70 Springfield Rifle and Carbine" by J.S. and Pat Wolf. The husband now deceased with the wife carrying on with the publishing and marketing of this book. It is simply the best book of its type on experimenting with loading protocal for a straight wall blackpowder cartridge. The use of magnum primers with black powder is one factor. Another is enlarging the primer flash hole to .096". This is just an example of what may be gleaned from such a book even though it does not relate directly to the 12,7x44R cartridge.
I have in my cartridge collection one single original rimfire 12,17x42R rolling block cartridge. In the U.S. it is extremely rare. In Sweden it is also very rare. I got lucky having a good contact in Sweden for a number of years to aquire this single sample. Having it allows me to measure directly an original cartridge intended for this specific rifle.
If anyone has corrections or additions to share pertaining to this cartridge or rifle please feel free to add them in this thread.
Dutch
www.rebooty.com/~dutchman
Swedish Mausers
reference:
http://www.rebooty.com/~dutchman/12744r.html
http://www.rebooty.com/~dutchman/6774.html
http://www.rebooty.com/~dutchman/1885carbine.html
http://www.rebooty.com/~dutchman/1867sporter.html
Pay close attention to this page:
http://www.rebooty.com/~dutchman/RBfailure.html
I ordered a Lee bullet sizer/lube kit in .510
Generally, .512" is what I've found when the grooves are measured with the inside knife edge of dial calipers. Not all rifles are going to be the same but we've found some a little more into .514". The U.S. cartridge of the 1868 period was the .50-70 Government. The bullet was .515" with 70 grains of Ffg powder and a 450 grain bullet. The 12,7x44R is a smaller version, narrower in the cartridge head, a little shorter in length and the original bullet was 345 grains with 75 grains of black powder. In the U.S. we would refer to such a cartridge as this:
.50-70-450
.50-75-345
If you have access to a lathe you can polish out the interior of the Lee sizer die with 320 grit - 400 grit - 600 grit then crocus cloth lubricated with a watery petro like WD40 if you have that in Holland. Kerosine or diesel would also work but with fine grits of emery cloth you need a thin lubricant, not a viscous oil.
I'm not saying .510" won't work.. it will certainly but you may find .512" may prove to be more accurate. The 12,7x44R is a very capable cartridge moreso for accuracy than power. Its not a hugely powerful cartridge overall. Your bullets should be softer rather than harder. An alloy of 30 parts lead and 1 part tin or 30:1 ratio is about right for black powder bullets. The bullets must obturate (expand) in the bore and harder alloys make that impossible.
I notices, there must not be any empty room being left inside the loaded cartridge between the bullet and the black powder, thus this has to be filled with a wad or card shims. What is the size of the internal diameter of the cases when sized?
Yes, no air space in a black powder cartridge between the powder and bullet. This is very important for safety.
A 1/2" diameter cardboard wad card like a waxed milk carton will do just fine. It needs only to fit in the inside of the cartridge case. So a perfect 12,7mm is perfectly fine.
However, you will have NO air space:roll:. Using a 450 grain bullet or even a 350 grain bullet with 65 grains or more, even 60 grains, will leave no room for the bullet. The powder must be compressed with a special brass or aluminum plug called a compression die to push the powder down into the case, compressing the powder into a hard nearly solid plug of powder. Very nearly like Pyrodex pellets only they will not come out of the cartridge case easily. The card wad is then inserted into the case and the bullet is seated onto the card wad. Even using a compression die you may still have to seat the bullet down with some force to compress the powder further in order to seat the bullet adequate enough to fully chamber in the rifle. There is no caming force in chambering of a rolling block so the cartridge must chamber easily with your fingers.
I ordered some .50 Alaskan cases to convert them. you mentioned those on your site as quite promising, but also that they require inside reaming.
I need to update that information. Some rifles will accept a .50 Alaskan case cut and trimmed to the correct length without any further effort. Some rifles. Not all of them. Of the rifles I had the only one that would accept the .50 Alaskan case was the 1885 artillery carbine.
If your rifle does not accept the .50 Alaskan cut off and trimmed to 1.730" (or there abouts) there is another remedy but you may not want to do it. That is to polish out the chamber slightly in order to accept the .50 Alaskan case. On a collectable rifle this may not be a good idea. But on a cut down sporter there's little to loose by doing this. If you intend on keeping this rifle forever.... then you might think about having a gunsmith do this minor polishing after you supply him with a couple dummy cases with a bullet seated but no powder or primer.
Again, you may find your rifle will accept the .50 Alaskan case. Or it may not. I've used .348 Winchester cases exclusively once I found most of my rifles would not take the .50 Alaskan. I was not happy about that as I had purchased 150 of the Starline .50 Alaskan cases in a group buy but they were still expensive.
How do you do this and to which size one has to ream?
I do have a Sinclair neck reamer for outside turning necks, and was wondering or, if I reamed the outside to the wanted wall thickness for 10 or 15 mm and after this,annealed and fire formed the cases I would have the same effect?
I can't really answer this as I've not had to do it. I have my own feelings about trimming the neck area of a straight case like you say in order to achive full chambering. Upon firing the "step" that is created where the turned case meets the unturned case has no support against the chamber wall. This could create a stress crack. This is just my feeling on this particular practice. If this proves to be nessessary then the inside reaming to reduce case wall thickness may be the best approach. However I've not done this practice so you'll have to do some experimenting of your own. I would start at reducing the inside diameter no more than .004" to begin with.
Prior to about 2000 in the U.S. there were few of these Swedish rolling block rifles coming into the U.S. We had no information about them. It was not such a big mystery to figure out and we got some help from Per Kindbloom in Stockholm who is a well known dealer and blackpowder shooter in Sweden. His English was not so good but we managed to communicate well enough. Thus we began learning as more of these rifles came into the U.S. and they are still coming in dwindling numbers now in 2008.
There are some basic discoveries found in loading other blackpowder cartridges that will help with the 12,7x44R. One such book indirectly related by an outstanding piece of work is "Loading Cartridges for the Original .45-70 Springfield Rifle and Carbine" by J.S. and Pat Wolf. The husband now deceased with the wife carrying on with the publishing and marketing of this book. It is simply the best book of its type on experimenting with loading protocal for a straight wall blackpowder cartridge. The use of magnum primers with black powder is one factor. Another is enlarging the primer flash hole to .096". This is just an example of what may be gleaned from such a book even though it does not relate directly to the 12,7x44R cartridge.
I have in my cartridge collection one single original rimfire 12,17x42R rolling block cartridge. In the U.S. it is extremely rare. In Sweden it is also very rare. I got lucky having a good contact in Sweden for a number of years to aquire this single sample. Having it allows me to measure directly an original cartridge intended for this specific rifle.
If anyone has corrections or additions to share pertaining to this cartridge or rifle please feel free to add them in this thread.
Dutch
www.rebooty.com/~dutchman
Swedish Mausers