What is the difference other than the amount of BP in the casing? I would assume that the casings would be different sizes ie the 45-120 would be longer and the rifle would be built to handle the higher pressures. Could you take a 45-120 casing and rifle and load it to 45-70 specs and have it act as a 45-70 but have the versatility to load up to a 45-120 if you wanted to?

As you can tell I know squat about these.

Less powder in that long 120 case will cause problems.  You'll need to fill the case with as much powder as possible for the load and "pad out" the rest with filler.  If all that powder is forward toward the bullet when you squeeze it off, there could be PROBLEMS (pressure through the roof).

If you are looking to "download" a 120 why don't you just stop with a .45/90???

There isn't much of a pressure difference between the 120 and the 70 when using BP.  All BP loads are 100%, compressed.  Modern cases that are solid head will not allow 70/120 grains to be used.  Older cases with balloon heads can but must NOT be used for anything but BP.

Yes, you CAN load 70 grains of BP in a 120 but you must use a filler, usually cornmeal or farina.  Use a card wad over the powder to keep them from mixing.  Use an old case to cut them from cardboard.

On smokeless, you can load anything in a 120 but you must follow the pressure limitations as there are .45/70 loads for more modern actions (lever etc) that can cause damage.  NEVER use data for Ruger #1/#3 rifles in any older/replica action.

Lyman's Reloading Manual has all you need.

Damn, you gotta love this place.


I don't even have the gun that is in question, but I'm getting an urge to check one out now!

Loads of info here:


www.bpcr.net/site_docs-results_schedules/documents/bp_cartridge_reloading_dick_trenk.htm

Quoted: Damn, you gotta love this place. I don't even have the gun that is in question, but I'm getting an urge to check one out now!

Well............if ya gotta look at black powder porn :

CAUTION.......Put CCs out of reach before clicking

 Here is my Shiloh Sharps 50-140
 The second number of a bp cartridge generally refers to the grains of powder which are used.
 I generally load 136 gr. of FFG for accuracy.
 When you are loading close to the top capacity, a drop tube of at least 24 " is what's needed to settle the powder.  Without a drop tube your are compressing the powder with the bullet which leads to broken grains of powder and a drop off in accuracy, and sometimes a bulged case.
 
 Black powder is a blast on the range.  There is nothing like a cloud of smoke drifting over other shooters who generally are like .

 Someday I'd love to pick up a 45-90.  It would be a bit more economical that what I'm now shooting.

Quoted: i182.photobucket.com/albums/x167/50-140/shilohsharps003.jpg  Here is my Shiloh Sharps 50-140  The second number of a bp cartridge generally refers to the grains of powder which are used.  I generally load 136 gr. of FFG for accuracy.  When you are loading close to the top capacity, a drop tube of at least 24 " is what's needed to settle the powder.  Without a drop tube your are compressing the powder with the bullet which leads to broken grains of powder and a drop off in accuracy, and sometimes a bulged case.    Black powder is a blast on the range.  There is nothing like a cloud of smoke drifting over other shooters who generally are like .  Someday I'd love to pick up a 45-90.  It would be a bit more economical that what I'm now shooting.

How's the recoil ?  

Quoted: i182.photobucket.com/albums/x167/50-140/shilohsharps003.jpg

Thing of beauty right there

Quoted: Quoted: i182.photobucket.com/albums/x167/50-140/shilohsharps003.jpg   Thing of beauty right there

 Thank you

 As to the recoil, when stoked with 132-135 gr. FFG recoil is a lot of smoke, gentle push.  
 When I get up to 138,-140gr., a good crack occurs, recoil becomes close to a 20ga shotgun.

I have a 45-70:


And also a 45-90:


Here is a pic with cartridge comparisons, .223/45-120/45-90/45-70:


My buddy has a 45-120 he had the hardest time trying to find a load that would shoot accurately in it.
I really enjoy my 45-70 but with big heavy bullets I just couldn't get the powder load I wanted in it so I bought the 45-90.
The 45-90 is now my favorite BPCR!

I cast my own 532 grain 1:20 bullets and load a .3" compressed charge of 85 grains of Goex Cartridge black powder.

These things are FUN to shoot!!!!

shot a Shiloh once theres No other comparison the build was Excellent the Accuracy with the handloads was beyond what I would have ever expected

Sweet rifle

www.shilohrifle.com/