i was watching quigley down under this evening.  and yes while i know hollywood doesn't get things right it did make me wonder about the caliber rifle he was using.  well not specifically that caliber but the interchangability of it with other cartridges.  now i understand that .45-70govt was packed with 70gr of powder and that the cavalry at the time was using .45-55govt.  now i would guess that means it has 55gr of powder in the casing.  but were .45-110 and .45-120 just higher pressure rounds or did they have longer cases?  in either case, would a rifle chambered for .45-120 have been able to fire the smaller cartridges?

You have to remember that the cases/ammo of the time was loaded with black powder.  As you figured out, the first number is the cal, and the later the amout of Black power. In regards to the 45-70, the actual working pressure of the round is only around 18,000 psi, and the 45-120 just a little over 20,000psi. As for case length, yes themore powder, the longer the case since these were straight wall cases.

To take this into the now future, the only round that was converted to smokless powder was the 45-70 goverment, but still loaded to the old BP working pressures. Funny part is now with the use of modern steel and smokeless powder, a rifle in say 30 win mag has working pressure of around 50,000 psi.

Bottom line is the steel of the time would only safely retain around 25,000 PSI before blowing apart ,and this really limited the amount of BP that could be used.

ok let me see if i get this right--a springfield trapdoor cavarly carbine in .45-55 would not be able to chamber a standard .45-70 round?  but the -55, -70, -110 would all be able to be shot out of a sharps chambered for .45-120?  also doe anybody have case dimensions or at least lengths?

Since a 45-55 was an issued round it used the same case as the 45-70. I could be mistaken but I think the smallest 45 series rifle case of that time was the 45-60. As for case lengths, here are the lengths as stated in the Accurate powder manual.
45-70 - 2.105in
45-90 - 2.400in
45-110 - 2.875in
45-120 - 3.250in
 The 45-70 has a .505in head diameter, all the others are .506in All these cases have the same .608in rim diameter.
Could you fire a 45-70 in a 45-120 ? I guess you could but the bullet would have to travell over an inch before it even contacted the throat. Not the best way to assure accuracy and what about case stretching ?

You might enjoy this:

www.ar15.com/forums/topic.html?b=1&f=5&t=415492

BTW, my rifle is marked ".45 - 2 1/10", the length of the .45-70 case in inches.

Quoted: Since a 45-55 was an issued round it used the same case as the 45-70. I could be mistaken but I think the smallest 45 series rifle case of that time was the 45-60. As for case lengths, here are the lengths as stated in the Accurate powder manual. 45-70 - 2.105in 45-90 - 2.400in 45-110 - 2.875in 45-120 - 3.250in  The 45-70 has a .505in head diameter, all the others are .506in All these cases have the same .608in rim diameter. Could you fire a 45-70 in a 45-120 ? I guess you could but the bullet would have to travell over an inch before it even contacted the throat. Not the best way to assure accuracy and what about case stretching ?

ok i thought it was something like .38spl and .357mag.  i guess in the days of black powder though they had to add that much case length in order to get more powder in there to get the extra performance needed.  thanks guys.

The trapdoor carbine was chambered for the standard 45-70 and would chamber the same round as the rifle. The problem was it was very uncomfortable to shoot with the fullpower loads, thats why the powder charge was reduced to 55g. It was not technically a different round. The 45-90 and 45-120 were just elongated 45-70 cases. The 45-60 you refer to was a completely different round, being a bottlenecked cartridge designed to fit in the shorter action Winchester 1876.

I have an 1886 Winchester in 45-90, yes they still make them.  It will shoot 45-70, 45-85 and 45-90 and it does shoot 45-70 with a 405gr bullet into about 1.5 inches at 100yds.  45-70 is shorter and 45-85 has a heavier bullet but is the same as 45-90.  45-90 was loaded with smokeless powder as the 45-90 Express and was sold into the 1930's.  Case head diameter was the same. Length and bullet weight was different, guns that shot heavy lead bullets (400gr plus) will not normally shoot lighter (330 gr or less) bullets very well.  They had different rifling as well.  Cases using the original case head diameter from 45-70 were made all the way out to 45-120.

45-70-405 means 45 caliber, 70 grains of blackpowder, 405gr bullet

Now, here is where it gets fun. Sharps calibers have different shapes and case head sizes than Winchester or government calibers.  Modern Sharps are chambered for 45-70 Government, the original military caliber.  Be careful shooting anything 19th century, they are a dizzying array of calibers from several makers that look similar.  They can vary considerably in bullet weight and performance.

Quigley could have shot anything from 45-70 to 45-120, the 45-70 should have had about 3/4 an inch of jump, while not ideal it will work in a pinch for shooting those pesky aussies.

Clear as mud, right?

Quoted: Clear as mud, right?

god bless standardization of measurements etc

For what it's worth the Quigley rifle was 45-110. The Sharps company never chambered a rifle in 45-120. I've been shooting Sharp's for 15 years.( 45-70, 45-90, 45-110. The 45-110 is a real hoot to shoot with a 540gr. bullet on top of 105 grains of blackpowder.

wasn't the NRA giving away replicas of the round when you re-upped last year?

Quoted: For what it's worth the Quigley rifle was 45-110. The Sharps company never chambered a rifle in 45-120. I've been shooting Sharp's for 15 years.( 45-70, 45-90, 45-110. The 45-110 is a real hoot to shoot with a 540gr. bullet on top of 105 grains of blackpowder.

Ouch.

Just

Ouch.


I have a Pedersoli Heavy Target (13lb), and it's pleasant to shoot 530gr bullets on top of 67gr of FFg.  Pretty accurate, too!

Quoted: You might enjoy this: www.ar15.com/forums/topic.html?b=1&f=5&t=415492 BTW, my rifle is marked ".45 - 2 1/10", the length of the .45-70 case in inches.

The contemporary (i.e., old time) way of specifying cartridges was by caliber and case length, as your rifle is marked.  The .45-70 stuff came along later.  It was probably thought up by the guys who dreamed up "Main Battle Rifle" before they ran out of good ideas.

As stated before the Gov. Carbine loads 45-55 were used in the same length cases as the 45-70 rifle loads.  They were loaded with a wad between the base of the bullet and the powder to take up the space and then found that the wad was unnecessary and eliminated it all together and just did not compress the powder as much.  RnR  

so .45-55 was in a manner of speaking just .45-70 -p.