45-120 -versatility ?

[ascast]

Hope this category is best. Got into a discussion about the 45-120. Question is can you use it as a 45-70? just seat bullets way out ?
It looks like the base dia. would be OK. Or maybe a 45-90? It is not a popular cartridge and brass is way too expensive.
so school me up
thanks

[beshears]

I would expect the bullet to bump to 50 cal in front of case then be squeezed back down to 45 cal at throat. I would expect terrible leading and no accuracy. Find a few cases and reload case at bench. Reprime, powder and wad and seat bullet by hand in the case.

[NSB]

I’m confused by your question. 45-120 brass is longer than 45-70, so it won’t fit a 45-70 chamber. Seating the bullets “way out” would only make the round longer yet. I have seen the question asked, “can I shoot 45-70 in a 45-90 or 45-120 gun” and the answer is yes, but the jump to the lands may affect accuracy. The 45-70, 45-90, and the 45-120 are basically the same case but in varying lengths. Using black powder requires a lot more powder than smokeless does to achieve even closely the same velocities so the cases are longer. A 45-70 chamber with smokeless powder will easily surpass the velocity of black powder in a 45-90 or 45-120 chamber with black powder.

[Don McDowell]

The 120 case is an inch and a half longer than the 45-70 case. The bullet would expand to chamber diameter and then be swaged back to bore/groove diameter, leading would be ferocious the velocity would likely be miserable, and accuracy most likely nonexistent. This isn't a 38/357 thing.If you have a 120 either spend the money for proper cases or have it rebarreled.

[greyhawk]

The 120 case is an inch and a half longer than the 45-70 case. The bullet would expand to chamber diameter and then be swaged back to bore/groove diameter, leading would be ferocious the velocity would likely be miserable, and accuracy most likely nonexistent. This isn't a 38/357 thing.If you have a 120 either spend the money for proper cases or have it rebarreled.

Don is it possible to set the barrel back/ shorten the chamber ? or are the action threads too big for that manouver ?

[Mr.doug]

Don’t know the action but if is a straight barrel and no tulip like a Shiloh it could be set back
Re-threaded and rechamberd. The hanger for the forend will also have to be moved

[country gent]

Setting the barrel back would require recutting the chamber rim and extractor. While the45-120 and 45-70 are considered straight walled there is a slight taper to them. The other is getting the reamer pilot into the bore solid enough wen starting out. The 45-70 reamer may start to cut lightly before the pilot engages the bore. In a lathe with a good float this may not be a problem by hand it may cause some problems

[Don McDowell]

Don is it possible to set the barrel back/ shorten the chamber ? or are the action threads too big for that manouver ?

As Mr Doug and country gent have stated it would be possible, but depending on the type of barrel. It would also be a better outcome if a chamber cast was made and then a proper reamer made and someone really good at lathe set up. It would be something needing to be done by a gunsmith and not a gun parts exchanger.
In the end a rebarrel would be the better option, IF you don't want to buy the proper cases in the first place.

[Mr.doug]

I agree with don it would be better to rebarrel it especially if it’s 30” long. Save the old barrel
2 barrel set or may be able to less it off later . Or sell the gun and get a cartridge u prefer to shoot.
Just my 2 cents.

[K43]

You'd be money ahead to either buy some 45-120 brass or sell the rifle and buy another in a commonly available cartridge like 45-70 or 308.

[ascast]

thanks to all - you have confirmed my thoughts on the subject. The conversation came from a friend who has found one for sale on the lower end of the price range. I have tried to talk him off of it for all above mentioned. By the time it gets "fixed" he should have bought a new 45-70.
I will refer him to this thread.
thanks again to all.

[Don McDowell]

Well if it's cheap enough, then buying the proper brass and a couple of cases of 1f might not be all bad. And if it turns out he doesn't like it, another 1000 into it and it's got a 45-70 or 90 barrel.

[greyhawk]

As Mr Doug and country gent have stated it would be possible, but depending on the type of barrel. It would also be a better outcome if a chamber cast was made and then a proper reamer made and someone really good at lathe set up. It would be something needing to be done by a gunsmith and not a gun parts exchanger.
In the end a rebarrel would be the better option, IF you don't want to buy the proper cases in the first place.

I just bought a Shiloh in 40/90 straight (estate deal) it came with a plentiful supply of Brass.

Seems like a hundred cases would be his best option so long as he can shoot the 120 ok

My gun is ten pound and tolerable to shoot, (getting older and softer, fun might turn into punishment ten years down the road!)

I wouldnt be interested in a 120 at that weight - had that opportunity years ago and a good friend talked me out of it

[Sgt H]

Assuming thee present barrel is good setting it back would be less than a rebarrel. Probably not much more than 100 45-120 cases given the price of those. The 45-120 case is 1.15" longer than the 45-70 not 1.5".

[Don McDowell]

I just bought a Shiloh in 40/90 straight (estate deal) it came with a plentiful supply of Brass.

Seems like a hundred cases would be his best option so long as he can shoot the 120 ok

My gun is ten pound and tolerable to shoot, (getting older and softer, fun might turn into punishment ten years down the road!)

I wouldnt be interested in a 120 at that weight - had that opportunity years ago and a good friend talked me out of it

I campaigned a 10 lb 40-90 bn Shiloh for 1 season. It shoots well, but the recoil and muzzle blast from the thing takes a toll on you by the end of a match, even a gong match. Can see why the ODG's liked the cartridge for hunting purposes. Have a neighbor with the 90 straight that he's used to shoot a couple of buffalo with, but he only has maybe 50 cases for it.
Back in the mid 1970's I spent quite a bit of time with a C Sharps 120 rocky mtn buttplate and all, fun rifle to shoot, but like a lot of the large cased sharps it consumes an awful lot of powder every time that hammer drops.

[ascast]

I have not seen this rifle, but said to have a 34 inch barrel, like new. Semi crescent butt plate. I'm guessing it cost $900-1000. I think that is just a bit more than I would spend to correct someone elses mistake.

[Don McDowell]

That butt plate is going to limit the shooting to either sitting or offhand, fine for a short plinking session or a couple of rounds hunting. But you're right even a rebarrel to some other cartridge won't help much, best to find something more goodder

[M-Tecs]

I have not seen this rifle, but said to have a 34 inch barrel, like new. Semi crescent butt plate. I'm guessing it cost $900-1000. I think that is just a bit more than I would spend to correct someone elses mistake.

You did not state what brand or model it is or intended usage?

If the $900-1000 is correct I would jump on it if it was an 1874 Shiloh or C. Sharps if only to flip it. If it's one of the lower quality 1874 clones that more than I would be willing to pay even if exactly what I was looking for.

If you just want it for shooting light smokeless loads the large case is far from ideal but not impossible. The 45/70 is a much better option for smokeless.

[greyhawk]

I campaigned a 10 lb 40-90 bn Shiloh for 1 season. It shoots well, but the recoil and muzzle blast from the thing takes a toll on you by the end of a match, even a gong match. Can see why the ODG's liked the cartridge for hunting purposes. Have a neighbor with the 90 straight that he's used to shoot a couple of buffalo with, but he only has maybe 50 cases for it.
Back in the mid 1970's I spent quite a bit of time with a C Sharps 120 rocky mtn buttplate and all, fun rifle to shoot, but like a lot of the large cased sharps it consumes an awful lot of powder every time that hammer drops.

Don
appreciate your interest
Theres a bunch of other stuff mixed up in this 40/90 deal - ex owner was a mate, dedicated member of our local BP club, cancer took him out just before easter, I kinda wanted one of his guns (plenty to choose from) . Being the cheapskate I am, a Shiloh over the counter down under (much as I have drooled about owning one) would be way outside what I would be prepared to pay. I had too many big guns already (Browning 71 - 348, Italian sharps - 45/70, Chiappa 1886 - 45/70, and a Uberti 1876 in 45/75) The backyard dealer who had charge off the stuff is a scoundrel looking to rip off the family beneficiaries - poor descriptions , crappy photos, wouldnt let us inspect before bidding - so I put in a bid lowish but not insulting, conditional on all the accessories to go shoot (thinking at this point it would be a 40/65 - sensible eh! - but I am not really known for sensible) Anyway am quite happy with the deal the way its turned out - I like the challenge of making something difficult work, so that part will be fun and I will get it done. The collective wisdom from this forum (yourself and a few others) will help for sure.

Powder consumption not a problem, we make it, and that gives me some options others maybe dont have.

Recoil -- yeah -- I shot it last week with a 300grain RCBS over 75 grains of FFg = good result on paper (only had the barrel sights though so not a true test) I reckon that load was about on par with the .348 and noticeably less than the other three listed - a good plinker / club load
Also did a 400 grainer over 80 grains ? getting up a bit but still quite tolerable (about on par with my 45/70 sharps - 535 grain boolit)
Plenty room in that long case to dink around with the wad column (lube cookies etc)
Have a range of Good molds from 300 to 450 grain
Looking for a decent tunnel front sight for it at the moment

Getting it sorted will be fun - realistically I proly only shoot two or three serious matches with it per year