Pretty Sure My Sharps Isn't a 45-120

[harringtondav]

Per my post from a few years ago I'm still working on firing my Dad's 45-120. ...at least he thought that's what he owned based on his meticulous 1960's notes.
Taking his word as gospel I ordered some Bertram brass and loads. ....got tired of finding someone who could get Norma brass.
Empty brass fit just fine. Loads bottom out long. I measured the distance from the receiver face to the start of rifling, not the counter bore face. Roughly 3.28". The cartridge is about .68" long, measures 3.65" long.
Clearly the gun is chambered for a shorter cartridge. Please help and tell me the correct size.
Thanks, Dave

[Don McDowell]

Might want to get some cerrosafe and do a chamber cast to measure the chamber length and throat length and diameter. Sounds like it may be a 2.6 or maybe a 2 7/8 chamber, but before you start sawing on the brass some good measurements need to be done.

[harringtondav]

Thanks DM. I bought a Lyman die set for the 45-120. Do you know if the brass taper angle is the same with the shorter brass?
Assuming it is, and the neck expanding and seating die can adjust down I'd like to use these dies once I figure out what I have.

[Castaway]

Don, I’d normally defer to your wisdom, but why wouldn’t the rifle be chambered in 45-120 if the brass fits? Depending on nose shape, the bullet may have to be seated more deeply into the case. If I load a Lee 500 gr Govt bullet in my Shiloh Sharps, the bullet only has 0.386” sitting above the case mouth. Any more and it just won’t fit

[HWooldridge]

That silver scratch on the bullet nose may be where the bullet is hitting the beginning of the rifling. You might need a smaller profile bullet.

[harringtondav]

I used a bore light to look at the chamber. I noticed the machined diameter where the cartridge centers (throat?) ended before the rifling, with a recessed clearance between. The cartridge length is 3.24", just short of the dist to rifling of 3.28". I'd have to seat the bullet nearly flush to close the breech.
I just calculated the distance from the rifling marks on the bullet, minus the distance it was long and came up with 2.63" from brass face to rifling.
Maybe that length corresponds to the correct cartridge size.

[scattershot]

“Empty brass fit just fine.”

Seat your bullet deeper or use a more tapered ogive.

[Woodtroll]

Comparing the two photos, it looks like the "loaded" cartridge case is sticking out quite a bit more than the distance from the cartridge mouth to the scuff on the bullet would imply. From your measurements and the fact that the empty brass slides all the way in, I think the brass matches the chamber length.

Is it possible that the chamber is a tight one and/or the bullet is oversized, so that the brass is jamming in the chamber before it is fully seated?

Good luck! I hope you get her shooting!

[indian joe]

“Empty brass fit just fine.”

Seat your bullet deeper or use a more tapered ogive.

If you cant get a chamber cast done - bell (flare) the mouth of an empty case and load it all the way home - might tell you something useful?

[Don McDowell]

Don, I’d normally defer to your wisdom, but why wouldn’t the rifle be chambered in 45-120 if the brass fits? Depending on nose shape, the bullet may have to be seated more deeply into the case. If I load a Lee 500 gr Govt bullet in my Shiloh Sharps, the bullet only has 0.386” sitting above the case mouth. Any more and it just won’t fit

Because it’s possible the sized brass coul fit right up the throat
It is possible to load a 2 7/8 case with 120 grains of powder if only going by load data that could be what he called 120
Chamber cast is the only way to know for sure

[Don McDowell]

Dave it is does turn out to be a 2 7/8 your dies probably work ok
But if it’s 2.6 either ha ego get another set or have your dies shortened

[Lead pot]

Do a chamber cast. That will answer most of your questions.
If you don't have cerrosafe melt down a candle and pour it in the chamber. Lightly oil the chamber push a rolled to patch or what ever ahead of the chamber and pour in the wax. let it cool and push it out with your cleaning rod with a patch on the jag.
This will let you measure the chamber.

[Kenny Wasserburger]

Measure the outside diameter of your loaded cartridge at the case mouth.

This will tell you much also measure the diameter of your bullet just ahead of the case mouth. If it’s over .450 you have bulged the bullet while seating the cartridge. A common nob mistake when first learning to load this lead bullets. You’re compressing the powder with the bullet upsetting it.

If an empty case 3.25 long fits the rifle. Then you’re are doing something wrong when loading the cartridge.

Kenny Wasserburger

[Minerat]

Why not insert a boolit in the chamber until it just touches the lands? Then use a caliper to measure from the bullet base to the breach face. Then add that measurement to the boolit length and that would give you the max cartridge length. Which could be compared to known measurements for the 120 to see if it matched.

The true measurement you need is from the first drive band to the base of the case but having MCL you could be close enough to get you an answer..

[harringtondav]

Cerrosafe looks easy enough. Will a compressed wad of cotton or cleaning patches work to block the bore?
But I think I already know the answer. I dug out an old box of 45-70 Govt. cartridges. 2.535"OAL. ...close to 2.6"
Second pic shows the 45-120 from rifling marks to breech face against 2.875". Looks like a no go.

[Don McDowell]

Yes a flannel cleaning patch and a Colton ball about an inch into the rifling will work
Kenny and Mine Ray have both given some good suggestions to look at doing before the chamber cast
But with no chamber or caliber markings on the barrel a good chamber cast will answer a lot of questions
Is that an original rifle or something your dad rebarreled?

[semtav]

Quickest way to find out. Is take a piece of brass that fits in it, fill it full of black powder, put a couple wads on top and fire it. You should be able to see what's going on then.

Or smokeless and cornmeal

[harringtondav]

Below is a scan of his notes on that very topic. Seems he owned a "Franken-Sharps" and knew it. But he was sure it was a 45-120.
He dabbled with the gun Nov and Dec 1963. He noted he had trouble getting the breech to close with Nonte-Taylor cases. He cast up Lyman 457191 bullets, but couldn't get the breech closed. His mold for the heavy patched bullet is also shown.
His last note in 1983 was on making grease lubricating patches. The gun stayed in the closet until I cleaned out his house in 1992.

If it turns out be a 45-70 all isn't lost. Those 45-70s are likely smokeless, but I can reuse the brass and bullets with the appropriate black powder charge. ....I'll be back for advice on those loads if the time comes.

[Don McDowell]

I'll about bet it has been chambered for the 3 1/4 case at one time, but it was with the tight paper patch chamber. Any bullet over .450-454 diameter isn't going to chamber. Unless it's one of the really short 300 gr express bullets.
You might see if you can get ahold of some .444 slicks and wrap them in 8 lb paper, if you don't have his mold. Over 120'ish grains of 1f powder a .060 fiber wad, a 1/16 grease cookie and a thin wad punched from wax paper or a playing card.
Neat old rifle to be sure.

[harringtondav]

I've made more measurements and assumptions on this. Please advise if I'm fixing to blow my face off.
-Chamber appears to accept a 45-90 WIN.
-My 45-70 Govt. loads are nearly ready to be made into 45-90's. The difference seems to be 20 grains more BP and seating the bullet to a 3.3" overall cartridge length.
-I can verify by pulling a bullet, resize and expand the empty case neck, and loose assemble to 3.3" If the breech block closes and a 3.3" cartridge comes out I'll assume I have a 45-90 FrankenSharps.
-45-90 original bullet was 300 grain, mine are 405 grain. Am I in the danger zone using this bullet?. On another forum shooters go over 500 gr.
-Assumption is my cartridges are BP which can be reused. I'll weigh on disassembly. 70 grains will be BP, less will be suspect.

If all these pass your sniff test, I'll have more questions before I try firing the beast. Paper patch vs. grease. Bullet size for either, etc.
Thanks, Dave