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I just picked up a taylors armi sport (chiappa)sharps shorter rifle. I have been trying to find the safe load pressures for this rifle. I have read 18000 psi up to 29000 psi depending on the source. Does anyone here know what the safe shooting limits are for stress rifles?
The action is strong but some of the replicas duplicated the large firing pin of the original Sharps. Heavier loads will push the primer back into the FP hole and cause problems. I have seen one that was locked up because the primer shoved far enough that the block would not drop.
Thank you
Just bought a Lyman/Pedersoli Sharps. It had been sitting around the LGS29 for a while. Per the manual I should use trapdoor loads. The Italians proof tested to 2000bars which if I believe Lyman is about 29000 cup/psi. Basicly we have 21st century trap door rifles. We can hunt Bison but not Cape Buffalo.
I’ve owned several Pedersoli Sharps replicas. They’re rated at 27,000psi tops.
NSB what is your source for 27000psi? My manual dated 2013 lists 45/70 at 29007psi. Manual also says reload to trapdoor standard. Will probably load to a lower trapdoor level. I am old and don't like recoil anymore.
I shoot trapdoor level loads in mine. I enjoy shooting it more with those loads.
Looks like CIP max pressure for 45-70 is 2200 bar or 31908.3 PSI (according to google who I let do the math for me).
https://bobp.cip-bobp.org/uploads/td...en-page112.pdf
Interesting, Norma publishes data for 58,000 psi loads for the Ruger No 1 rifle. 500 grain slug at 1800 fps, don't think I would want to be standing in front or behind one of those!Quote:
Originally Posted by kenton
A Ruger No 1 is in a completely different league than the Sharps as far as strength. It is generally agreed there are three levels of strength in 45-70 rifles. Level 1 is Trapdoor, Sharps and other early single shots. Level 2 is 1886 Winchester/Browning and Marlin 1895s. Level 3 is normally considered to be Ruger No 1s and modern single shots. Level 1 is the weakest and Level 3 is the strongest. There are other rifles in each of the groups, but you get the idea.
Bill
In all my larger case capacity BP era rifles I use IMR4198 or H4198 smokeless powders. The pressures are way below even what BP pressures are, and my load for the .45-70 with a 480 gr. bullet at 1350 fps is under 12,000 psi chamber pressure according to my ballistic program. It's very comfortable to shoot, and accurate also.
What would you like to do with it? For paper targets or medium game you may never have the need to exceed Trap Door loads.
Another thing about the chiappa 74's is that they don't have the dovetailed cover over the back of the firing pin like the originals, pedersoli and the Montana built ones do. This prevents a face full of gas if a primer burns through. You really don't want to magnumize a .45-70 it will do everything you want with trapdoor pressure loads.
IF YOU SHOOT BLACK YOU CAN'T OVER PRESSURE, IF YOU SHOOT A BLACK SUBSUITE YOU WOULD HAVE TO WORK VERY HARD TO OVER PRESSURE, IF YOU SHOOT SOFT LEAD YOU DO NOT NEED TO GO OVER 1200 fps AND YOU WILL HAVE ACCURT LOADS> YOU SHOOT HARD CAST OR JACKED BULETS, THAT RIFLE WAS INATALLY NOT DESIGNED FOR WHAT YOU ARE DOING>>
My goal is to be around 1300-1400 fps with cast boolits, not Hardcastle in the 405 to 535 grain sizes. General shooting with the 405 and get into some long range stuff with the 535 at some time.
I emailed Pedersoli and got a response that way. Odd that they’d put an “odd” number in the manual of 29,007psi. How did they cut it that close? 007….really? Like seven psi could really make a difference.Quote:
Originally Posted by Duckiller
In the past few decades I've had Many offshore Sharps and rollers, all Pedersoli. They are strong and they are accurate. I just picked up a Cimarron '74 Sharps (Chiappa, Armi Sports) and both Cimarron and Chiappa specify that smokeless loads need to be in the trap door realm. I don't do smokeless with any of these guns and usually run the .45-70s with at least 80 grains of Swiss 1-1/2f underneath a PPB. Never a problem or issue. Stick with the black. Save the white devil dust for the Rugers and Henrys. :)
https://i.imgur.com/0ejtGjC.jpg
Come now. Surely you trust another Government: Browning's 1911, right?Quote:
Originally Posted by FrankJD
I tend to trust a 30 Gov for alot also.
Is your chiappa proofed for smokeless?
Chiappa primed cartridge Sharps are good for trap door loads with "smokeless black powder" (Pyrodex, etc), or with real smokeless powder such as AA5744. This means no Lever gun or Ruger #1 loads. The old Lyman #49 & Cast Bullet manuals clearly identify these three levels of loading for the .45-70 cartridge.
From the Chiappa Sharps 1874 pamphlet ...
All our guns are tested in the Armi Sport facility. To guarantee the gun is safe, it is sent to the National
Proof House of Gardone Val Trompia – BRESCIA – ITALY - for proof testing.
The Proof House tests the firearm with heavy loads then checks the barrel, chamber and headspace to
make certain the firearm is safe for use with standard factory ammunition.
The National Proof House will put their markings on the gun, according to the Italian law, certifying the
gun is qualified and can be sold.
As to reloaded cartridges, we wish to point out that the Sharps rifle has been designed and manufactured for use
with black powder and similar (Pyrodex) only. As far as the loading is concerned, we suggest to use a loading
manual from specialized companies (for instance RCBS, Lyman, etc)
A NOTE ABOUT HISTORICAL FIREARM DESIGNS
Armi Sport proudly manufactures finely crafted replica
firearms reproducing famous historical weapons. These
firearms are manufactured using leading edge machinery
and high quality modern materials. They are faithful
reproductions of firearms originally designed in the
nineteenth century; therefore, if you choose to own or use
historical firearms you should be aware that, along the
one hundred or more years past, there have been
significant advances in firearms design and safety. Armi
Sport manufactures these guns not as state of the art
firearms, but as historically significant firearms for the
collector. It is vital that the user be familiar with his
firearm and possible safety risks that may be present in
the design. Most significantly, the user should realize that
the designs of safeties - or even the presence of adequate
safeties - vary significantly on historical designs and do
not offer the protection against accidental discharge that
modern firearms safeties achieve.
Similarly, any firearm that is designed to be fired using
black powder (or Pyrodex) has basic risks not found in
modern cartridge firearms. Black powder is a dangerous
explosive and has to be used and handled with extreme
caution. The slightest miscalculation or carelessness with
black powder firearms can result in serious injuries to the
user
The original 45/70 was designed to shoot through a horse at 200 yards, I’m told. Not sure why you would need more than that, unless there’s a scourge of mastodons in your area.
Long range with the 535 grain boolits can be done at around 1300 fps (not by me... yet). Lyman #50 shows 28 grains of 5744 under a 535 grain boolit as a max load for Trapdoors. Your Sharps probably doesn't weigh as much as my roller. If I was you, working with that rifle, I'd try 24-26 grains (23 is the starting load), see how it feels and how it shoots.Quote:
Originally Posted by Dtdk
AA5744 is arguably the better smokeless powder for trap door loads as it was made for loading these old cartridges and yielding a better fill within the case.
29007 psi converts to 20,000 newtons per square centimeter - wonder if they gave you a metric conversion figure?Quote:
Originally Posted by NSB