Gunnerboy
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All the load data that i can find for the 257 roberts is +p in the IMR 4350 powder can anyone tell me what a 40gr charge would rate in pressure, the load is for an old m93 mauser.
257 roberts NON +p load data
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rcmodel
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You must be looking for love in all the wrong places.
The Starting load data in all my manuals from Lyman, Hodgdon, etc, are less then 40,000 cup or PSI.
I could possibly figure it out for you if I knew what bullet weight you are using 40.0 grains IMR-4350 with.
But I don't, so I can't.
rc
The Starting load data in all my manuals from Lyman, Hodgdon, etc, are less then 40,000 cup or PSI.
I could possibly figure it out for you if I knew what bullet weight you are using 40.0 grains IMR-4350 with.
But I don't, so I can't.
rc
Certaindeaf
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GooseGestapo
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You didn't state what bullet weight, but with any bullet up to 120gr, that will be a safe load.
What actually constitutes a +P load will depend on the chamber in your rifle. Most sporters have more generous throats on the chambers and this typically lowers pressures. I had a Ruger M77MkII that was maxxed out with the Hodgdon non-+P loads. Anything hotter led to cratered primers and burnished case heads. It too was more accurate with the "classic" non-+P loads.
It liked IMR3031 powder, of all things.... with a 100gr bullet. It "gagged" on either H380 or H414, whereas my custom M98 loves both, and is "ambivalent" on the IMR3031 loads.... But it does have the so-called 3" chamber.
Go figure....!
I use the traditional load of 45.0gr of IMR4350 with a 100gr bullet (Sierra's are most accurate, Hornady's best hunting bullet...) for about 2,950fps from a 22"bbl. This is NOT a +P load. 46.5gr is, however and is the traditional top end load for the Roberts with a 100gr bullet.
Going up to the 117-120gr bullets, I use 42.0gr as it too is most accurate and is still not a +P load. Going above this will get into the +P range. Out to 200yds, you can't beat the old Hornady 117gr RN. It also shoots flatter than the manuals will lead you to believe. I suspect that most of the b.c.'s are run using a 1/12" twist which doesn't stabilize the bullets as well as the 1/10" and gives better b.c.'s than I've been led to believe by the manuals.... such that I've actually over-shot more deer than I've under-shot with the the 'Bob...
Good luck with your .257Roberts. I had mine built in 1983 and have taken over 120 deer with it. It just works... with little recoil and amazing accuracy and is all the power you really need and essentially shoots as flat as a .270 w/130gr bullets....
What actually constitutes a +P load will depend on the chamber in your rifle. Most sporters have more generous throats on the chambers and this typically lowers pressures. I had a Ruger M77MkII that was maxxed out with the Hodgdon non-+P loads. Anything hotter led to cratered primers and burnished case heads. It too was more accurate with the "classic" non-+P loads.
It liked IMR3031 powder, of all things.... with a 100gr bullet. It "gagged" on either H380 or H414, whereas my custom M98 loves both, and is "ambivalent" on the IMR3031 loads.... But it does have the so-called 3" chamber.
Go figure....!
I use the traditional load of 45.0gr of IMR4350 with a 100gr bullet (Sierra's are most accurate, Hornady's best hunting bullet...) for about 2,950fps from a 22"bbl. This is NOT a +P load. 46.5gr is, however and is the traditional top end load for the Roberts with a 100gr bullet.
Going up to the 117-120gr bullets, I use 42.0gr as it too is most accurate and is still not a +P load. Going above this will get into the +P range. Out to 200yds, you can't beat the old Hornady 117gr RN. It also shoots flatter than the manuals will lead you to believe. I suspect that most of the b.c.'s are run using a 1/12" twist which doesn't stabilize the bullets as well as the 1/10" and gives better b.c.'s than I've been led to believe by the manuals.... such that I've actually over-shot more deer than I've under-shot with the the 'Bob...
Good luck with your .257Roberts. I had mine built in 1983 and have taken over 120 deer with it. It just works... with little recoil and amazing accuracy and is all the power you really need and essentially shoots as flat as a .270 w/130gr bullets....
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