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O/T Norma/Weatherby Brass-Primer Pocket?

Discussion in 'Uncategorized Threads' started by Sgt. Mike, Dec 18, 2007.

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  1. Sgt. Mike

    Sgt. Mike TS Member

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    I've been reloading some Norma brass for the .257 Weatherby Magnum. When the casins approach the maximum load for MRP powder, the primer pockets expand. The casings are still in near perfect condition. Have others had this problem? If so any solution? Any oversized primers for rifle? Has anyone tried anything to harden the base of the casing? Thanks in advance, Michael
     
  2. Dutchboy

    Dutchboy TS Member

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    When you measure the bases of Norma brass, you will find that they tend to be several thousands smaller than domestic brass. Hardening the base (if it could be done) would not really help with the expansion problem: the brass dimensions are the real cause of the issue, combined with hot loads.

    Though some brands of primers tend to be ever so slightly larger than others, there are no "oversized" primers I am aware of.

    Quit redlining your reloads, and the problem will go away. HTH, Dutch.
     
  3. Sgt. Mike

    Sgt. Mike TS Member

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    I realize I can reduce the powder. Some of the casings I got years ago take the max load just fine and no primer problems. If I continue to reduce the load I have a 25/06. Could the brass casings we are purchasing be softer brass? Sgt. Mike
     
  4. Shooting Coach

    Shooting Coach Banned User Banned

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    There are four problems you are having.

    First, using loading data developed years ago with different lots of powder, brass, primers and bullets is asking for trouble. Are you using the same rifle? If you have throat erosion, pressures will INCREASE in these barrel burners.

    Second, Roy Weatherby was a gunsmith, very familiar with cartridge design. A case with minimum taper will likely develop loose primer pockets or even blow a primer without having difficult extraction. The domestic .458 will do the same thing. You can load it hot enough to blow primers every shot and not have difficult extraction.

    Third,if your rifle is a factory 257 WBY, it is freebored, to lower pressures somewhat. If you are seating the bullet close to the throat, you will increase pressure. If your gun is a custom, it may not have any freebore, which will increase pressure of any load.

    Fourth, if your brass is on the thick or soft side (which Norma sometimes is), your bullets are on the hard side (like Barnes "X" bullets), or primers are on the upper end of the spectrum (an especially HOT batch of the FED 215), you may be developing excessive pressure. For that reason, one should ALWAYS start with a slightly reduced load and work up to max with the components you are using in your rifle.

    If you fireform domestic brass, the max length of the 264 Win Mag is 2.500". The max length of the 257 is 2.549". The 264 will stretch a little when squeezed down to 25, but be aware of this. Also, be aware that the flash hole of domestic brass is typically larger than Norma brass. This in itself will increase pressures.

    Don't start at maximum listed loads. The max listed load in the manual is maximum FOR THAT RIFLE WITH THE COMPONENTS THEY USED. You DID use a manual, didn't you?

    Overbored barrel burners are fun, but they are only worth their weight for game shots at extended range. They are expensive to buy, expensive to shoot, a pain to clean, and the barrels don't last long if you shoot them much. These are NOT plinkers.
     
  5. Sgt. Mike

    Sgt. Mike TS Member

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    Shooting Coach,

    Thank you for the information. The gun is the same but loading data has changed. The gun probably has 50 rounds through it. It's a factory Mark V with a muzzle brake and a Canjar Trigger. It shoots under 1/2" at 100 yards.

    When you mention the flash hole are you saying to open it up to the same dimensions as U.S. made brass?

    The gun is strictly hunting and then for only part of the season. I use all sorts of loading data. I have Hornady, Nosler, Speer, Sierra, Norma and a combination book from Lyman. Also I have Handloader Magazine from their first magazine to current. With that I contacted Norma directly for their load data which they provided.

    Today I'm going to start low and work up to a satisfactory load that doesn't blow primers. Then when I have more work to do I'll chronograph the load and run it through the computer. Let me know what you would do with the flash hole?

    Also some data calls for a magnum primer others call for a standard primer. Your thoughts? Norma says magnum, most of the other books say standard.

    Thank you to everyone and have a Merry Christmas, Sgt. Mike
     
  6. coyote_198

    coyote_198 TS Member

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    Sgt. Mike I own (8) Weatherby now have had about (18) shot over (50) others I've never seen a Weatherby that would shoot a 1/2" group. Now that I've pissed some people off, use remington brass.
     
  7. halfmile

    halfmile Well-Known Member

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    Shooting coach has good info.

    Of particular interest is the statement on freebore. Roy found out He could get the velocit he wanted by allowing plenty of bullet movement before engaging the rifling.

    IMR had a disclaimer on this in their loading pamphlet. The later pamphlets do not show the .257.

    I would be happy to share this Load data if you email me.

    My 257 works fine. I use Federal 215 Magnum primers, and 7828 powder. I would not consider anything else. These are very accurate loads for my rifle.

    HM
     
  8. Sgt. Mike

    Sgt. Mike TS Member

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    Halfmile,

    You have e-mail and thanks.

    Coyote_198,

    Remington does not make .257 Weatherby Brass. They do make .300 Weatherby Brass but that can not be necked down. Thank you to everyone. Sgt. Mike
     
  9. Shooting Coach

    Shooting Coach Banned User Banned

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    I would not enlarge the Norma flash holes. They are drilled, while our domestic brass is punched.

    As far as primers, the Federal 215 was designed for the WBY cartridges. As a hunting round, it will likely be fired, at least in our country, in inclement, if not bitterly cold weather. A hangfire is the last thing you want on that long shot, on the last day of the season, after an exhausting stalk!

    I would stick with the original brass. Use new brass for your hunting ammo and the maximum load. It seems to me a well designed 120 gr boat tail bullet is the way to go with the WBY. It may be slower initially, but past 300 yards or so its superior ballistic coefficient will allow it to retain speed better at the extended ranges the 257 was made for.

    If you cannot get over 3200 fps with this bullet and MRP, look at Accurate Arms 8700, H1000, and whatever you do, DON'T overlook IMR 7828.
     
  10. Sgt. Mike

    Sgt. Mike TS Member

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    To Shooting Coach and everyone else who helped with this thread. We thank you for the information. I've started working up loads from the beginning and want to give some IMR 7828 a try along with the 120 grain bullet. Merry Christmas and a very Happy New Year to everyone. Michael and Jane
     
  11. larryjk

    larryjk Member

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    If you are not a true believer in a clean barrel, a .257 Weatherby can build high pressure from "brass" deposites in front of the throat. Keep that throat clear of any copper. Lower pressure and better accuracy.
     
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