Still Shooting
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My Ruger M77 .257 Roberts needs reloads, and my brass has all been shot multiple times - I've had 2 case neck splits, in spite of re-annealing at 3 and 4 reloads. I recently tried necking down a few once-fired 7x57 Mauser rounds, knowing that that is how the .257 bob came into being. I checked SAMMI case specs first, and then went ahead with these cases. After resizing, I measured the case length (.005" - .008" longer than trim-to length) and the neck wall thickness (uniform at .015").
I trimmed, reloaded, and they seem to function OK. My load is IMR 4350 - 40.0 gr./CCI 200 LRP/ Nosler CT Bal. Tip - 95gr. I have read (elsewhere on this forum) that the 7x57 has slightly less case capacity than a .257+P, and I am wondering if I need to adjust the load downward. My current load shows no signs of high pressure, although it's not a mild one. It also delivers about 1 moa with .257+P brass.
Since new Roberts brass is nonexistent out there right now, I bought 50rd. of Winchester 7x57 Mauser to resize and load. Is there anything more I need to know about the process of resizing and using this brass in my Ruger M77 Roberts?
I trimmed, reloaded, and they seem to function OK. My load is IMR 4350 - 40.0 gr./CCI 200 LRP/ Nosler CT Bal. Tip - 95gr. I have read (elsewhere on this forum) that the 7x57 has slightly less case capacity than a .257+P, and I am wondering if I need to adjust the load downward. My current load shows no signs of high pressure, although it's not a mild one. It also delivers about 1 moa with .257+P brass.
Since new Roberts brass is nonexistent out there right now, I bought 50rd. of Winchester 7x57 Mauser to resize and load. Is there anything more I need to know about the process of resizing and using this brass in my Ruger M77 Roberts?