257 WBY

RL338

Handloader
Mar 23, 2017
908
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Part 2 of my afternoon. I also took my 257 WBY along today and worked with Hornady 120gr HP , Alliant RL-33 Federal 210 , Winchester Brass (formed from 7mm Rem Mag) seated at 3.300” I worked from 79.8gr to 81.0gr as follows
79.8 =3342 fps
80.0 = 3306
80.2 = 3342
80.4 = 3355
80.6 = 3364
80.8 = 3372
81.0 = 3372
I also loaded 3@78.5 , 79.5 , 80.4 for groups 5114831B-CB2D-4B61-B257-C1347EE4F524.jpeg B63193DD-399D-43AB-AEEA-EFBAB3CE70D8.jpeg DCD598F4-EE8D-4842-9F26-53563B0F2BA7.jpeg
I think I’ll work around 80.9gr and see what comes of it.
81gr would be high as I go , starting to get cratering , a couple of weeks ago I tested up to 81.5gr by 1/2gr at a time and stop speed was ridiculous for a 24” barrel.
Again this is not WEATHERBY 257 Brass so anyone thinking of trying RL-33 needs to start WAY lower
 

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