257 AI Load data

dabrown56

Well-Known Member
Joined
Sep 20, 2018
Messages
69
Location
Hinckley, MN
Is there a GOOD source for 257 AI load data? Just got a 257 AI and I am looking for reliable tested data to start with. Will probably be using various 100 to 120 gr bullets.
Thanks
 
Start at max on 257 roberts data and work up from there.
^^^^^^^this^^^^^^^

In mine (now re-barreled to 338-06) I used a lot of 760, H4350 and H4831sc. Dabbled with RE19/22 and 780 (Supreme).
760 and H4350 ran so close in velocity and group size that I often had to check to see what powder I was actually using on the day, POI was very close together too.
I mainly used 100gr BT's, 100gr Speer HotCors and 110gr Accubonds.
I had a load with 115gr Partitions that I think I used less than 20 rounds of the 50 I made for deer, shot 17 animals and think 1 had 2 shots in it to bring it down, the first shot was a little far back from memory.
Of the powders I mentioned, 760 and H4350 were by far the standouts, same goes in my 338-06 actually.

Cheers.
 
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