6.5-300 Wby Mag
123 AH
26" 1:8" T Wby Vanguard
New Wby brass. Neck expanded and 1/8 T Lee FCD
Federal 215
COAL: 3.6"
Reloder 17
68.0: 3298 fps
68.5: 3354 fps
69.0: 3367 fps
69.5: 3457 fps (light ejector swipe)
70.0: 3460 fps (light ejector swipe)
70.5: 3420 fps (light ejector swipe. Consider to be max for this rifle)
71.0: 3480 fps (light ejector swipe and stiff bolt)
Reloder 22
75.0: 3380 fps
75.5: 3357 fps
76.0: 3385 fps
76.5: 3412 fps (light ejector swipe)
77.0: 3410 fps (light ejector swipe)
77.5: 3474 fps (light ejector swipe. Consider to be max for this rifle)
78.0: 3507 fps (light ejector swipe and stiff bolt)
IMR 7828 SSC
75.0: 3262 fps
75.5: 3287 fps
76.0: 3283 fps
76.5: 3417 fps
77.0: 3330 fps
77.5: 3357 fps
78.0: 3385 fps
No signs of excess pressure, but velocity was not linear.
Gun may not like the bullets.
And you said other guns didn't like them.
I was getting those speeds from 127LRX.
H4350
75.0: 3417 fps
75.5: 3462 fps
76.0: 3421 fps (light primer swipe. Consider to be max for this rifle.)
76.5: 3467 fps (heavy primer swipe and very stiff bolt). Stopped here.
Overall, some increase in speed over N560, but still not where I want to be especially considering the pressure signs. Given that this is the 3rd rifle in which the 123AH has not met velocity expectations, I see little sense in wasting additional powder on this endeavor. But, since I have 50 left, I'm open to suggestions.