More on the Barnes 275 XPB
The Barnes
.451 275 grain XPB paired to the MMP HPH12 sabot, pushed by Vihtavuori
N120 looks to be one of the most impressive combinations I've ever
found.
Here's today's
first 220 yard group:
Maximum
velocity deviation was only FIVE fps in a five shot string.
Erring on
the side of caution and safety, the predicted MAP remains below
30,000 PSI. Taking MMP's observation's as guidance, we try to stay
well below the accuracy velocity limit of the latest sabots under
ideal conditions, 2500 fps, and we also try to stay well below the
peak pressure accuracy limitation of today's best sabots: 35,000
PSI. This load meets these goals, and the 220 yard accuracy speaks
for itself. The pressure curve prediction uses 285 grains as a basis,
including ten grains for the sabot.
Only one of the Barnes
275 gr. XPB's was recovered; the rest are likely still en route
to Mongolia. The 100% weight retention of these bullets is clear
in this instance, despite a gash in one side likely from a subterranean
pebble. This is actually better than 100% weight retention-- I cleaned
away the earth from the bullet as best I could, but it seems something
close to a grain of it remains in the deep hollow point as shown.
This load retains
the requisite velocity of 1400 fps required for expansion (45 degree
petal opening) to 325 yards. MPBR with a 6" kill zone is 222
yards, retaining over 1675 fps and 1700 fpe at the range.
The 50 x .451 HPH-12
long, black MMP sabots are available from http://mmpsabots.com;
the 275 gr. Barnes XPB bullets, Barnes part # 45105, are brand new
but are available direct from http://www.barnesbullets.com
. You will likely need to call Barnes direct to get them, as they
are not catalogued as of this writing.
©
November, 2005 by Randy Wakeman
