THE HANDLOADING BENCH
308 Winchester Rides Again Part 2 By Laurie Holland
Anyway, onto the three freshly loaded batches in the ‘Palma’ brass, also starting at 46.3gn but now rising in 0.2gn steps to 46.7gn. Incidentally, I made sure the powder was from the same production lot as that loaded in the LRP control rounds.
46.3gn: 46.5gn:
46.7gn:
0.8” group 2,711 fps MV 33 fps ES 0.5” group 2,738 fps MV 28 fps ES
0.8” group 2,745 fps MV 61 fps ES
So, a charge weight around 47gn would have been needed to match the LRP/Fed210M 46.3gn load’s MV, two out of three spreads were better if not brilliant, but one batch of five gave a very poor result indeed.
Hmmm... taking the three sets of ammo, not a great result for the ‘Palma’ brass and SRP! But, was the mediocre to poor performance down to inherent inefficiency in these combinations, or was it temperature induced? Right, fast forward to 9th June 2011 on Diggle’s ‘A’ Range, nice and warm now in early summer. Er ... not exactly! 10°C and gusty crosswinds say my range notes. 10 degrees (50F) in June – that really says something about Diggle Ranges and the English summer of 2011! Anyway, the ‘Palma’ case, CCI-BR4 primer, 155gn Lapua Scenar and 45.5 to 46.5gn N140 (same production lot) combination was rerun as follows:
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