Well reading all this .280 Ackley stuff got me sorta horned up...so beautiful warm day with NO WIND I dusted the ackley off and rounded up 3 powders, and 2 different 140's (Sierra & Nosler BT's)
My rifle is a 24" Nula with a chrome moly barrel.
first N165 and the campfire load of 63.5 gr and the 140 BT..Great accuracy about 3/8" but velocity of just 3000.
Increased 1 gr. and 3060
One more grain and 3100, but sl ejector mark on the nosler brass and the primers were dead flat..group opened up to 1 1/2"
A long way from 3300 and 7 mag territory!
R22 same bullet, went up to 64 gr. & slight ejector mark 3120. borderline too hot IMOP
R17 same bullet up to 59 gr. Too hot ejector mark -2" group and 3140 vel.
So the Ackley is a neat round certainly effective with 140's but IMOP is NOT a 7mm Mag. At least not with anything I am comfortable shooting out of it.
Lefty C
Lefty thanks for that information. Simply another example of the wide differences to be encountered between various barrels chambered for the same cartridges and something I've observed numerous times over the years ( not only with 7mm's, but with 270's, 30 caliber,and on up the ladder).More time spent with 30 caliber and under has shown more examples of it, but it exists elsewhere, too.
When I see us depending heavily on printed data and predicting absolute pressure results for a given cartridge, I blanche a bit....and especially when I see wild claims for smaller cases being the "equal" of larger cases, using pressure figures "assumed"(not known)I become even more skeptical and know immediately somethin ain't right.
I have no doubt I have run a 7 Rem Mag over SAAMI spec at times...and at other times well under.I still have not had anyone provide a reasonable explanation for the the fact that the Nosler manual shows,across the board,mor velocity from a 24" barreled 7 RM than a 26" barreled 280AI.
I think this stuff about loading one to 65,000 and the other to 61,000 and comparing them is an utterly silly conversation because the proponents don't have a clue what the pressures are in the respective barrels for each,other than reading about it.
They wouldn't get to first base in a courtroom doing things this way...which is why I find it so ridiculous.But courtrooms deal with "truth".... or try to....and reloading forums frequently deal in wishful thinking coupled with delusion and agendas.
