With new, high B.C. .277” bullets now weighing 160 to 175 grains, the old 270 would seem to be in need of faster rifling twists. The traditional 1:10 twist is too slow to stabilize those long projectiles. But such long bullets might not be necessary for effective terminal performance at 500 yards and less, easily the distances at which the vast majority of game is taken.
A 150-grain AccuBond Long Range, B.C. .591, flung 2,900 fps from a 24-inch barrel and zeroed 3 inches high at 100 yards hits no higher than 3.5 inches at its maximum ordinate (150 yards) and doesn’t drop 3.5 inches below point-of-aim until 335 yards. At 400 yards it’s just 14 inches low and at 500 yards 31 inches low. Remaining energy at 500 yards is 1,559 foot-pounds, more than the 1,500 f-p often cited as benchmark terminal energy for taking elk. Deflection from a 10 mph right angle wind at 500 yards is a mere 14.5 inches. Does the 270 Winchester need heavier bullets? Not according to these calculations. At the more reasonable long range hunting distance of 300 yards that 150-grain AccuBond Long Range will be hauling 1,988 foot-pounds of energy.
Ammunition and Bullets Aplenty
Controlled expansion bullet construction combined with today’s superb form factors elevate the old 270’s performance to new levels. As indicated by the AccuBond trajectory numbers above, high ballistic coefficient aids significantly. If we hunters even knew what B.C. was back in the mid-20th century, we certainly didn’t dote on it. Now we do, understanding how more aerodynamic efficiency not only extends range and minimizes wind deflection, but husbands energy. Combine higher striking energy with deeper penetrating bullets that expand reliably while retaining 80% or more of their mass and you make the 270 Winchester pure poison on caribou, elk, moose, bears, and all Africa plains game. And you can find such bullets in most factory ammunition brands. Look for Barnes TTSX and LRX, Swift Scirocco, Nosler AccuBond Long Range, Federal Terminal Ascent to name a few. Handloaders can seat Cutting Edge Laser Tipped Hollow Points, Lehigh Defense ELR, Hammer Hunter and the like. At 2,900 fps launch speed, a 150-grain .277 is packing 2,800 f-p of energy, and those high B.C. bullets preserve it beautifully.
Less robust bullets designed for more dramatic upset have their place too, and sleek boat tails behind long ogives nudge B.C.s into nose bleed territory. Hornady’s ELD-X, Berger’s VLD Hunting, Sierra GameKing, etc. help the 270 shoot flatter than ever with good terminal performance on pronghorns, mule deer, whitetails, sheep, and similar game.
Can 270 Winchester Hang with 6.5 Creedmoor?
Source
Better Hunting Cartridge Than 6.5 Creedmoor and 30-06? — Ron Spomer Outdoors is written by Ron Spomer for www.ronspomeroutdoors.com