.280 Remington

Type

Rifle

Place of origin

USA

Production history

Designer

Remington

Designed

1957

Manufacturer

Remington

Produced

1957-Present

Variants

.280 Ackley Improved

Specifications

Parent case

.30-06

Bullet diameter

.284 in (7.2 mm)

Neck diameter

.315 in (8.0 mm)

Shoulder diameter

.441 in (11.2 mm)

Base diameter

.470 in (11.9 mm)

Rim diameter

.473 in (12.0 mm)

Case length

2.540 in (64.5 mm)

Overall length

3.330 in (84.6 mm)

Case capacity

67.9 gr H₂O (4.40 cm³)

Rifling twist

1 in 10 in (250 mm)

Primer type

Large rifle

Maximum pressure

60,000 psi (410 MPa)

Ballistic performance

Bullet mass/type	Velocity	Energy
120 gr (8 g) SP	3,112 ft/s (949 m/s)	2,581 ft·lbf (3,499 J)
140 gr (9 g) HP	2,839 ft/s (865 m/s)	2,506 ft·lbf (3,398 J)
154 gr (10 g) SP	2,825 ft/s (861 m/s)	2,730 ft·lbf (3,700 J)
168 gr (11 g) HPBT	2,723 ft/s (830 m/s)	2,767 ft·lbf (3,752 J)
175 gr (11 g) SP	2,681 ft/s (817 m/s)	2,794 ft·lbf (3,788 J)

Test barrel length: 24"
Source(s): Accurate Powder

The .280 Remington, also known as the 7mm Express Remington, was introduced in 1957 for the Remington model 740, 760, 721, and 725 rifles.

Having been released 32 years after the .270 Winchester, it had somewhat unspectacular sales; Remington renamed the cartridge in 1979, calling it the 7 mm Express in an attempt to increase sales. This resulted in people confusing it with the 7 mm Remington Magnum, and Remington changed the name back to .280 in 1981.

The .280 is based on the .30-06 necked down to accept 7 mm (.284in) bullets, with the neck moved forward .050in (1.27mm). The neck was deliberately moved forward to prevent chambering in a .270 Winchester rifle, as firing a .280 round in a .270 would cause the projectile to get stuck in the barrel over pressuring the rifle and leading to a barrel rupture.

Original loadings were 125, 150 and 165 grain bullet weights.

The .280 Remington is capable of generating slightly higher velocities with a given bullet weight than the .270 Winchester, and also able to use heavier bullets due to the larger .284" diameter. .284" bullets also have higher ballistic coefficients at the top of the weight spectrum than .277" bullets. The greater energy and higher ballistic coefficient of heavier .284" bullets give the .280 Remington a slight ballistic advantage over the .270 Winchester.

The .280 Remington is capable of developing energy nearly equal to the .30-06 Springfield, but with lighter bullets having a better ballistic coefficient. The .30-06 produces more energy than the .280 with bullets heavier than 180 grains, though .284" 175 grain bullets have a high sectional density of .310, compared to the 30-06 180 grain bullet with a moderate sectional density of .271. The .280 is suitable for hunting any game in North America with good shot placement.

SAAMI pressure limit for the .280 Remington is set at 60,000 PSI, 50,000 CUP.

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Wikipedia