.300 Lapua Magnum

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.300 Lapua Magnum
Type	Rifle
Place of origin	Finland
Production history
Designer	Lapua
Designed	1989
No. built	small batch for C.I.P. registration
Specifications
Parent case	.338 Lapua Magnum
Case type	Rimless, bottleneck
Bullet diameter	7.82 mm (0.308 in)
Neck diameter	8.73 mm (0.344 in)
Shoulder diameter	13.82 mm (0.544 in)
Base diameter	14.91 mm (0.587 in)
Rim diameter	14.93 mm (0.588 in)
Rim thickness	1.52 mm (0.060 in)
Case length	69.73 mm (2.745 in)
Overall length	94.50 mm (3.720 in)
Case capacity	7.34 cm3 (113.3 gr H2O)
Rifling twist	240 mm (1-9.45")
Primer type	Large rifle magnum
Maximum pressure (C.I.P.)	440.00 MPa (63,817 psi)
Ballistic performance
Bullet mass/type Velocity Energy 10.0 g (154 gr) Lapua Scenar BTHP 1,096 m/s (3,600 ft/s) 6,027 J (4,445 ft⋅lbf) 11.0 g (170 gr) Lapua LockBase BTSP 1,040 m/s (3,400 ft/s) 5,986 J (4,415 ft⋅lbf) 12.0 g (185 gr) Lapua Scenar BTHP 1,010 m/s (3,300 ft/s) 6,135 J (4,525 ft⋅lbf) 13.0 g (201 gr) Sierra BTHP 980 m/s (3,200 ft/s) 6,216 J (4,585 ft⋅lbf) 14.0 g (216 gr) Sierra BTHP 950 m/s (3,100 ft/s) 6,406 J (4,725 ft⋅lbf)
Test barrel length: 690 mm (27.2 in) Source(s): AccuLoad [1]

The .300 Lapua Magnum (7.62×70mm) is a rimless, bottlenecked, centerfire cartridge developed for long-range rifles. The parent case of the .300 Lapua Magnum is the .338 Lapua Magnum necked down to a smaller caliber. The .338 cartridge case was selected to withstand high chamber pressures. Combining these high pressures with smaller, lighter bullets than its parent case, .300 Lapua Magnum loadings have high muzzle velocities.