Home Forums Hunting & Shooting Custom Rifles & Wildcats 300 H&H Necked To 7MM

Based on all that I read by you I suggest the H&H Super 30

HOLLAND & HOLLAND DESIGNED CALIBRES

275 H&H Magnum Belted Rimless


This cartridge was introduced in 1912 (the same year as the 375 H&H Magnum) and was the first of the �7mm� high performance rounds. (Germany followed post WWI with the 7 x 64 Brenneke)

The 275 H&H also marks the beginning of H&H�s regular use of the belted rimless cartridge case for all magazine rifle cartridge designs. The �belt� is a H&H design (and patent) introduced with the 400/375 cartridge of 1904.

Initially available with a variety of bullet weights, later production concentrated on the 160 grain bullet which was capable of carrying sufficient impact energy at the extended range of this high-performance cartridge. However we do still offer a 140 grain loading.

The 275 H&H led directly to the development of many similar cartridges, in particular the 7mm Remington Magnum which is close to a direct copy. The .270 Winchester cartridge has a similar performance.


Bullet weight 160 grains (10,4 gram)
Bullet diameter .287 ins (Note this is not a standard 7mm bullet)
Muzzle velocity 2850 ft./sec. (870 m/sec.)
Muzzle energy 2910 ft./lbs. (3950 Joules)
Service pressure 18.5 tons/sq.in. (3700 bar)
Cartridge case Belted rimless (same basic case as the .300 and .375)
Zeroed @ p.o.a. 200 yards (185 m) with a telescope sight
Trajectory @ 50 yds. + 0.5 in. (13mm)
Trajectory @ 100 yds. + 1.6 in. (41mm)
Trajectory @ 300 yds. - 7.3 in. (185mm)
Trajectory @ 400 yds. - 21.3 in. (540mm)


This was a very high performance round in 1912 but the ballistic table shows how difficult it is to avoid considerable bullet drop at ranges over 300 yards. Wind deflection also becomes a problem at these extended ranges.

Many attempts have (and still are) been made to improve on these ballistics but any improvements are at best marginal and raise the question of shooting at ranges where correct and humane bullet placement cannot be assured.