The 7-30 Waters
By Chuck Hawks
Gun writer Ken Waters designed this cartridge in 1977 for the lever action Model 94 Winchester rifle. It is based on the .30-30 Winchester case necked down to accept 7mm (.284") bullets. In 1984 Winchester introduced the cartridge in the Model 94 rifle with a 24" barrel and the Model 94 carbine with a 20" barrel. The 7-30 Waters offers flatter trajectory than its .30-30 parent, plus the bonus of lighter recoil.
In 1986 Thompson/Center picked the 7-30 for its Contender carbine and also its Contender single shot pistol. It has proven to be an excellent cartridge for the handgun hunter, the factory load exceeding 2400 fps from a 14" Contender barrel. Unfortunately, Marlin has not seen fit to chamber their Model 336 for the 7-30 (yet), which would seem to be a natural combination.
The only factory load for the 7-30 comes from Federal, a 120 grain Sierra Pro Hunter flat point, boat tail bullet at a muzzle velocity of 2700 fps with 1940 ft. lbs. of muzzle energy from a 24" barrel. At 200 yards the velocity is 1930 fps and the energy is 990 ft. lbs. A flat point bullet is required due to the Model 94's tubular magazine. The SAAMI mean maximum pressure for the 7-30 is 40,000 cup.
The 7-30 kicks only slightly more than a 6mm rifle, and somewhat less than a .30-30. In a 7 pound rifle the 120 grain factory load kicks the shooter with 11.23 ft. lbs. of recoil energy, according to my Rifle Recoil Table.
Ballistically, the 7-30's advantage over the .30-30 is at ranges in excess of 200 yards. According to Federal figures a scoped 7-30 rifle zeroed at 200 yards will hit 2.4" high at 100 yards and 9.8 inches low at 300 yards. This makes it about a 250 yard deer rifle. The point blank range could be extended to at least 275 yards by zeroing a 7-30 rifle to hit 3" high at 100 yards, but the cartridge is limited more by its remaining energy than by its trajectory. Remember that these figures are for a 24" barrel, and a 20" carbine barrel will give somewhat less velocity and more drop.
The handloader with a 7-30 lever action rifle can choose between 120 grain and 139 grain flat point bullets from Nosler and Hornady. If he or she owns a single shot rifle or pistol any 7mm bullet can be used, but clearly the lighter bullets are more suitable given the limited power capacity of the 7-30 case. The cartridge is reported to be easy to reload for, and is not picky about powder. The Hodgdon Data Manual, 26th Edition suggests starting with H4895 or H335.
According to Hodgdon figures 31.0 grains of H4895 can drive the 120 grain Nosler bullet to 2537 fps, and 34.0 grains of H4895 will take the same bullet to a MV of 2733 fps. The 139 grain Hornady bullet can be driven to a MV of 2310 fps by 29.0 grains of H4895, or 2458 fps by 31.0 grains of the same powder. These figures were taken in a 24" barrel. They recommend the 120 grain bullet for the smaller species of deer and the 139 grain bullet for mule deer and black bear.
Copyright 2002 by Chuck Hawks. All rights reserved.