Winchester technicians wanted their new creation to work through a standard length action to minimize rifle weight and avoid the long bolt throw of the long action .300 and .375 Holland & Holland Magnums. The difference amounts to a whole 1/4 inch. To maximize powder capacity, or maybe to have it look different than the .308 Norma Magnum, the shoulder was moved far forward which created a very short neck. The neck's length is less than .308, the bullet's diameter. This is a design flaw in the eyes of many handloaders. Several decades ago, cartridge design thinking dictated that a short neck wouldn't hold the bullet straight in alignment with the axis of the bore. Today, we know otherwise. It is a rare problematic rifle chambered for the .300 that won't hold 100 yard groups to inside of 1.5 minutes of angle, or 1 1/2 inches.

This short neck creates a more serious problem, though. Since a standard length action is used, the bullet must be seated deeply for the cartridges to fit in the magazine. Most of the popular .30 caliber bullets have a long taper, or give, and a short full diameter area. With the shank of the bullet below the case neck, it cannot be adequately gripped. Under recoil, the rounds in the magazine get battered about and the loosely held bullets fall deeper into the case. Not at all an optimum situation. Nosler Bullets has finally admitted that a possible problem exists and has designed a 180 gr. Protected Point Partition bullet specifically for the .300 Win. Mag. It only took 33 years. My own phone calls to Nosler and speaking with their reps at industry trade shows over the years only gained me responses of total bewilderment. Sierra Bullets ought to follow Nosler's lead. I long ago settled on the Hornady 180 gr. Spire Point. Its shorter give curve allows the case neck to get a firm grip. Winchester factory loaded ammunition uses a cannelured bullet and crimped case mouths to prevent bullet slippage. Case mouths cannot be crimped if the bullet lacks a cannelure, or crimp groove. Nosler doesn't offer cannelured .308 bullets in their Partition or Ballistic Tip lines. Sierra only places a cannelure on their Round Nose designs. For hunting purposes, where the same round in the magazine may be housed there over multiple firings, the Lee Factory Crimp die does yeoman work to hold the bullet from falling through the case neck. But, again, only if the bullet has a crimp groove. There has been much bashing and counter bashing in the firearms media between Lee and certain bullet makers over whether a non cannelured bullet should be subjected to the ministrations of the Factory Crimp Die. The jury is still out.

My test to determine adequate case neck tension is downright primitive. A folded shop rag is used as a cushion and a "dummy" round is pushed firmly into the edge of my loading bench. With all the Sierra offerings and the old style, standard Nosler missiles only minimal hand pressure pushed the bullets completely through the case neck.

Another slippage prevention method suggested from time to time is to use a slow burning, bulky powder that provides 100% load density, or a totally full case. Hodgdon H1000 , IMR 7828 and Accurate Arms 8700 are candidates if you're inclined to experiment with this solution. A tighter resizing die using a smaller interior neck diameter with a smaller diameter expander ball doesn't work. I've already blown a few bucks trying this route. The bullet, upon seating, only stretches open the neck and we're back to square one.

Of course, if the magazine is not used and rounds are single loaded into the chamber the restrictive overall cartridge length of 3.340" can be ignored. Anyway, best. accuracy with any .30 caliber cartridge is achieved by seating the bullet out to where the full diameter shank is just short of touching the bore's lands.

Mike Harris, Nosler's Director of Customer Satisfaction, came up with the best fix for this problem. But, its only doable with a Winchester Model 70 rifle. The Model 70 was designed in 1936 as a long action. For use with shorter cartridges, like the .30-06 and its cousins, the rear of the box magazine was blocked and a different bolt stop was used since the longer bolt travel wasn't necessary. Simply replace the .300 Win. Magnum box magazine and cartridge follower with the longer .300 Weatherby version, alter the bolt stop to allow for another 1/4" travel, and voila!--the bullet can now be seated out more than enough to position the full diameter shank well within the stubby case neck. This ingenious and inexpensive modification would allow the use of bullets with the longest give curve without any increase in rifle weight.

The .300 Win. Magnum, among non-proprietary cartridges, provides all that could be desired in a long range hunting and target round. A 180 gr. Spire point type bullet started at 3000 feet per second from the .300 provides a trajectory a full 25% flatter than the same bullet started at 2700 fps from a .30-06 at a distance of 300 yards. As for inherent cartridge accuracy, I've yet to work with any .30-06 rifle that will print groups as small as the .300 will.

Plan on seeing this great round on the firearms scene for a long time to come.