There is a long-standing tradition in shooting magazines of publishing “pet” loads for different cartridges. Leaving aside the harsh ballistic fact that what works beautifully in one rifle may be mediocre in another, there are simply too many variables at work. At best, a pet load will give you a starting point.
About 60 years ago, before H4831 came on the scene, Jack O’Connor spent months loading and testing cartridges for the .270 Winchester. Reportedly, he fired 10,000 rounds altogether, which is a lot of shooting. The load he arrived at was 49.5 grains of IMR-4064 with a 130-grain bullet. It was, he wrote, wonderfully accurate in every rifle he tried.
After H4831 arrived, delivering higher velocities in the .270, O’Connor made it his standard powder. Whether he ever used the 4064 load again, I don’t know.
Still, I was intrigued. Every .270 rifle? I had to try it. The first step was to check that load against maximums listed in load manuals. Not one current manual lists it, or even anything close. The heaviest I could find anywhere was 47.5 grains. Even going back to Lyman Manual No. 45, published in 1970 — one of what Dean Grennell characterized as the “intrepid” manuals because of their generally hotter loads — the heaviest listed was 49.0 grains.
Being the fearful sort, I worked up, chronographing as I went along, and reached 49.5 grains with absolutely no hint of excess pressures. Nor, however, did I reach 3,000 feet per second, which O’Connor reportedly did. My explanation is that there are wide variations in case capacity of the .270 from one maker to another. O’Connor used Winchester brass — and that was around 1950, remember — while I was using more roomy Nosler brass of recent make.
Experimental handloaders will immediately spot the problem here. If O’Connor was getting higher pressures and velocities, then it was, to all intents, a different load. Since I am not duplicating his load, I should not expect to duplicate his results.
Still, having come this far, I lined up five .270s to try it out, shooting a ten-shot group from each. The rifles included a Blaser R8, Sauer 404, Mauser M18, Winchester Model 70 Featherweight (new) and a custom rifle on a Mauser action by Al Biesen — a gilt-edged performer if ever there was one. Again, there was not a single pressure signal with any cartridge in any rifle. All had barrels in the 21 to 22-inch range, so some velocity loss was to be expected anyway, and only the Biesen topped 3,000 fps (3,051).
Ten-shot groups tell you a lot more about a rifle and load than any number of three-shot groups. As a generalization, all shot very well with that load. The Mauser M18 was the best (1.28-inch) while the Biesen custom was the poorest (2.3 inches). Both the Sauer (second-best) and the Model 70 were hurt by one flyer, otherwise, the Sauer delivered a nine-shot group of 1.18-inch. But that’s not the point, is it? It’s a ten-shot group.
By the same token, the Mauser M18’s first three shots were in a group less than a half-inch, and the next three were also less than a half-inch. Unfortunately, there was a half-inch gap between the two. Had I used the now-accepted standard of averaging three, three-shot groups, it would have had a spectacular score. Again, this is why ten shots tell you more than groups of three.
Two other interesting points: The M18 is the least expensive rifle of the bunch, but had the best group. The Biesen delivered the highest velocity, yet had the poorest group. Regardless, I would cheerfully go hunting with any of those rifles tomorrow, using that load.–Terry Wieland