Finding Good Game Loads Quickly
Date: Apr 28 2006
With the cost of today's premium bullets and the wear barrels take from high-pressure, high-volume, high velocity cartridges, it's a good idea to develop effective hunting loads with minimum testing. Here's one way:
Preselect your bullets based on need. For the deepest penetration go with Fail Safes, Lost River J36s, Barnes X-Bullets, Swift A-Frames and Trophy Bonded Bear Claws in just about that order. You might rank the Partition Golds in with the Bear Claws. Next in line are Partitions and most of the bonded bullets including the new polytipped models. Standard jacketed bullets would be most likely to maximize expansion at the cost of deeper penetration. To minimize the expansion and add a bit more driving mass behind it, use the heaviest bullets in this class, i.e. a 175-grain .284, 200-grain .308, 250-grain .338, etc. With the monolithic bullets in the deep penetrating category, you can step down in size and get penetration equal to the old, heavy slug standards. For instance, where you might want a 200-grain jacketed bullet for elk in a .300 Winchester Magnum, a 180- or even 165-grain Fail Safe or Barnes X-Bullet should give equal penetration. None of this is science, but it works most of the time.
If you're finicky about maximizing flat trajectory and minimizing wind drift, further narrow your choices based on ballistic coefficient ratings. The higher the BC, the farther a bullet of given caliber and weight will fly before dropping and the less it will drift in wind. Be aware that some BCs are inflated by manufacturers. Double check them on the range. I wouldn't sacrifice penetration potential for better BC on heavy or dangerous game. That's false economy. Terminal performance is the number one consideration. Everything else is just getting there.
With two or three bullets chosen, work up pressure loads with your top pick first. If it proves accurate enough, you won't even have to fool with the others. If you must leave your bench to test fire, build four or five rounds, increasing powder one grain at a time for 50-grain and larger capacity cases, a half grain at a time for smaller capacity cases. Start with your manual's starting load and go right up to its maximum. If you can shoot where you reload, just build one load at a time, stopping when you reach velocity/ pressure signs.
Now, from the bench on a good rest, fire each round at the same target just to get an idea how well they might group. Obviously different powder charges will mess up your groups, but some rifles print remarkably consistently with two or three grains powder differences.
Most critically, examine each fired case for pressure signs and correlate them with your chronograph. Loose chambers and/or bores generally require more powder to reach claimed velocities in manuals, tight chambers less. Feel for sticky bolts, look for cratered primers, flattened primers – all the usual high pressure signs. STOP when any load begins to exhibit high pressure signs. Do not fire the last one or two cartridges just because you have them. Pull the bullets back in your shop and reuse the case and powder, but don't jeopardize your equipment or self by touching off possibly dangerous loads.
Once you've determined a safe load, build three and shoot for accuracy. If it shows potential, play around with seating depth as you test three more. Better yet, measure bullet runout (alignment in the case.) This proves more critical to good accuracy than does seating depth in most rifles. You should be able to find a suitably accurate load with fewer than 20 rounds with this system.
If your first choice bullet isn't proving accurate, try number two. Remember, work up to maximum safe pressure by loading and firing just one round at a time, then shoot three for accuracy grouping.
One more thing. With high-velocity, big game calibers, don't work your tail off looking for that subquarter-inch group. It isn't necessary for hunting game larger than a coyote out to 600 yards. MOA is more than sufficient. Get too fussy and you'll shoot half the life out of your barrel before you ever use it on game.