Choosing a Good Load
By Chuck Hawks
Selecting the right load for a metallic centerfire cartridge (rifle or pistol) requires some thought, some research, and some shooting. First comes the thought. What do you want to accomplish? Are you looking for a light recoiling practice and plinking load, a hunting load, a personal protection load, top accuracy, or do you have some other special purpose in mind? All of these will likely require different specific loads, so decide what it is that you want to accomplish from the outset.
Having decided that, then you need to decide how to accomplish your purpose. That is when you will pick a specific load or loads to test in your rifle. Let's (hypothetically) go through the process.
For example, let's say that I have a new .270 Winchester bolt action rifle with a high quality 3-9x40mm scope. I bought it for hunting all North American CXP2 class game (deer, goats, sheep, antelope, black bear and similar size game). All of these animals average less than 300 pounds live weight. And I want the potential to take advantage of the .270 Winchester's maximum point blank range (MPBR) of approximately 300 yards. That, in a nutshell, is the answer to what I want my load to do.
The next step is to decide how to get what I want from my new .270. To do that, I will have to find or develop an effective and reasonably accurate load that will accomplish my stated purpose.
In any hunting load, terminal effect and adequate energy on target are important requirements. This means that I will have to select a bullet that will give the rapid expansion and adequate penetration characteristics required for quick, humane kills on relatively light framed game. My reload will need to drive that bullet at close to maximum velocity if I wish to take advantage of the MPBR (+/- 3") of the .270 cartridge.
300 yards is a long way so, assuming for the moment that I have the skill as a marksman to hit the approximate 9" minimum heart/lung kill zone that the smallest of my intended quarries offer, I need a reload that will shoot into at least 9" at 300 yards, or 3 MOA. Realistically, since no one is a perfect shot, a minimum accuracy standard of 2 MOA (6" at 300 yards) would be more reasonable. So I will make 2 MOA or better my desired accuracy standard.
It doesn't take much research to discover that practically everyone who has much experience with the .270 agrees that the 130 grain bullet shoots flat and hits hard. With a SD of .242, it offers plenty of penetration for the type of game that I propose to hunt. 140 or 150 grain bullets would also suffice, but the 130 grain bullet shoots a little flatter and kicks a little less, and in any case is the bullet weight that made the .270's reputation. It will probably the best choice for my application. I will go with a 130 gain bullet.
Next I need to consider the specific performance characteristics the bullet needs. Because the .270 is a long range cartridge, and long range cartridges require a bullet with a reasonably high ballistic coefficient (BC), the bullet will have to be pointed in form.
Because I will be hunting thin-skinned game, the bullet should expand quickly enough to dump most of its energy inside the animal--there is no point in shooting holes in the countryside behind my buck. On the other hand, I don't want a bullet that completely flies to pieces on impact. I don't what a varmint (ground hog) or small predator (coyote) bullet. A soft point with a tapered jacket should do the trick.
There are a number of 130 grain bullets that would meet these specifications. Among the most popular of these are the Hornady SST and Interlock, Speer Hot-Cor, Nosler/CT Ballistic Tip and Ballistic Silvertip, Remington PSP Core-Lokt, and Sierra GameKing and Pro-Hunter. I have used all of these at various times, and most are available in factory ammunition as well as to reloaders. That is handy, as I always like to have a factory load as a possible alternative in case I run out of reloads some day.
I need to shoot my rifle to determine its bullet preferences and accumulate brass for reloading, so I will buy three different brands of factory loads with suitable bullets and test them for accuracy from a bench rest at a rifle range. For example, I might by a box of Remington Express loads with the 130 grain PSP Core-Lokt bullet, a box of Winchester Supreme ammo with the 130 grain Ballistic Silvertip bullet, and a box of Hornady Classic cartridges with the 130 grain Interlock SP bullet.
Let's say, hypothetically, that I achieve 3-shot groups from a bench rest that generally run between 1" and 2", and average 1.5" at 100 yards with the Hornady Classic ammo, and that it shoots the most consistent groups in my rifle. With a different rifle the results would probably be different, which is why you have to test more than one brand of ammunition. Anyway, 1.5" is well within my accuracy requirement, so the Hornady Custom .270/130 SP becomes my factory load of choice.
The Hornady Classic factory load has a MV of 3060 fps, and maximum reloads right out of the Hornady Handbook of Cartridge Reloading can equal or surpass that velocity with several different powders. The Hornady Interlock Spire Point bullet has a BC of .409, which is more than sufficient for my purposes. I will zero my rifle so that the groups center about 2.5" high at 100 yards with this load, which will maximize my point blank range.
Once I accumulate enough fired brass to make reloading practical, I can begin the last part of my load selection. My goal will be to essentially replicate the Hornady factory load.
The Sixth Edition of the Hornady Handbook lists four powders capable of driving the 130 grain SP bullet to a MV of 3100 fps. These are RL-19, RL-22, H4831, and VIHT N-165. The latter is hard to come by where I live, so that leaves three choices.
I have RL-22 and H4831 in stock, so I will initially load ten test rounds with each powder. That gives me three 3-shot groups plus an extra cartridge to re-shoot a flyer with each powder. I will start with Hornady brass and Winchester WLR primers, because those are the components the Hornady technicians who developed the loads used.
The next step is to decide how much of each powder to use. Remember, my target muzzle velocity is 3060 fps. I have been shooting full power factory loads in my strong, modern rifle with no problems and no signs of excessive pressure, so I am in good shape that way.
According to the Hornady Handbook, 59.6 grains of RL-22 powder gave a MV of 3000 fps, and 61.3 grains of the same powder gave a MV of 3100 fps. I will split the difference and try 60.4 grains of RL-22.
Also according to the Hornady Handbook, 60.1 grains of H4831 powder gave a MV of 3000 fps, and 62.0 grains of H4831 gave a MV of 3100 fps. I will again split the difference and try 61.0 grains of RL-22. These reloads may not be identical to the factory load velocity, but they will probably be close enough for my purposes.
There may not be much difference in the performance of the two powders, but for the sake of this article let's say that the H4831 load shot slightly more regular groups that averaged 1.25" at 100 yards and impacted pretty close to the same place as the Hornady factory loads. The velocity at 15 feet, according to my Chrony, averaged 3040 fps and the extreme spread was satisfyingly small.
Okay! Now I will load a full box of reloads to verify those initial findings, and if the results are similar, I have found my standard reload. I now have both a factory load and a reload tailored to my rifle and suitable for my purposes. Life is good.
Copyright 2005, 2014 by Chuck Hawks. All rights reserved.