Load Development (Part 2)

This is the second post in a multi-part series on Load Development. Here is Part 2 Setting Standards.

Setting Standards

If you are asking why set a standard? Well, if you don't set a standard, or a goal, then there isn't much point in going through this whole process of developing a load. No matter what your goal, you should set a standard, and make sure you conform to it. This will make reloading easier and more fun, it will also make shooting more fun and hopefully reduce stress at matches when you could be worried about how your ammo is going to perform.

So what goes into a standard? Well, the first thing you should do is decide what you want the ammunition to do. At the same time you should remember that every decision is a trade off, and the number of decisions you get to make every time you make one shrinks exponentially. If your goal is creating a round that uses the cheapest bullet, cheapest powder, has the lowest charge volume, gives phenomenal accuracy, insanely high muzzle velocity, and has zero recoil that's great. Send me a message when you've achieved this, I've been trying for nearly 20 years and have never even come close.

The first thing you should decide is what the basic requirements are for your cartridge. Let me illustrate this with an example, .223 Remington. A good goal: "I want it to cycle my AR-15 without issue" Sounds easy right? Well this immediately limits you to medium burning powders such as H332, Varget, AA2230, TAC, and eschews fast burning powders like IMR4198, IMR4227 and the like. The next goal should be either your accuracy or muzzle velocity. Most frequently the most accurate loads are not the ones pushing maximum velocity, in fact quite far from it. So this is a fork in the road. Since you clearly want to fire this cartridge out of a semi-automatic rifle, you are bound by a certain max over-all length of the cartridge, in this case 2.260" but it works best when loaded to 2.250" or less.

So lets pick an accuracy load, in my opinion, life is too short to miss, and missing is much more affordable when shooting a .22LR than a high powered rifle.
I also want to shoot at medium to long ranges, so I want a bullet that's heavier and more streamlined than the short FMJ-BT bullets that are so cheap, the Sierra 69gr Match-King is a great bullet, but the 60gr SMK, and 55gr SMKs are also great choices for certain applications, like if I was shooting with a carbine length barrel instead of a rifle length barrel.

So lets browse through the available loads, here are a few from data.hodgdon.com:

69 GR. CFE 223 2.235" 23.5 2788 25.8 3029 54,600 PSI
69 GR. Varget 2.235" 24.0 2784 26.0C 3010 50,200 CUP
69 GR. IMR 4320 2.235" 23.0 2673 24.8 2873 53,100 PSI
69 GR. IMR 4064 2.235" 22.5 2690 24.0C 2872 50,900 PSI

So it seems I can expect a muzzle velocity out of my 20" gun up to around 3000FPS. Now like I said earlier, the fastest load will not always be the most accurate, so 3000FPS is going to be the upper limit of how fast I'm expecting this bullet to go. The next consideration is the minimum velocity I'm willing to tolerate. After doing a little bit of checking, the 69gr SMK has a BC that averages about .305, so using an online ballistic calculator, if I load to a minimum velocity of around 2700FPS, I can expect the bullet to be transonic as the bullet approaches 800 yards, however if I can keep the muzzle velocity to around 2850FPS the bullet will still be marginally supersonic at 800 yards, giving this round an accurate range out to this distance. So now I have an upper and lower bound.

In a home situation, now would be a good time to pick out a powder, usually the starting point for this, is "what do I have?" otherwise it is now time to make a shopping run and go buy some powders. If you have experience and certain favorites for this, by all means use that. One of my personal favorite powders is Varget, which conveniently is shown above. However, for completeness, I like to choose at least one other powder I think may work well, this may be because a different powder is more available, it meters better, or any number of other reasons. A common powder for .223 Rem is H335, I have a lot of it around, so I will add that to the spec.

So now I have created a rough specification for my cartridge:

Caliber: .223 Remington
Powder: Varget, H335
Charge Wt. 24-26, 22-24
OAL: 2.235-2.250"
Velocity: 2850-3000FPS

Now it's time to load some test cartridges, which will be the next installment.