Educational Zone #153 – How to Develop Accurate Target Loads for a Rifle

I recently posted about a new rifle I had bought and a friend from AR15.com, Bubbatheredneck said:

“May I suggest you keep a diary of how you do your load workup for this rifle, why you picked which components, accuracy results for each load, what you changed and why you changed it as you finalize your end all, be all target load for this rifle.

I think many folks would like to see that data presented in your own way.”

I thought that was a capital idea, so here goes.

First, a qualifier: This is how I work-up accurate loads. Other folks may do it differently. You can go to the excellent Reloading Forum on AR15.com to learn more.

Loading for a rifle is different than loading for a pistol. Rifle brass “grows” in length as you shoot it and will need to be trimmed if it gets too long. Very small changes will show up in many ways on the target. Small things matter with rifle ammo.

The main thing you go for is Consistency. Any variable in the ammo will result in the bullets spreading out on the target. The more consistent and “exactly the same” the ammo is, the better the accuracy will usually be.

I start out with some once-fired brass. I am loading for my Savage bolt action which is chambered in .223. I had some IMI (Israeli Military Industries) ammo that I had shot in one of my AR-15 rifles. I had 60 rounds to start with. The ammo is labeled as .223 ammo.

Just as an aside for those that might not know… .223 ammo and 5.56 (the military designation) are not exactly the same. The cases are identical in proportion, but the 5.56 ammo is loaded to higher pressures. If you try to shoot 5.56 ammo in a .223 chamber, the higher pressures can lead to excessive pressure and even pierced primers. But once it is fired, you can reload either .223 or 5.56 cases to .223 pressures.

I first fully resize the brass. I do this for two reasons. First, I use a Giraud trimmer and that requires a fully resized case. And secondly, I am going to be using this brass in a different rifle that it was originally shot in. That means we want to be sure that it chambers in the new (and possible tighter) chamber.

Since it is military brass, the primers are crimped in, so I use an RCBS tool to remove the crimp, which allows smooth insertion of the new primers.

For the most accurate loads, I must first shoot the brass in the bolt rifle, and then I will “partially neck size” the brass. This means that I will back off the sizing die and only size the neck of the case about ½ to 2/3 down the neck.

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Here’s a fully resized brass on the left and a partially neck sized round on the right.

Here’s a fully resized brass on the left and a partially neck sized round on the right.

The reason for this is that it allows the brass to be loaded many times, as the brass isn’t “worked” as hard.

But mainly, it is because a neck-sized piece of brass will fit “snugly” in the rifle chamber.

This will perfectly align the bullet with the axis of the bore and lead to better accuracy.

It also means the loaded cartridges will be slightly “tight” in the chamber, but the nice, big bolt on my Savage allows easy bolt closing.

If this is not clear to you, look at the illustrations in the front of many reloading manuals and they will help you understand the advantages of neck-sized-only brass.

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After resizing, I then used a Lyman Flash Hole Uniforming Tool on the brass.

The flash holes in brass are “punched” through the brass as it is manufactured.

This can result in a piece of brass being left inside the case at the edge of the flash hole.

This tool removes this excess brass and uniforms the flash holes.

It is a minor thing, but small things and consistency are what we are looking for.

Here's the tool.

Here’s the tool.

I just insert the tool through the neck of the brass, give it a twist, and it will shave off any excess brass and give uniform flash holes.

This once-fired brass is a little dirty, and, as we all know, pretty brass shoots better. So, I ran it through my media vibrator and polished it up.

Just as an aside, I was kidding about pretty brass shooting better. Shiny brass doesn’t shoot better or more accurately.

But I like shiny. So, I shine it up.

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I then run each piece of brass through my Giraud trimmer to make it all the exact same length and to true-up the neck.

If I neck size only, this step will only be needed after many reloadings of the brass.

I can measure the brass to know when it is needed again.

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I then seat a fresh primer in each case.

Brand of primer is not too critical, as long as you use high quality primers and use the same primer for all loads.

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I then pick a powder for the load. There are many powders that can be used and I usually use one that I have had good luck with in previous loads. Today I will be trying some Accurate Arms AA-2460 and some Hodgdon H335. I’ve had good results with both of these before. If they don’t work out, I can try others.

Even though I have been reloading ammo for many years, I ALWAYS refer to a couple of loading manuals for the proper load. I usually look at the Maximum load and back off to a more moderate load and go from there. If it shoots reasonably well, I try more or less powder, always staying within Maximum loads for that cartridge.

One of the things I seek is a powder load that will “fill the case” with powder to the bottom of the bullet. Even a slightly compressed load can often be the most accurate. But this is all regulated by the Maximum loads listed in the manuals.

I watch the brass, especially the primer for signs of high pressure. But if you stay below the Max load, you will usually be just fine.

We then come to the most important part of any load, the bullet.

No matter what else you do, if you do not use good bullets, you will never get good results.

Today I will be trying an old favorite, the Sierra 52 grain BTHP, #1410M.

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I will also be trying a few heavy bullets sent to me by my friend Torf. These are 75 grain Hornady A-MAX bullets.

The box is marked “Twist rate 1-9”. My rifle has a 1 in 9 twist, so I expect it will stabilize these long and heavy bullets just fine.

We will also see if this rifle “likes” them.

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In a magazine-fed rifle, such as the AR-15, cartridge length is critical, as the cartridges must fit and feed from the magazine.

On a bench rest rifle such as this one, I can load them longer and just single feed them. But even then, you must be careful not to let the bullet sit out so long that it contacts the rifling in the barrel, as this can lead to greatly increased pressures. Again, read and study a reloading manual to completely understand this issue.

I carefully label and package the ammo, so that I will be able to accurately keep track of what I am shooting and record how well it does. There is nothing worse than finding a great load and then realizing that you forgot what it was.

Then it is time to go to the range…, and the fun starts. I shoot groups of at least 5 shots and note the size of the group. If I see an accurate load, I will try it again, and also try a load with slightly more of less powder (all within the manual range) to see if I can improve the load.

After a while, I can usually find a “sweet spot” for that bullet and powder combination and that can become my “main load” for that rifle. Most of my bench guns have such a load.

Of course, for many of us, once you find the “best load”, the fun is mostly over. I enjoy the process to seeking the best load for any rifle. It is a great hobby.

I was visiting my buddy Ted up in Temple, TX, and we went to the range and shot some groups.

Here’s Ted on the rifle.

Here’s Ted on the rifle.

Sadly, it was 40 degrees and the wind was blowing about 30 mph, but we managed to get some good groups anyway.

The rifle “likes” the 75 grain A-MAX bullets and stabilized them just fine.

Note that the holes are round, and that indicates that the bullets were not yawing at all.

That one flier was my fault, not the rifle or the bullets.

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The 52 grain Sierras shot great.

Here’s a few 5 shot groups.

Here’s a few 5 shot groups.

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Here’s a great group that Ted shot, but he had a called flier that messed up the group.

Not all groups were dime-sized, but they were all sub-MOA.

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And here's some of my Sierra 52 grain BTHP loads.

And here’s some of my Sierra 52 grain BTHP loads.

Conclusions:

I will continue to fine-tune the loads. I have a lot of hope for this fine rifle.

Update:

I went out today and shot some nice groups.

I had some bullets a vendor had given me at the SHOT Show.

They were not advertised as “Target” bullets, but as “good” bullets.

They were 55 grain FMJs.

I thought I would load up a few and see how they shot.

Here’s a 5 shot group at 100 yards.

A 5 inch group.

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Bottom line:

The bullet is the most important part of your load. Nothing can be done to make bad bullets shoot well.

Start with excellent quality bullets if you want accuracy.

1 Comment on Educational Zone #153 – How to Develop Accurate Target Loads for a Rifle

  1. Glen T Shelby // January 11, 2016 at 1:30 am // Reply

    Nicely explained info. A lot of sites get wound up in high tec wordings that get a reader frustrated but I found yours quite interesting. Will try your routine for work ups.

    Thanks
    Glen

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