Ammunition Accuracy Requirements 101

Written by Sierra Bullets Chief Ballistician Tommy Todd

I load and shoot ammunition for a living. In my duties here at Sierra I constantly test bullet accuracy for our production needs. Because of this, I shoot a variety of different calibers and cartridges on a daily basis and a large demand of this shooting is keeping the guns and loads tuned for optimum accuracy. I have a very narrow window of tolerances to maintain in order to provide our customers (you) with the most accurate bullets on the market.

I have learned many tricks and techniques over the years to tuning a load, prepping brass, and cleaning barrels to keep a gun shooting. I often utilize the things I have learned and take them to extreme levels when competing in a shooting event.  I also often ignore most of these things (other than safety) and simplify the process if the shooting I will be doing does not warrant.

Recently I went on a prairie dog shoot in Wyoming with some good friends. The targets cooperated as did the weather with the exception of some challenging winds we experienced. We had a great time and make a lot of hits on those small rodents. When loading for the 223 Remington rifles and the TC Contender, I cut a few corners in the ammunition loading process due to both time constraints and accuracy needed. When shooting at a prairie dog a miss is simply that, but when shooting at say the X-ring at 1000 yard competition a poorly placed shot is reflected in both your score for that shot and placing in the match. Because of this, I can afford to miss an occasional shot at a varmint due to ammunition capability without worry but will not allow the same tolerances in my match ammo. For the Wyoming trip I utilized a powder measure and simply dumped the charges into primed cases that had been full-length sized and primed.

I had measured enough for length to know that while there was some variance all were under maximum length. I know there is some variation of the measure I utilized but not significant enough to warrant weighing every charge. When seating the bullets a competition seating die was used and I verified OAL on the occasional cartridge to make sure nothing changed.

The ammo produced shot under one inch at 200 yards in one of the guns I planned on taking on to Wyoming with me. I knew I had loaded ammunition that was quite suitable for the task at hand which was evidenced by the number of hits I was able to make at fairly long range.

Today I am loading ammunition for a completely different scenario. This weekend, I will be competing in the The Missouri State F-Class match. This is a six hundred yard match and some extremely good shooters will be in attendance. A person will not be able to lose very many points or they will not place well in the standings after 160 rounds for record. Because of the need for extreme accuracy I have taken equally extreme measures with the ammunition loading. I anneal the brass for this rifle every two firings. I clean the primer pockets every firing, the cases are checked for length and trimmed to exact length every firing. I am weighing every powder charge to the hundredth of a grain, (yes I am weighing to the kernel of powder). Rather than using a standard seating die and a loading press I am using an inline seating die with an arbor press and a gauge that indicates bullet seating pressure, what minor variation is observed in seating pressure is grouped together instead of mixed.

Every round is verified for OAL with an ogive comparator and any variation is culled. The work put into this ammunition serves two purposes. One is that the consistency gives very low extreme spreads which equals to very little vertical variation of the load and very good accuracy. The second product of all this work is the confidence that if I do my part the gun and ammo will shoot extremely good scores.

My point with this is that you must be able to load ammunition that is equal to your need of accuracy. If you are shooting at water balloons at 200 yards your ammunition doesn’t require weighed charges and frequent case annealing, but if extreme accuracy is required if you take shortcuts with your ammo it will show up on target. If you have questions or want more information on loading for extreme accuracy visit our website or call and visit with our technical department – 800-223-8799.

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7 Responses to Ammunition Accuracy Requirements 101

  1. Daryl says:

    I have a couple good teachers as well, Brian Litz and John Pierce. and I shoot Pierce built rifles when hunting. I load primarily Bergers but I do load your pills as well.

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  2. Brittius says:

    Reblogged this on .

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  3. firstriverbend says:

    Very good article and illustrates that different scenarios tolerate different requirements! Too many times articles are written without any real understanding or reflection on what the needs of a particular shooting environment truly is, some times causing angst for no good reason.
    Popping prairie dogs, as compared to the needs of F-class is a great way to illustrate the real world of shooting. 🙂
    One is much better served using the time it takes to make “laser” class ammunition, only to be used on a steel gong at a relatively close range, and instead use that “wasted” time to learn more about the mechanics of shooting!!
    Minute of prairie dog or minute of gong shooting does not require the same quality of ammunition as true target shooting for score, thanks. 🙂

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  4. Dave Guthrie says:

    Well written common sense article. Im a hunter but an accuracy nut. I use many of the same techniguesmyselself. I do weigh each charge, i trim every time i load amd i anneal every other time. The need for benchrest accuracy requires more work than im willing to put in but i do put in the time tweaking powder charges and seating depths to find that perfect node. In my hunting rifles the little extra work usually results in sub 1/2 MOA accuracy.

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  5. Robert Ruder says:

    Great article Tommy.
    Here is something you mentioned that I wish I would not have seen. Now I want one!! Quote: “Rather than using a standard seating die and a loading press I am using an inline seating die with an arbor press and a gauge that indicates bullet seating pressure”. End Quote.

    That being said: I do ALL the things you mentioned for competition, except I cannot weigh to 1/100 of a grain, and that arbor press/&gauge. I had also neck-trimmed my cases with a Forster setup). I load with a Forster Micrometer bullet seating die in a Forster loading press.

    I do anneal, sometimes every loading AND use a Lee collet neck-sizeing die with a rod slightly over sized so as to have a medium tension on the bullet. Even at that, taking my time, I can “sometimes” feel the bullet going in with a little more resistance than others even after annealing and neck trimming.

    I don’t hunt anymore, at age 76 .. and bad knees. I only shoot at 100 yards from the bench and put the creaking knees to work only twice. I hang the target and retrieve the target. At 100 yards I can see the .22 cal. holes/groups shot with my 21 power scope. I have never shot competition EXCEPT, every time I go shooting, “I compete against myself”, ….. by knowing what my 22-250, and myself have been capable of in some of the past sessions, and try to do even better.
    Bob…in Indy.

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  6. John Snell says:

    Each to his own. For my bolt guns I use the Rock Chucker to F/L size new brass to fire form, and that’s all. After that I use the Wilson’s exclusively for neck sizing and bullet seating. I put in the effort to ream flash holes, uniform primer pockets, outside turn the necks to remove only the amount necessary to achieve the average neck thickness, and trim cases and chamfer precisely, annealing will occur every reloading as soon as I get a machine, but for now it only occurs when I can feel the bullets seating with a particular ‘feel’ that is unique to using the arbor dies (in 308 that is likely to be around 10 reloads, in 204 around 5-6). I find I’m just as fast with the arbor dies (maybe even a bit quicker), and I get to see, feel, clean and inspect each piece of brass several times during the process. On reloads, I don’t clean the cases. I decap and neck size, using only an extremely tiny amount of dry graphite, I quickly remove primer residue using the same K&M tool that uniformed the primer pocket, hand prime, meter the powder from an RCBS Chargemaster, and seat the bullet. For me, and particularly for my bolt guns, I don’t know what each shot is going to be fired at ahead of time, and I want every single round to be as precise as possible because I may only get one shot. For my gas guns I usually shoot factory ammo, and accuracy is a secondary consideration to dynamic training.

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