Featured Reloading Techniques for Long-Range Shooting John Brooks May 19, 2016 0 COMMENT Get the Lead Out Photography by Kenda Lenseigne Most people who start reloading for long-range shooting know at least a few who already do it, or at least read about it in their choice of periodical, website, etc. To us new guys, it seems like everyone else already has their pet load dialed in, and we’re left wallowing in self pity, staring at our bank accounts and calendars, just trying to make it all work. The mad scientist experiments from the myriad of reloading guide data just doesn’t seem to produce the results for us that everyone else is enjoying. While we spend hundreds or thousands of dollars in components and equipment, while essentially turning money into noise, we’ve all had that moment sitting at the press thinking, “There has got to be a better way to do this!” Fear not, there are two very effective methods of load development that will get you close to your own pet load, long before your throat ends up eroded halfway down the barrel. While the variables involved in accurate load development — along with internal and external ballistics — could fill tomes that would cram the libraries of Alexander the Great, we’ll stick to the basics, and assume you know one end of the press from the other. Creighton Audette’s Incremental Load Development Method (also known as the “Ladder Test”) and Dan Newberry’s OCW Load Development System (Optimal Charge Weight) can help make any new reloader a standout on the range, with all your friends asking you for your secret pudding recipe. While the two are similar and each has its own merits, there is a distinct difference on what exactly their ballistic focus is. The biggest differences between the two procedures are that one is developed based on velocity, or external ballistics, and the other pressure, which is internal ballistics. Since their inception, these tests have changed and evolved from shooter to shooter, but we’ll try to present them in their more basic formats, so once you understand the concepts, you can tailor them to your own needs. For both tests, ideally the only parameter to change is the powder charge. If you change the seating depth, primer, or point of aim, the data will be skewed and unusable. Also be aware that neither of these tests requires the use of a chronograph or weather meter, but both will make your life easier and the extra data can be extremely helpful later on. The Ladder Test The ladder test is a fantastic tool for beginners, but it requires access to a longer range, and either a good spotting scope or target camera system. The basic idea is that you choose (typically through powder/bullet manufacturer’s published data) what your estimated maximum charge weight will be and work your way down. For this ladder test, we’ll use the .308 Winchester cartridge for our examples, as it’s one of the most forgiving to load for and with a plethora of data available. For components we have IMR 4064 powder, Black Hills once-fired brass and Federal Match primers. Checking the powder manufacturer’s website, we’ve determined that an acceptable max powder charge for these components is 44 grains. Note on each case with permanent marker what the powder charge is to make organization easier. From our maximum charge, we’ll come down in 20 increments of 0.2 to 0.3 grains, ending up with a starting charge of 40.2. Now we’ll throw charges in 0.2-grain increments all the way up to our 44 grains max. Note on each case with permanent marker what the powder charge is to make organization easier. Pick a charge near the middle — in this case 42-grain, and load an additional five rounds. We’ll use these as sighters to zero our point of aim (POA) to our median point of impact (POI). With a large target board at least 3 feet high, draw two 1 MOA squares in the center vertically, side by side with a decent gap between them. One will be our sighter target, and the other our test target. You can place the target at 200 yards, but 300 is preferred. We’ll be measuring vertical dispersion, so putting a big ragged vertical hole at 100 yards won’t give us the data we are looking for. Two 1 MOA squares placed at 300 yards: sighter target (left), test target (right) Using your five sighter rounds, zero the group as close as possible to your point of hold on the square. I prefer to hold the lower left corner of the square, as it makes for a smaller, crisper target image in relation to my reticle. Switching over to our test square, and making no changes to POA, shoot the target, one round at a time in intervals that allow the barrel to cool adequately between shots. Heating the barrel with a string of rapid shots will exacerbate the vertical shift beyond reasonable testing parameters. After each round is shot, inspect each case for obvious signs of pressure. Very shiny ejector markings, primer cratering/flattening and a hard bolt lift will tell you you’ve reached your maximum safe charge weight and you should immediately cull the rest of the lot. I prefer to bring a bullet puller with me for this exercise so as not to just throw them in your range bag only to find them again later and inadvertently shoot them. Target cameras save a lot of time when developing loads. Using a quality spotting scope, a target camera system (or you can just lay your cell phone next to the target and inspect the video later), observe and record where each shot lands so after the string of fire is complete, you can mark on paper a sequence number next to each hole. What you should be looking for are “accuracy nodes” or clusters of sequentially shot holes that show very little vertical dispersion that put you in the highest velocity range without pressure signs on the cases. Which node you choose to go after is entirely up to you, but keep in mind that more velocity doesn’t always mean more consistency. Don’t worry about horizontal dispersion during this test — we’re only looking at the vertical component. The median charge weight from that accuracy node can be further refined with adjustments to bullet seating depth, primer selection or neck tension. From here, you can do another “mini-ladder” in different COAL increments or just go straight into grouping exercises and data collection at known distance (KD) targets. The Optimal Charge Weight Test The OCW is perhaps the easier and more practical method of load workup for reloaders with limited range and gear, as it can be accomplished at 100 yards, without a spotting scope or camera on the target. While the Ladder Test has been used by many reloaders for decades, and often to great effect, it has some flaws. Environmental variables will likely skew your results to some degree. For example, pulling a shot during the string, not giving the barrel an adequate time to cool or having only one representative of each charge might make for a more scientifically risky approach. The OCW dedicates a target to each charge weight, and it’s shot in “round robin” sequence (one shot on the first target with a charge weight, then a shot on target two with the next charge weight and so on), spreading the error factor across all groups equally with multiple shots of each charge weight, rather than the ladder test’s single shot. For this test, we’ll be using the same components again with our estimated max charge weight of 44 grains. Back off from max charge by 7 to 10 percent and load one test round with this charge. Add 2 percent to the charge weight and load another. Finally add another 2 percent and load a third round. These will be our sighters, and more importantly used to determine a baseline of pressure tolerance in your individual rifle. We should now have three sighter rounds loaded at 39.6, 40.5, and 41.4 grains. Add another 2 percent to the charge level of sighter round #3 and load a three-round lot with this charge weight. Add 0.7 to 1 percent to this charge (about 0.3 grains), and load three more rounds. Add that same graduation to each subsequent charge weight lot until you have moved one increment above your chosen max powder charge. So we will have: 3 x 42.3 grains 3 x 42.6 grains 3 x 42.9 grains 3 x 43.2 grains 3 x 43.5 grains 3 x 43.8 grains 3 x 44.1 grains At the range, set up your targets at 100 yards. The number of targets you use is dependent on how many lots of charge weights you loaded to include the sighter (to establish your POI on paper, as close to the bulls eye as possible). Be sure your targets are identical and level and your barrel should be clean before starting. After you’ve fired the sighters and confirmed that there are no pressure signs (ejector markings, primer cratering/flattening, or hard bolt lift), and have allowed the barrel to cool, you’ll then fire your first shot of the lowest charge group at target #1. Load a round from the next charge group and fire at target #2, then a round from the next charge group at target #3. Continue this “round robin” sequence until you’ve been through all the targets three times, allowing a cooling period between each shot and without changing POA. You should end up with a three-shot group for each charge weight. Watch for pressure signs as you progress into the hotter lots and fire the next charge only if there are no pressure signs on the previous charge. If pressure signs are encountered, cull the hot charge and all subsequent lots from the remainder of the test. You’re now looking for the three to four groups, which come the closest to the same POI on the targets. The trend of the groups should be obvious, normally going from low and favoring one side, to high and favoring the other side. However, along the progression, there should be a string of at least three groups that all hit the target at the same relative point. After you have carefully measured group sizes, distances, and directions from the POA, you’ll know which three to four groups come the closest to hitting the target in the same POI. You now choose the powder charge, which represents the center of this string. For example, if 42.9, 43.2, and 43.5 grains all grouped about 1.5 inches high and 0.75 inch right of the POA, you’d choose the 43.2-grain charge as your optimum charge weight (OCW). This will allow 42.9 and 43.5 to group right with it, making it a very pressure tolerant load. Avoid the urge to get sucked in to any tight groups outside the OCW range. You can tune any of the groups to be tiny by adjusting COAL, neck tension, or primer choice. After you’ve determined the OCW, you may want to try seating the bullets deeper or longer in 0.010-inch increments to see where your particular rifle does its best. Your next step would be to confirm your load recipe at the maximum range you will expect to use it. Load one round about 1 percent below, and another round about 1 percent above the OCW charge, and fire a three-shot group with these two charges plus the standard charge at the maximum range you will require the load to be accurate at. You should note MOA, or very close to MOA grouping. If you really want to get anal about the process, you can try both methods to see if your optimal charge weight and accuracy node aligns. Further refinement from these test results will see your groups getting smaller and smaller at farther and farther distances. It’s important to remember, however, that although modern rifle and barrel technology has come leaps and bounds in the past years for the practical/tactical shooters, there is a point of diminishing returns in reloading. Do you really want to spend that extra 1,000 clams in equipment to squeeze a hair more accuracy out of your loads and rifle? Set your loading bench up right from the start and you only have to do it once for the life of your barrel. Start slow, load safely, and deliberately and don’t get too caught up in the minutia. Once you’ve got your optimum load, fill some boxes and get out amongst them!