What I find somewhat baffling, frustrating and borderline amusing is that 50 years after I was first exposed to reloading for rifles, there has yet to be any standardized consensus on how to go about load development. Most of the reloading manuals will tell you to do load development, but aside from the 5 or 6 basic steps required to put something together that goes BANG, specific how to do effective load development steps dry up in a hurry. So guys are left wandering in the wilderness trying to cut thru all the noise to find something that works.
So if it were up to me to put one together, it would go something like this:
Step 1: Know the limits of your rifle. In general, budget rifles off the rack do not have the same accuracy potential as high end custom jobs, so temper expectations. Use factory ammo as your benchmark. If it won't shoot factory ammo worth beans, hand loads alone won't do much better. Load development should be performed on barrels free of any fouling, copper or carbon, as fouling is a variable that has potential to skew the results.
Step 2: Form follows function. When selecting a bullet to test, match it to the end use. Hunting or target, long range or short. Hunting bullets, in particular, need to be matched up to expected hunting conditions. Hunting bullets have an optimal impact velocity, so pick a bullet to match expected range and velocity where it will be used. At this point you also need to determine your end game goal. Is it optimum accuracy at any velocity that is reasonable? Or to make ammunition that is equal to or better than factory ammo of same use. Same or better accuracy and velocity.
Step 3: During any load development work, best results will come if you eliminate as many variables as you can. Pick the components you want to use and stick with it. Same lot of brass, primers, powder and bullets. The bullet is the driver. Once you pick a bullet, you can chose any components you want to go with it, but once you select the set, you stay with it. You should be able to get to an end conclusion with one bag (50 pieces) of brass, one 100 count sleeve of primers, one 100 count box of bullets and one pound of powder. Be aware that new, unfired brass, even from the same lot, creates a variable that may differ from end result after brass has been fire formed to fit your chamber. Consistency should improve after brass has been shot once or twice.
Step 4: Using fire formed brass as a guide, setup full length sizing dies to bump shoulder from 0.001 to no more than 0.002. Size all brass, fired and new. For any bullet being used, determine COAL that results in bullet jump of 0.020 to lands (assumes rifle barrel is not shot out and has remaining life left in it) and setup seating die to seat bullet of choice to this level (20 thousands off the lands). Seating depth may be tested and altered later, but for now, eliminate the seating depth variable so as to be able to determine optimal powder amount.
Step 5: Experience has shown that best consistency, accuracy and velocity often are found with powder charges near full case capacity, which means reloaders are often walking the edge of what is safe to use. As such, it is critical that reloaders learn and understand signs of pressure. You need to know when you have reached the safe limits of the loads you are working on. Accept they may be more or less than what published data suggests. Stop when you reach obvious signs of pressure, even if there is room in the load data to go higher. Conversely, if you are seeing no signs of pressure, you may be able to go higher than maximum until you do. Depending on load data sources, there are differences in what one source says is maximum vs. others. Your actual results will mean as much as numbers on paper. And remember, this is driven by your end goals. If you have reached good accuracy at factory level velocity or better, and that is your goal, then you do not need to go any higher into the danger zone.
When searching for load data, try to find at least 2 or more independent sources for the load combination you are working on, as these do vary, and sometimes by a lot. From these different sources, conclude what you feel is a reasonable maximum load for your components.
Step 6: Once you have selected a load combination to try, load 3 rounds each at 6 different load levels. Load increment for this 6 step ladder is up to loader, but a good place to start is 1% of max load in grains, rounding down to next whole number.
Example, if max load is 42.5 grains, then 1% is .425 grains, rounded down to .4 grains. If one began at the maximum and worked their way down or backwards, load increments would then be:
6: 3 x 42.5
5: 3 x 42.1
4: 3 x 41.7
3: 3 x 41.3
2: 3 x 40.9
1: 5 x 40.5 (3 shots plus 2 foulers)
End result is one 20 round box of ammo to test, consisting of 2 fouling shots and 6 incremental loads of 3 shots per load.
This differs from the standard recommendation where one starts 10% (i.e., 4.3 grains) below maximum to get to minimum or safe starting place. Instead it is only a 5% reduction from maximum, which in most cases remains safe. It also cuts to the chase much faster. If the two fouling shots show no signs of pressure, one can safely continue on up thru the ladder. Continue until you shoot all 6 loads (reach maximum) or if signs of pressure are found, stop at that point and go no further.
Step 7: Shoot loads at 100 yard targets, shooting for best accuracy and if possible, use a chronograph to measure and record velocity. Shoot the rounds round robin....1 each from loads 1, 2, 3, etc then if you make it all the way to #6, start over. Some rifles (perhaps light weight sporters with pressure point bedding) will demand you allow barrel to cool down between shots so as to not distort the results.
Step 8: Examine completed targets for best accuracy (smallest group) along with correlation of velocity (extreme spreads). Assuming velocity, both amount and consistency) is acceptable, most accurate group wins.
Step 9: If best group is acceptable as is, then one can stop load development there and you are done. If it looks good, but you want to pursue this further, you can then enhance the load development process by going above and below the selected load in 0.2 grain increments (2 loads of 3 shots each, shot round robin). You would then be left with 5 loads shot in 0.2 grain increments, clustered around a level that gave you the best velocity. Pick one you like and you are done.
Step 10: If you want to continue fine tuning the development process, you can do the same thing as before with the single variable now being seating depth. Load 3 rounds each of your selected best load from powder charges, but now increase the seating depth of each by 0.003 (three thousands). That would have you starting out at 20 thousands off the lands (you already have that group), then load and fire 3 rounds each seated at 23, 26, 29, 32, 35, etc. off the lands for as far as you want to go. Expect groups to open and close as you pass thru seating depth nodes. Final seating depth should be at entry point of a node, which gives the most life to a load, as it will continue to work as lands erode away until such time as node is lost.
End result is a load specific to each component combination. Change any one component (and especially bullet or powder) and you start over from the beginning.
Something like that.
