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Old 01-30-2013, 3:47 PM
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Quote:
Originally Posted by blockfort View Post
I'll be testing my new 308 loads tomorrow at 100y. I'm a relatively new rifle shooter, and I only have a 3x-9x scope. I don't want to push it to further distances.

Should I shoot 3-4 rounds of each load and measure group size, or should I use the ladder technique to find the best load range?
I think it depends on what the ammo will be used for. If you're looking to shoot long range (800 yds +) then your not looking for one hole accuracy. If your a bench rest shooter then your looking for bragging rights as to who has the tightest groups.

If your long range, then your going to be loading to as close to max powder load as possible. I'd start with a ladder test with a string of rounds loaded in 0.2 grain increments from 2 grains below max to the first step over max. Check for pressure signs after firing each round and stop at the first sign of pressure dangers. And, shoot your ladder at least 200 yds, preferably 300 yds.

What you're looking for is consecutive loads that fire at similar vertical height. Don't be concerned about rounds that string left to right, those are probably you. You want the 2-3 rounds the shot the lowest moa vertically. That is your power node. Pick the middle load and load for that round, and if your loading is off a 10th of a grain or two you'll still be hitting at that node range. Remember your shooting long range so you only need a round that will consistently give you 1 moa at 1000 yds or 10".

As a new shooter, you may want to run the ladder more than once to have a better chance of taking the shooter out of the equation. But only shot one round of each weight per ladder. Your not looking for the tightest groups by load but the tightest node.

Now if your looking for one hole accuracy, I'd suggest setting up 4-5 six to eight inch targets on one target stand at 100 yds. Load starting 3-5 rounds at the recommended starting load and in increments of 0.3-0.5 grains. Shot round robin, one round of each weight per each of the targets. Then return to the start and shot the next string. That will take the odds of your having a better than average string with one load weight.

After the first set of loads are complete, you can load a new set of targets and move on to the next 4-5 load weight. Don't rush thru, as that will only overheat the barrel and taint your results.

Your not looking for bullseyes, since each load will have a different trajectory, your just looking for the tightest groups whether they are above or below the POA. If you find consecutive (2) groups that are better then the rest, that will be your accuracy node. Go back and load 5 rounds in 0.1 gr increments starting 0.2 grs below the first target and ending 0.2 grs above the 2nd. Find the tightest grouping of that string, and you have your load.
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