How to find your most accurate load FAST.

[SaskShooter]

Maybe some of you have already heard this, but for those who haven't, I'm gonna share a bit of advice an old timer shared with me a few years back.

We chatting at the trap range where I worked, when we got to talking about our varmint rifles. I mentioned I was having a hard time finding a good load for my .243, and he smiled, leaned in, and said quietly "Lemme tell ya a little secret..."

First, start at your minimum load- let's say 57 grains (I just finished doing this with my .300 Win mag). Load one shot with 57 grains of powder, and number it "1" with a Sharpie marker.

Now, look at your recommended max load- to make it nice and even we'll say 61 grains. That's five grains difference between max and min.

Load four more shots with 58, 59, 60, and 61 grains of powder in each, respectively. Number them "2" through "5".

Now, aiming at one bullseye, shoot all five shots in order 1-5. After every shot, circle the bullet hole, and write the number of the shot beside it.

Finally, look at your five-shot group. Whichever two shots hit closest together will be close to your perfect powder charge. You can fine-tune from there, working up from the milder of the two shots.

Obviously, this is no magic trick, and it won't work in ALL scenarios, but I've found it to be a real time saver.


When you've got a really accurate rifle (like the one I built and shot this group with) the results should look something like this-

You can tell, my most accurate load will be somewhere between 58 and 59 grains.

 

[Stanm70]

People shoot several rounds of each load because it reduces outliers and provides a consistent average. I wouldn't be confident enough to just shoot one of each load but my hats off to you if you can!

 

[SaskShooter]

Well, it's a quick way to get very close to the perfect charge weight without burning a lot of ammo or heading back to the loading bench.

 

[Lefty7mmstw]

I've done that when I need to find a safe charge with mil-surp powders. I'll walk it in (charge weights) until they start clustering, that's when start loading groups and shoot until the velocity and accuracy fall in. Often you can get it done in under 20 shots including proving the group with at least 5 rounds in one group.

 

[Dr. Vette]

I've done it at 200 yards because it gets you more distance between your hits on target and therefore a bit easier to say where your node is. Usually 7-9 loads set up, and go from there.

The "3 rounds of each load" always seems to be too much data which just gets you confused.

 

[Mikecr]

All it takes is a seating adjustment to screw up that plan, and if you don't have best seating, you probably don't have your best load either. What you might have is best for chosen seating only. There is also the formed status of your brass. If cases aren't fully formed and sized to stable, load development isn't done -until this is met and shooting best with it.

 

[lloydsmale]

Only way ive found is to shoot ALOT of different combos. Id dearly love to find a differnt way and save some money but i doubt anyone will ever come up with a better way then shooting groups.

 

[Joseph Bowden]

I believe it is called laddering.
I was taught to do it with five bullets each and see witch two groups are the closet together. Yea I know witch is spelled wrong.
Joe

 

[boomtube]

What you're doing is basically a short range ladder test, I've been doing it for years because my range length is limited. It works fine to get close to right and does it quickly with minimum component waste, that's all anyone can expect from initial load testing. As you suggest, now it's time to start working in detail from 58 to 59 gr.

 

[joe0121]

What the op described is the OCW method only a shorter version.

 

[Bart B]

I've just used the same load others used in my match rifles. All the barrels for the same cartridge shot good enough to win matches with the same load. About 1/3 MOA at 300, 1/2 MOA at 600 and 3/4 MOA at 1000; at worst. Half a dozen or more .308 Win. barrels and four 30 caliber magnum barrels. I never worked up a load for each new barrel. Only once did I work up a load; a new Sierra bullet was introduced and I was part of a group developing loads for it.

I'm convinced most folks do not test their loads nor evaluate the groups shot properly. First off, you gotta shoot at least 20 shots per group to have it be meaningful to at least 80% confidence all groups will be no larger. Second, accuracy you can count on is the largest group shot with a given load. A rifle that shoots 5 groups from 2 to 5 units of measurements is more accurate than one that shoots 5 groups from 1 to 6 units of measurements. The 20-shot composite of four 5-shot groups will be larger than the biggest single 5-shot group. Most important, whatever shooting skills one has will be added to the accuracy of the rifle and its ammo. Nobody shoots a rifle and its ammo as accurate as when the rifle's clamped in a free recoiling test fixture. All of which is why I belive there are dozens (hundreds? thousands?) of "most accurate" loads for a given bullet and cartridge combination.

 

[limige]

Pretty much a ladder test but cut down too short. IMO do the same but 1/2 gr increments two of each so you can do the test twice. Load them .02 off the rifling if your mag allows. Otherwise use saami length. Then shoot it at the longest range you can manage preferably 300 yrds or better.
Then you should have a good idea what nodes to use. Do a seating test and fine tuning with powder.

 

[Mikecr]

ACCURACY has nothing to do with PRECISION.
It takes only single shots to define accuracy, which is what matters in long range hunting.

1/2 moa of grouping, -somewhere on paper, no matter the number of shots, won't help a hunter one bit.
1/2moa of accuracy,, cold bore,, now this is a different matter.

 

[Lefty7mmstw]

ACCURACY has nothing to do with PRECISION.
It takes only single shots to define accuracy, which is what matters in long range hunting.

1/2 moa of grouping, -somewhere on paper, no matter the number of shots, won't help a hunter one bit.
1/2moa of accuracy,, cold bore,, now this is a different matter.

Yes, but you have a chicken and the egg situation here. I don't care a bit if I can drop the first round of the day into a certain spot at 500yds (or any given yardage). The first shot is terribly important, but so are the following rounds.
I want the first ten shots hitting that spot so I have reasonable confidence in a follow up shot should said critter decide to run and I have to feed him more lead for breakfast. It's happened to me more than once where a 1 pill diet isn't enough and as such a rifle only capable of 1 good shot is simply a crow bar to me.