Really basic stuff about working up loads for accuracy

I've futzed around with working up loads in the past, but I always get the feeling that my loads aren't as accurate as they can be due to my shooting.

What do you folks use for working up loads?

In particular, I want to work up Hornady 55gr FMJBT loads w/ WC844 for my 20" AR15 Service Rifle

Now, this rifle doesn't have a scope, just match sights- is trying to work up loads with irons at 100Y just a wash?

I also have both the Caldwell sandbag rests as well as the lead sled- any tips or pointers on how to set everything up for the best possible group measurement?

Thanks!

When I work up groups from scratch, here is my method:

I load up 10 rounds in each 0.5 gr increment across the safe range of the powder. e.g. 23.0, 23.5, 24.0, 24.5, 25.0 (made up numbers...not for your powder)

Then I go to the range and test fire the rounds at 50yds over a chrono. I also use a front rest, rear bag, and iron sights.

I focus on making each shot as consistent as possible. Then I take all the targets, label each with the load data and shooting conditions, and go home to analyze the results. I scan the targets into the computer and use On Target to measure the groups. I compare the best two groups and their chrono data.

I take the best group and work up loads 0.2 and 0.4 gr above and below that charge. e.g. if 24.0 is best I will load 10 rounds each of 23.6, 23.8, 24.0, 24.2, and 24.4

Then I go back to the range and test fire all the rounds over the chrono at 50yds.

I go back and analyze the data same as before. This time there is a bigger chance of rounds being close in results. I compare the best two and load 10 rounds of those charges. I take those rounds back to the range and try them at 100yds. You should be able to decide on a clear winner out of those two as the distance opens up.

I don't have a chrono

However, unless I'm misunderstanding something, any st-dev in chrono measurements for a given load is due to slight inconsistencies in the cartridge and does not necessarily have anything to do with finding that sweet spot in the barrel harmonics?

Do you guys have any advice for which kind of target to use? I've been using the free targets available at mytargets.com- the one with a 1" red box in the center.
I do have some difficulty with just sight alignment at 100Y against a small box though- any suggestions on which targets are optimal for loading iron sights @ 100?

with iron sights you are only going to get so so results in my opinion. with a scope you can be fairly certain you are aiming at the same point each time. i use a lead sled when i am working up

loads to take me out of the equation. and i do pretty much the same as ajroyer for ladder testing.

point i am making is i know how good i am not with iron sights so there is no way i could develope loads at 100yds with out an optic. because you can't tell if it is you or the load causing the size of the group.

I mostly use the chrono to decide how consistent my reloading is and what velocity is producing the most accurate results for the specific round.

Any target that you can aim at consistently will work. I use the 25yd bullseye pistol target because I can see the big black circle and aim at the 6 o'clock position out to 100yds (and because I have plenty of them). If you have a hard time seeing that target, try the 50yd target (or even a paper plate). The goal is testing how the bullet groups and not necessarily if you hit the X.

If you have a scope or can borrow a scope for your rifle, you can use the diamond on the grid and fine tune your results.

Whether you use iron sights or a scope, the important thing is the group. The most accurate round with iron sights is also the most accurate round in the scope. Iron sights may not put them all through the same ragged hole, but you can tell that it is the tightest group. After that it's just time to shoot.

will your loads show appreciable differences at 50Y though?

All good advise so far.

Since you are talking service rifle I would like to point out that some of the loads/bullets that are super accurate at 200-600yards are not necessarily better than fair at 50 . According to the hot shots many (some?) of the best long range bullets slop around and take a bit to settle.

Not sure what Hornaday 55 gr bullet you are looking at but my thinking is for any competition (even for a rank beginner) you should be using
proven match bullets . Price difference per box is significant but for the amount you use for a match and practise it doesn't work out to a whole lot. The other benefit of the match bullets is that if you ask around of the competition guys they are pretty much all using a few common bullets and powders and similar loads. No need to re-invent the wheel , many high end shooters have fine tuned match loads for any type of possible
competition . Yes you need to work up those loads with your gun but unless you have unlimited time and money I feel your best bet is to aim towards what has worked for the hotshots

I am a lazy old fart and generally only shoot service rifle on a reduced 100yd course and found that in my off the rack RRNM rifle the 52GR sierra match king with suggested loads is a tack driver.

The Sierra loading manual has much info on select competition loads and I have found that info to be a great shortcut to loads that have worked very well for me.

Many suggest the light 52 or 53 grain sierra for 100 yard courses and the old standby for standard full courses is the 69 sierra. many guys will use the heavier 70+ gr bullets for the slow fire single load parts of the match which entails loading them longer than magazine length


Hit the training button and look in the specific compettion boards for more specific information

Yep, I already have a load for Hornady Match 75gr HPBT for reaching out to 600Y

No not much if any. With iron only sights I work up only at 50 yds until I find what load has potential. Then I check a group out to 100yds. If I like it, then I fine tune OAL etc.

To Add... When I work up loads using scoped rifles. I use the Audette method aka Ladder method with great results. Another I have also use is the Optimal Chage Weight method. (Google both)

This is a common misconception driven by spotty anecdotal evidence... I am an aero ballistic engineer at ARL and have a very good understanding of how projectiles fly. While what you refer to as "settling" does happen with all spin stabilized projectiles (btw it is more pronounced with VLD bullets) there are two things going on. First is the damping of the pitch and yaw motion as the bullet travels down range the second is caused by the first and is the epicyclic swerve which causes the projectiles center of gravity to swerve around the flight path. While this is very real the magnitude is to small to cause this phenomenon. This can only be tested by shooting through two targets (the first being acoustic) which has been done and has not shown this effect to exist...a better explanation is given by Brian Litz in his book and is parallax of the optics (not an issue with irons)...there is to much anecdotal evidence to ignore and Litz's explaination may be right however there may be something else going on the big thing is that it is not physically flying in tighter groups at longer ranges. This has been proven with Doppler radar testing as well as acoustic targets that yield multiple groupings at multiple ranges with the same bullets.


Just thought I would clarify this

Here is an example of what difference you can see at 50yds:

For what it's worth, military high power shoots 77gr SMK across the course and civilian HP shooters tend to like 52gr SMK for 200yd to 300yd. A lot of guys also use 69 gr SMK for 600yds, and some use it across the course. I have read conflicting reports on Hornady's 75gr, but haven't gotten around to loading it yet.

Also, 55gr VMAX were slightly under 55gr on my scale and Sierra 55gr BlitzKing were almost exactly 55gr. The biggest difference (other than the quality control for weight) is that the Sierra 55gr BlitzKing has a boattail that makes it easier to load in the case and helps improve ballistics beyond 200yds.

So many people rave about the Hornady 55gr FMJBT that it is next on my list to try out.

I work-up loads with my iron sighted pistol at 100 yards. You must have confidence in your shooting ability, whether you are using a scope or not. If you can shoot sub-moa with proven loads then you should be good enough to load develop.

When I load develop, I use a sandbag in the front and a beanbag in the back on a shooting bench.

H4895 Ladder Test

Also, the Audette Ladder Test saves on components, I usually find a load within 10 shots.

H4895 Load Test

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