How do you prefer to vary the powder charge when looking for best accuracy? Assuming that you have picked a set of components and already worked your way up so that you know the book max is safe in that specific rifle - what's your method of finding the best accuracy just by changing powder weight?

When I am doing basic pressure tests, I don't really pay attention to shooting my best for groups. I typically will load two at each charge and work through them just looking for pressure signs, velocity, etc. I usually go back later and do more precise work for accuracy. What kind of charge increments do you use? Is .2 gr a small enough adjustment? I like to start at the max charge and work down in .2 gr increments until I am maybe 2 gr below max and see what charge gives the best group. What kind of system do you use?

Dang! You just read my mind! Exactly! Nate

Iusually start about in the middle between min and max loads and work up about 1gr each. I make 6 of each and shoot them. Whichever shhots the best, I will make 6 more 1/2 gr below, above and the same. All my rounds are for hunting so that is close enough for me.

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I like to start at the max charge and work down in .2 gr increments until I am maybe 2 gr below max and see what charge gives the best group. What kind of system do you use?

Yup, me too. Except I page through every one of my loadbooks all the way back to 1970 and find the one which lets me cram in the most powder, then work down from there. Safety and proper handloading practice be damned!

I recently started toying with the Ladder or Audette Method. Figure your range between starting and max loads, load ONE load each in .2 grain increments if case capacity is below 50 grains of water, .3 grain increments if above....shoot all at 200 yards or longer in order, at the same target, watch for your pressure signs along the way if you want. The process identifies harmonic nodes in the barrel vibrations, shots will cluster at points in load progression, both at the top and bottom of the barrel oscilation. The loads that cluster in the low node(s) below max charge is your winner. Fiddle with voodoo at that charge level...

Yup.

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Safety and proper handloading practice be damned!

Who said anything about bad practices? This is AFTER a proper safety workup to make sure that the book max is safe in the rifle. If the rifle says max is at some other lower level, then that is the max. I just don't want to begin with the starting loads and work all the way up the range in .2 gr increments. I'd rather start at the known safe top and go down to find best accuracy with best velocity.

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Originally posted by DigitalDan:
I recently started toying with the Ladder or Audette Method. Figure your range between starting and max loads, load ONE load each in .2 grain increments if case capacity is below 50 grains of water, .3 grain increments if above....shoot all at 200 yards or longer in order, at the same target, watch for your pressure signs along the way if you want. The process identifies harmonic nodes in the barrel vibrations, shots will cluster at points in load progression, both at the top and bottom of the barrel oscilation. The loads that cluster in the low node(s) below max charge is your winner. Fiddle with voodoo at that charge level...

+1, sometimes at 300 yards though

Method employed and increase in powder charge between test rounds depends on what kind of loads I'm developing.

For (small) cartridges to be used for target-type shooting (.222 Rem, .223 Rem, 6mm PPC, 6mm BR etc), I'll normally use the "OCW" (Optimal Charge Weight) method, which is a modificated Audette/Ladder method as mentioned above. The guy proposing the OCW modifications used to post here, I don't know if he still occasionally does?? For these type cartridges, I normally move in steps of .2-.3 grs powder increments. For these cartridges, accuracy is the aim, not muzzle velocity. So light loads are accepted, and even to some extent preferred for longer barrel life.

For hunting-type cartridges (.270 Win, .30-06 etc), I normally load 3 rounds of each charge weight with increments of .5-1 grs. Then I shoot 3 shot groups to establish any pressure problems, and to check for charge weights worthy of retry/verification of good accuracy. For most hunting rounds, I want to achieve safe loads, but preferably stay in the upper part of the load interval established by manuals. I will accept lower accuracy for higher velocity - although all within limits. Any load capable of shooting 3 shots at or below 1"@100 yds, is certainly accurate enough to go hunting big game with. Now it just needs a good trajectory as well, thus the emphasis of staying (safely) towards the top of the load interval.

- mike

I usually start with the recommended starting load and loasd 5 rounds at each charge level, increasing in .5-grain increments. (ALL my ammo is for hunting, noit target or varmint rifles.)I next shoot each load for group, then select the one which groups best as "the load" even if it is less than book "maximum". I then load up 20 to shoot for verification of accuracy performance and also velocity testing. This is to make sure the first good group was not just a fluke. This is of course provided none of these 5-shot test lots shows unacceptable pressures. If any of these 5-round batches does show excessive pressure, I drop back from that level by 5% and consider that the max in that rifle. If accuracy is unacceptable at that level, I start over with a slower powder.

How do I determine "unacceptable pressure"? Any load that permits the next new primer to enter the primer pocket easier than the previous one did is too much pressure. I expect at least 10 reloadings out of a new lot of cases before they start failing. Otherwise the load is too hot.

I move up from recommended start to max (or my desired velocity, if different) in one-grain increments checking for pressure signs. That's three-shot groups fired as I would fire under hunting situations, i.e., cooling between groups, but not between shots.

I check for basic accuracy in the lower range, but not seriously, as mostly this is a safety check. I record the accuracy from the above-halfway up level, as these are candidates for hunting loads.

When I get to my desired-velocity, usually there has been a load that I'll want to explore and will load 10 rounds for next time. If I'm feeling really energetic, I might vary the jump-to-lands in 0.003 increments, but this usually isn't necessary for my purposes.

My approach differs from some in that I'm aiming at a desired veleocity, then I'll adjust the vibration nodes with bullet jump, not powder weight changes. I'm more likely to change bullets than powder, BTW. Life's too short for complications...

Jaywalker

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Who said anything about bad practices?

I did.

Like you, I can't be bothered by working up in .2gr increments either. You asked for other's opinion. I gave mine. Take it or leave it.

I start a grain or so above minimum, and load four of each. That allows for five powder variations in a box of 20. I load in half-grain increments, and shoot each of the four at a different target. Typically, one of the five loads will group significantly tighther than the others. That is what I load. If pressure signs get bad before I get to the top load, I stop at the closest group without overpressure signs.

I start with a fixed powder charge, usually 1 to 1.5 gr below max. I then load 5 at .005" off lands, 5 at .015" off, .025" off, Etc out to .055" maybe. I shoot them and usually will find a good grouper. I then load 5 of the same, plus 5 that are the good length + .005" and 5 at -.005" and take them to the range and shoot them. By now, I have a good idea what bullet jump distance the gun prefers. Now I take that length, and load 5 more, then 5 at -.1 gr and -.2 grs, +.1 gr and +.2 grs. Back to the range to see if the change in charge makes a difference (not as much as I would have suspected before doing this for about 50 different rifles). After shooting these, I sit back, evaluate things and select what seems to be my best load. Then, I load 15 of that load, back to the range to verify it shoots as good as the prior targets indicated. And, if you are really into small changes in variables, you can to the +/- thing with seating depth in .001" increments up and down.

Where did I come up with this--From the old Arnold Arms web site which is no longer in existence.

I dig through the reloading manuals paying particular attention to the posted accurate loads and their velocity.
I may use one of their loads as a starting point, meaning I'll bracket my first ladder test with their load at about the center or I may reference the burn rate charts an pick something else that looks like it should give me 90-95% case capacity and use it's equivelant as the center of the ladder.
At the range I click off about 1 1/2 inches left windage so I don't shoot out my aim point. (I only have acess to a 100 yd range.)
Give the barrel a good 5 min between shots. More if it's hot.
Normally there will be 4-6 shots that group real tight. Use that info to do an OCW round robin test. 2 range trips normally gives me what I want if I did my homework right and the greamlins stay in the shadows.

Well here goes. I look up the load in every reloading to see if there are powders or loads that give better velocity or accuracy. I then start 1 to 2 grains of powder off max. I shoot three shot groups through an Oehler 35 chronograph. I am looking for loads that have satisfactory velocity, a low standard deviation and something less than 1 minute of angle accuracy. I usually adjust loads at .5 or .2 grains until I find a load I like or I see pressure.

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I just don't want to begin with the starting loads and work all the way up the range in .2 gr increments. I'd rather start at the known safe top and go down to find best accuracy with best velocity.

Just because a load is listed as a max load in a manual does not mean that the load is safe in your rifle.That is why you work up from a starting load.I work my loads up in 1 grain increments and look for a load that shows consistant accuracy when the powder charge is varied by a grain or two.These loads have proven to be much more stable in changing climate conditions than loads whose accuracy changes significantly when the powder charge is changed slightly.

I'll load several to get close to a max load and check accuracy as I go. I like to find a load where group size doesn't hardly change as the charge weight changes. When you have a load that with a .4 grain change in charge doubles the group size, changes in weather, etc. may make the load inconsistent. I like to find one where small changes in charge are insignicant to the group size if possible. My load with H4114 in my .220 AI will shoot in the .2's on a good day, but you can load five shells from 45 grains to 47 and it will still shoot the whole bunch in .7. That's a good hunting load to me.

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Originally posted by Fjold:

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Originally posted by DigitalDan:
I recently started toying with the Ladder or Audette Method. Figure your range between starting and max loads, load ONE load each in .2 grain increments if case capacity is below 50 grains of water, .3 grain increments if above....shoot all at 200 yards or longer in order, at the same target, watch for your pressure signs along the way if you want. The process identifies harmonic nodes in the barrel vibrations, shots will cluster at points in load progression, both at the top and bottom of the barrel oscilation. The loads that cluster in the low node(s) below max charge is your winner. Fiddle with voodoo at that charge level...

+1, sometimes at 300 yards though

+2, at 300yds when possible.
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For any Beginners or Rookies reading this thread, let me encourage you to ALWAYS develop a Load from Below, not as some have suggested by starting at or above MAX Loads shown in the Manuals.

If a person is too busy to do it properly, then it is best to just put off Reloading until you do have some time to do it correctly.

quote:

The process identifies harmonic nodes in the barrel vibrations, shots will cluster at points in load progression, both at the top and bottom of the barrel oscilation. The loads that cluster in the low node(s) below max charge is your winner. Fiddle with voodoo at that charge level...

In the shot string, I guess the highest cluster in the string represent the low node??

Thanks for the thread, I have found it to be very informative.

I have an interesting series of 6 targets that was shot yesterday. Everything about the loads were identical except the powder charge. The bullet was a 55 gr. Sierra and the rifle was a custom 22-250 Mauser Varmint weight barrel.

s-s target Had one shot of each of 5 different loads. At fifty yards the group measuered .460" The group formed a slightly irregular L.

#1 target, 38.5 gr. accurate data 86, 100 yds. 5 shot .745" group. avg. point of impact 3/8" at 9 o'clock.

#2 target, 39.5 gr. 86, 100 yds. 5 shot .870" at 1/4" 3:30 o'clock.

#3 target, 40 gr. 86, 100 yds. 5 shot group .495", 4 shot group, .200" at 1/8" at 7 o'clock.

#4 target, 40.5gr. 86, 100 yds.5 shot .360" at 1/2" at 3:30 o'clock.

#5 target, 41gr. 86, 100 yds. 5 shot 1.600" with the avg. point of impact at .600" at 3:30 o'clock.

If I knew how to post the targets I would as it is an interesting portrayal of powder load variation affecting group size and point of impact. I can E-Mail them if someone wants it or wants to post it.

As a point of interest my buddy was going to get rid of this barrel before he used the Accurate data 86. roger

Old age is a high price to pay for maturity!!! Some never pay and some pay and never reap the reward. Wisdom comes with age! Sometimes age comes alone..

I'll load two groups of 5, for a total of 10, with each charge weight, say 10 for 25 grains, 10 for 26 grains...

Then at the range, I shoot two 5 shot groups to see which one is better....

Little more involved, but it pays dividends.. by knowing what you have with that rifle.....

I will also test up to 15 different types of powder with one rifle.. and one bullet weight at times.. you notice patterns.. on what works....so it can eliminate some testing...

one my 6mm Rem, I tested 15 different powders...with a 75 grain Hornady HP which is what bullet I will be using for long range prairie dogs...

All were minute of prairie dog, except the last group, with H 414 load of 47.5 grains...It was a one hole shooter...I'll post the results in a separate thread... it surprised me....

But the results and knowledge were worth it!

cheers
seafire