I have been loading on and off for years, and have never heard of this until now. How many of you use this method? http://www.desertsharpshooters...nuals/incredload.pdf I live in C.A. and hunt in the no- lead zone. I have been working on a load for my Rem. 700 7MM with the barnes LRX 145gr.. After lots of rounds I have not found a tight enough group yet. I think I will try this method, I was just wondering how many of you do this and did it work for you?

This is also referred to as Audette's Ladder. I don't have a target frame at 200 or 300 yds at my disposal so I have never used this method, but my S-I-L used this way to find a load for his 257WBY that is kind of a problem child to find an accurate load and it worked very well. Audette's method will not work shooting at 100 yds. I hear of a lot of handloaders using this method when they have the place to use it.

And don't forget the one thing not mentioned...your individual rifle may not like the bullet you have chosen at all and may still provide unacceptable results, given your criteria (whatever that is). You would be advised to try a secondary bullet (or whatever component) as well as just one.

Hey TJB

The only thing I have been able to prove WITHOUT A DOUBT by doing the Audette is that an increase in powder charge will result in an increase in velocity which will exhibit a progressively higher POI on the target. Some "groups" seem to appear but shooting at 300 yards there are other factors which contribute to POI's.

The best example of Audettes is one I did on a 6.5 rem mag (custom rebarrel with 26" Douglas) where I wanted to find the best load with a 130 gr Scirrocco II and RL17. Not having any load data at the time for RL17 I started low and worked up





Now an imaginative reloader could find several "groups" in there but my main purpose was to find the velocity I wanted while at the same time checking for pressure signs. I did not find any pressure signs even at the heaviest loads so I chose the highest velocity at the stiffest charge for shot group #7, 8, 9 & 10 on the last target and chose 54.5 gr RL17

BUT for me that is only 1/2 the test and then I will do a seating depth variation test based on the load chosen while keeping an eye on SD (standard deviation), ES (extreme spread) and group size



So I load 130 gr Scirrocco II's with 54.5 gr RL17 at .060" off the lands for a velocity just under 3200 fps and the strive for consistency in reloading (shoulder position, annealing, bullet grip, seating depth, etc. etc. etc.) and it works for me.

YMMV

An excellent example of load development process
Kudos.

The take home messages from the audette ladder being that YOUR barrel is insensitive to velocity variation in the 3200-3230 fps range.
ie
an ES of 30fps or so around the midpoint of the load at 3215 or so.( from the audette ladder series).

when then shot for group at this load assessing seating depth all but one of the groups is more than acceptable for a hunting rifle at 200yds.
( your rifle did not like the harmonics at .045 off, much at all and was happiest at .060, and even more)

having experienced the classical velocity drop with increasing seating depth you are now outside the velocity window of 3200???- 3230 indicated by the audette ladder .
.......... while 3176 & .060 off is a fine 200yd group .........IF you were chasing group improvement would you consider increasing the load into the midpoint of the chosen audette node at 3215 or so to see effect or stay right where you are , ignoring what the audette ladder said to you (yes I did read your opening comment about audette ladders...... He He)

Whats also interesting is the sudden shift at .090 to an abnormally high SD for the ES range indicating that its not a normal distribution of velocity in those 5 rounds.
Do you conclude anything from that

Your right, I did consider moving up to 55 gr RL17 at .060" off to raise velocity back up to 3200 fps, just haven't got around to it yet. It would be interesting to see if the load at .060" off kept it's characteristic very low ES & SD when velocity was bumped.

The ES at .090" off was taken from these 4 velocities: 3159, 3122, 3174, 3167. If I threw out the 3122 it would be a lot tighter but then again that was part of the data and should be considered.

What was most interesting was the variance of the ES & SD where it decreased progressively to the lowest for each at .060" and then progressively increase again on the higher velocity side. I suspect it would look much like this graph if I were smart enough to plot it, draw it and then be able to post it


IMAGINE VELOCITY PLOTTED ON BOTTOM LINE AND ES OR SD PLOTTED ON VERTICAL LINE

Kudos for noticing, most don't

That's what I was thinking woods, I'm thinking about IMR 4831 then picking the best load, then messing with the seating depth. Than HOPEFULLY getting a very tight group. I thought that by doing the ladder test that you should have at least 2,3 or 4 shots in a group that would be closer than the rest. Then you pick the middle of that group and you should be good to go. Do you think that 200 yards might be a little easier holding on target and getting truer shots? Good 200 yard group by the way!!

quote:

Originally posted by TJB:
Do you think that 200 yards might be a little easier holding on target and getting truer shots?

200 yards will work for some calibers that have a (for lack of a better description) "rainbow" trajectory. That would allow separation between the shots with the change in velocity. 30-30 comes to mind as do some others like 30-06, 338-06 etc with the heavier bullets. With a flat shooter then there would be too many too close to discern any trends.

300 yards is about perfect but for some calibers longer ranges would be even better. 300 RUM with 165 gr bullets come to mind there. I have one buddy that has done them at 500 yards and more but wind becomes a factor as does the just plain difficulty of shooting well at those distances.

The trick is to keep track of the exact position of each shot in sequence. A spotting scope or very good rifle scope is a necessity. Or a target such as I use that allows you to see the POI better.

The thing that will really bust your bubble is to take your whoopee loads back to the range trip after trip an watch the results vary all over.

Well thanks for all the info, I will do the test at 300 and wait for a calm day. I made 15 rounds from 55.0 to 60, and wet buy .3. I also made 4 extra in the middle of those to make sure I'm on target. Should I clean my gun before I go out and let those 4 extra's be my fouling shots to.
Thanks

quote:

Originally posted by SR4759:
The thing that will really bust your bubble is to take your whoopee loads back to the range trip after trip an watch the results vary all over.

this is true
there is more than powder load that creates shot variance.

BUT
so long as the environmental conditions are keeping you within the insensitive velocity window .............things would be worse if you were outside that window from causes other than powder load.

consistency in every component minimises ES , SD & group size .
for a hunting rifle .........so long as that series of groups has a cumulative overlay group size less than minute of vitals ( referencing the aiming point)........relative to the animal in the sights.........its a killing machine.

Woods;
wash my mouth out with soap should you think I inferred culling a data point that did not suit your desires..........He He.

I could only assume from the SD relative to the ES (in the .090 seating depth group ) that you had a distinctly bifurcated range of velocity results, ie 2 different bands of velocity within the group..........yet the
target grouping was randomly spread.
Dropping to 3122fps is the equivalent to nearly 2 grains of powder & the shot fall is not representative of vertical dispersion for such a velocity change.

The question posed in the broadest terms was about data interrogation ( not culling) & what you might conclude from a target group that was at odds with your indicated velocity ES & SD.

Your provision of the actual shot by shot velocities makes that question even more intriguing.
ie was the particular round shot really that different to the others in that group or was it a vagiary of the velocity measurement on that particular shot ?????

Hey Denis, who knows?

Good of you to look and wonder and ask questions. It makes me think and that is always good (although it hurts a little)

The other shot groups

.015" - 3197, 3205, 3228, 3205, 3212
.030" - 3197, 3197, 3189, 3197, 3220
.045" - 3189, 3197, 3182, 3174
.060" - 3174, 3174, 3174, 3182
.075" - 3155, 3174, 3182, 3167
.090" - 3159, 3122, 3174, 3167

It may be the chronograph since it seems it has a predilection for certain numbers like 3174, 3197 and a couple of 3122's

Since the test I have been shooting just a few shots each time at the longer ranges so haven't set up the chrono again

But I haven't found a better method of quickly getting to a workable load with a new gun, powder or bullet

The velocity outrider in the .090 group alone leads to questions about the chrony.

The repetitiveness of some of the numbers leads to more of the same concerns.........alternatively you can take them as verbatim & a pat on the back about your load prep.
If you take the latter.........the 3122 in the .090 group just poses some tougher questions.

Might be time to see if you can back up its data output with another chrony for variations in comparable loads & groups....if you can borrow one.

its all just data, about what you are doing & the most important data is the repetitiveness of the group & the trend between load velocity & individual shotfall.

shooting tho is one of the few places where 2 wrongs can make a right in a group.

Check out the Dan Newberry Optimal Charge Weight on the web. It is a variation on the Audette system, and a significant improvement in the eyes of many.