Ladder Testing-load development methods (help!)

[Big_Tex22]

Been reading about the "Creighton incremental load development method" in an article I found on a web search. I guess probably everyone on this site probably does something like this with ladder testing and all, but Im young and just starting to get into this reloading stuff a little more seriously. This method really opened my eyes on building a load, seems like doing this you can choose ONE bullet, primer, and powder you want to use and make it work by only changing the charge, is that right? The article really went in depth on barrel vibrations and the recoil effect, and how velocity and time in barrel matching with the vibration and recoil can be tuned for any bullet, primer and powder to become accurate in a barrel. Stringing 1 round of a .3 gr increments of powder charge with the 20th being max load. Then shot 1-20 in sequence at 200-300 yards so the "ladder" reveals nodes at which vibration and recoil affect begin to cancel out at certain velocities. Again, I feel that this is a common method you all probably practice I guess?

Ive always just gone about testing 3 or so bullets with a mid range powder charge in each. Group 5 shots to find the best bullet. Then with that bullet, try 3 or 4 different powders, again group 5 of each, settle on a power. Then vary the charges of that powder and group, then the primer and group, then the OAL and group. I know, this turns into a marathon!! And when I get done, how do I know I shouldnt have changed tried changing OAL before I changed Primers, or any of it???? I guess Im sounding dumb by now but its not the first time, so I dont mind. I just got my first chrono so I guess I gotten a little more interested and trying to become a little more effective of a reloader, that's when I've stumbled on to this ladder stuff.

My main question when I go to string 20 rounds is the barrel heating up. Do you completly let the barrel cool between each shot? The article didnt mention how barrel heat affects recoil affect and vibration, it just seems to me that this would be a big factor when reading a ladder string and corresponding velocities??? Also I think I might have read one poster on here that when chronographing and stringing shots together at fairly long ranges that you cant see each shot on paper clearly, using a video camera on target to see the holes pop in order? That seems pretty practicle, and using my wifes camera maybe she wouldnt mind me slipping of a sand bag and making camera splinters!!!!

Any input for a rookie about load development methods? And maybe more specifically barrel heat during stringing??
Thanks
Mark

 

[milanuk]

There are a few versions floating around in general circulation these days... There is Creighton Audette's original ladder test, then there is the 'Incremental Load Development Method' from Randolph Constantine which appears to be mostly the same thing, just updated slightly (I think there is an article from Precision Shooting magazine on the subject). Finally, there is the 'Optimal Charge Weight' method by Dan Newberry (goes by 'green788' on a number of forums.

The basic concept of all these methods is the same: finding a 'node' or sweet spot where the the load will be somewhat tolerant of little inconsistencies. The OCW method attempts to address a couple issues, namely barrel heating and fouling that may change between the first shot and the last shot. It almost always takes more loaded rounds to accomplish, but you can often get more useful information from the target @ say, 100yds (if that's all you initially have available) and dial it in further as you need. Also, a lot of people just don't shoot 300yds very well (i.e. well enough to know if one shot goes higher or lower than the last due to the shooter or the load)... I know our ranges here are pretty protected the first 100-150 yards, but by 300yds they are in a jet stream... kind of hard to get good results when your shots are scattered to and fro by the wind!

In the end, any one of these will work as far as getting you closer to a good load. Some amount of final tuning will still be required any which way you go. The video camera method does work, according to others (I always manage to forget to take the dang thing along). Another method that does work reasonably well is to get one of the big 12" Shoot-N-C targets and aim at the center of it (@ 300yds). The bright fluorescent yellow holes against a black background are fairly easy to see under decent conditions w/ even a modest spotting scope (or good rifle scope). Under *good* conditions w/ a good scope, you can often see them @ *600* yards (later testing stages).

FWIW, Dan has a website on his ideas here, and Randolph Constantine hangs out from time to time over on long-range.com (user name 'lostaxe') so you might be able to PM or email him if you want details on his version.

Monte