Ladder test or OCW method

[Kenny Wasserburger]

My first load test when using Goex or Olde Eynsford is to dip a case in the powder in a bowel and strike off the excess, dump onto the scale the powder from the case, and record that charge’s weight, I do this a total of 10 times. And then take the average weight of these 10 loads. That volume’s average weight is where I set the scale at for my initial load test. This particular method was passed on to me by noted Goex Shooter and former representative, Bill Bagwell Aka Redneck on the various Internet forums, it is pure simple genius. I drop tube 3-5 rounds of that particular weight add my compression wad and compress the charge to the depth my bullet’s overall length requires to chamber with a cartridge seater which engraves about 1/2 to 3/4 of the first driving band into the rifling. You may seat your own bullets deeper in order to chamber easily, especially for silhouette. If so then you must rely on consistent neck tension, which requires at minimum, neck sizing of the case and annealing. I believe the only real consistent neck tension is No neck tension and it works exceptionally well with PP loads. I prefer to slip fit my bullets after, just ever so slight a belling, this for grease groove bullets sized at groove diameter, and not FL size my fire formed brass. A slight bump in the sizing die to remove the bell finishes the process. Then I add half a grain of powder to the next 3-5 cases for testing and so on for 1 to 2 grains of powder. With Swiss I change things up a bit I do the same test of dipping cases but after establishing a average weight I drop that by 1.5 grs weight for my initial weight to test. This is with 1.5 Swiss, as it yields a good bit more energy that the Goex powders.

The ladder Test method, or Optimal Charge Weight.
My dear friend Dan Theodor, insisted for load work up that at least 1/2 grain increments be used with BP. From my personal experience, I would say I could not agree more. Using the above outlined method to determine a starting charge, I then increase by 1/2 grain for each following load test. This also means that the compression is increased with each increase in charge weight. I determined a overall cartridge length that will have my bullet’s first driving band engraved into the rifling at .020 or more. This ensures a consistent start pressure, which helps with constant chronograph results. This is of course for grease groove bullets and not for paper patch bullets. This is easy to do with slip fitted bullets, simply fill the case with your charge add a wad and compress the charge, short of what you will need, place an unlubed bullet in the case, (less mess) check to see if the cartridge will chamber, it shouldn’t. Remove the cartridge, you may have to tap the bullet out of the barrel with a rod. Now increase the compression a couple turns of the die or the stem, if the case is far from chambering. If it’s close, only increase the compression in small 1/4 turns of the compression stem or the die. Once you reach a point where the cartridge all but chambers you are at the depth your compression stem and die needs set and now locked for this particular bullet. If you prefer to have your ammo chamber without any thumb pressure or without the aid of a cartridge seater tool. Just increase the compression depth till the cartridge seats in the chamber and the action closes without any aid. Your optimum compression depth has thus been determined, remember that if you use multiple wads you will have adjust the depth for this. The amount of compression will be determined by the amount of powder used.

My loading test method entails loading 3-5 rounds with the same charge, and then 3 more of the next incremental weight, and so on. Test Distance is 200 yards I set up 4 targets on the backer. I fire one shot at target #1 for load #1. Load #2 one shot at target #2. And so forth till one shot of each load is on each corresponding target. I then repeat the process, till all 4 targets have 3 shots on them. I try very hard to shoot each shot in the nearly same condition. I plot each shot for each target, if I pull one I note that and discard that shot from the results. This is important, so you can keep track of any changes. There is no rush, so do not hurry, I have taken up to one hour to shoot just 12 shots. This is why I load 3 rounds for each test target. Fouling control is the exact same as if I were shooting an actual match. I prefer this to the ladder tests I used to use, originally brought forth by noted shooter and engineer Creighton Audette. The OCW test (optimal charge weight) is similar to the ladder test. But it is easier with multiple targets to identify and track noticeable nodes of accuracy, where as one can get easily lost in tracking one’s shots on the ladder test. Both take a similar amount of time to preform. Tracking 3-5 shots per target is easier for me at least. The OCW method is credited to the shooter Dan Newberry. He has a website. The method lends itself well to the BPTR shooter for load development in my opinion.

Kenny Wasserburger

[Lumpy Grits]

This writeup should be 'pinned' to the top of this page!
Gary

[Kenny Wasserburger]

That is an excerpt from my up doing book on BPTR.

Kenny

[gus65]

Kenny, when will your book be available?

[Kenny Wasserburger]

Mid summer I hope.

Kenny Wasserburger

[mdeland]

Good stuff Wasserburger, makes sense!

[Lumpy Grits]

Let us know when the book comes out
Gary

[SSShooter]

In Kenny's info above he is talking about cartridge OAL (overall length) in his 2nd paragraph.
Hornaday offers a tool https://www.hornady.com/modified-cases#!/ for finding the OAL with a modified case (primer picket drilled out and tapped) and a bullet without any lube or wad or powder, etc., involved. Hornady offers the modified case in 45-70, so easy enough to size it down to 40-65. If you have another cartridge for which they do no offer a case they will drill yours if you send one to them. The last time I did so (for my 38-55 & 38-50) it was $17, total for them to drill & tap the case to fit their OAL gauge, including return shipping. I used as a starting point for my F-Class rifles and was simple enough to use with BP rifles.

[bruce m]

hey kenny.
1 book from you will be better than 10 books from matthews.
bruce.

[cpt.creedmoor]

In Kenny's info above he is talking about cartridge OAL (overall length) in his 2nd paragraph.
Hornaday offers a tool https://www.hornady.com/modified-cases#!/ for finding the OAL with a modified case (primer picket drilled out and tapped) and a bullet without any lube or wad or powder, etc., involved. Hornady offers the modified case in 45-70, so easy enough to size it down to 40-65. If you have another cartridge for which they do no offer a case they will drill yours if you send one to them. The last time I did so (for my 38-55 & 38-50) it was $17, total for them to drill & tap the case to fit their OAL gauge, including return shipping. I used as a starting point for my F-Class rifles and was simple enough to use with BP rifles.

thats what i use for my f-class and bpcr stuff...i make my own cases...get you a 7.3mm drill and a 5/16-36 right hand tap and let her rip

[sackett]

Is that the old Stony Creek tool from the 1990's with just with a new name/maker?

[SSShooter]

Is that the old Stony Creek tool from the 1990's with just with a new name/maker?

Yes. Hornady bought Stony Creek some years ago.