Incremental Load Development Method - Ladder Test

[scalce]

I posted this over ar AR15.Com but I thought some of you might be interested in it.

Here is my thread over there:

AR15.COM :: Forums :: Incremental Load Development Method

Here are some links to articles about this method:

http://www.washtenawsportsmansclub.o...incredload.pdf

Barrel Vibrations, Ladder Test to develop Loads

Bravenet Web Services

Here are my results from my first go at it:

Bullets - 55 FMJ BT bulk and not weighed
Brass - LC fired multiple times and trimmed to 1.74 and rezied with RCBS X-Die
Powders - RE7 and H335
Primer - WSR for the RE7 and CCI 450 for the H335
Press - Dillon 650 (resized, primed, seated bullets, and crimp with FCD
Range - 100 yards with occiasional left to right wind
Charges were weighed individually on an RCBS 1500 didgital scale
Barrel - 24" DPMS fluted SS 1:8 twist

Round # H335 RE7
1 23.1 18.6
2 23.2 18.7
3 23.3 18.8
4 23.4 18.9
5 23.5 19
6 23.6 19.1
7 23.7 19.2
8 23.8 19.3
9 23.9 19.4
10 24 19.5
11 24.1 19.6
12 24.2 19.7
13 24.3 19.8
14 24.4 19.9
15 24.5 20
16 24.6 20.1
17 24.7 20.2
18 24.8 20.3
19 24.9 20.4
20 25 20.5

RE7 Target


H335 Target

[lbreevesii]

interesting! I think that as soon as I buy another lb of varget i'm going to try this. I generally shoot 168 sierra match kings from my 700 SPS Tactical(20" 1:12 twist).

Does anybody have a really good method of determining the best OAL for a rifle? Any input there would be appreciated.

~Larry

[fredj338]

The problem w/ the ladder method is you can;t really do it at 100yds. You really need to be 200yds, 300yds is even better. The shot to shot variation just doesn't show up enough at 100yds. Unless you have a very good spotting scope, you'll be spending alot of time going back & forth @ 300yds to check each shot. Another way to do it @ 300yds would be put up 10 separate targets & fire one shot each then overlay all the targets. Also a 1/10gr diff. in powder charge isn't enough w/ most cartridges/powders. I load in 2/10gr increments upto the max. charge.

[fredj338]

Originally Posted by lbreevesii

interesting! I think that as soon as I buy another lb of varget i'm going to try this. I generally shoot 168 sierra match kings from my 700 SPS Tactical(20" 1:12 twist).

Does anybody have a really good method of determining the best OAL for a rifle? Any input there would be appreciated.

~Larry

OAL for a 308 round? I use magazine length first. Then check distance to lands. If I am off the lands w/ the bullet seated out as far as I can get to feed through the magazine, that is the length I use.

[Hank Ellis]

I use this method. Also called the Audette method. It works. My first try at it with AA2015 and Hornady 52 A-Max out of a Clark Gator gave me sub-MOA at 100yd.

Originally Posted by fredj338

The problem w/ the ladder method is you can;t really do it at 100yds. You really need to be 200yds, 300yds is even better. The shot to shot variation just doesn't show up enough at 100yds.

Knowing what I saw at 200yd, I wouldn't even bother at 100yd. At 200 you really see what the load is doing.

Unless you have a very good spotting scope, you'll be spending alot of time going back & forth @ 300yds to check each shot.

I set up a camcorder a few feet uprange from the target and film each hit. When I get home I replay it and mark each hit. Saves a bunch of time.

Also a 1/10gr diff. in powder charge isn't enough w/ most cartridges/powders. I load in 2/10gr increments upto the max. charge.

For .223 use .2gr increments. For .308 and similiar cartridges, increment .3gr.

[scalce]

Yeah all of the articles state that 200-300 yards is optimal.

Is this even useful with lighter bulk bullets that can range +- .2 grains?

It would be really funny if I buy a camcorder just so I can do this test correctly.

Maybe I convince the wife that we can use it to analyze golf swings too.

Thanks for the posts.