Range Report Ladder test, just curious what others would pick

[jonaddis84]

Ran a ladder on my 20" 6.5cm today at 400yd. 0.2 increments of IMR4350 from 43-45gn, 130 Berger Match VLD 0.010" off (as long as I could fit in mag). I like #8 & 9 for a node, and their velocities are damn close on the two tests. The two tests are identical loadings, just wanted to run two incase I screwed one up, and was curious how much they would match up.
A little disappointed in their lack of similarities, but part of that could be me, thats what makes these things so tough to judge.

 

[J-ROD]

i never liked ladder testing, dont flame but it never gave me much info or made sense to me when i tried, other than upper pressure limit at that OAL. my load testing groups go from extreme vertical to nice little groups that are almost easy to shoot or forgiving if that makes sense. When doing a ladder, i never knew which of those rounds was a high shot or low shot.
i have found that my barrel has nodes around 2660, 2810 and 2960 (three that i use the most) so i aim for those with my charges and shoot groups in increments below and above, provided they are safe. i then fine tune, aiming fornthe middle of the node to account for temperature of powder, charge wt, neck tension & oal variances.

if that were my gun, i would start off shooting at least 5 shot groups in .5gn increments at and below max safe charge weight, ~ 4 to 5 sets of 5 rounds.

I also abandoned round robin as changing my position up for each bull messed me up. i just shoot 5 like i'm in a match, then get up and stand for a few minutes, then go to the next set.

 

[Bigwheels]

What were the conditions during the two tests? Was there wind? How were you positioned? I use ladder tests followed by round robin to get my loads, but every shot must be taken with utmost care to provide valid info. I also don't bother with a chrony during load testing. I do that after I get the groupings I'm looking for, during my zero, & range verification.

 

[17874]

I always run three rounds at each load in three separate strings. I also run a target cam to sort out the info. I bring the target home, watch the video, mark the hits and make my decision. Example of shooting order. With three shots at each load, it tells you a lot.

1- 43
2- 43.5
3- 44
4- 44.5
5- 45

10 minute cool down

6- 45
7- 44.5
8- 44
9- 43.5
10- 43

10 min cool down

11- 43
12- 43.5
13- 44
14- 44.5
15- 45

 

[jonaddis84]

Not much wind to speak of.

Shot off bench with Atlas and rear bag.

I'm not a benchrest shooter so I can't say some of it wasn't me, but I felt pretty confident. #3 definitely could have been pulled on first test. #7 chambered hard, must not have fl sized it somehow so that could explain the strange velocity and impact.

My wife was spotting impacts on the razor spotter and drawing them out, after reviewing backup video footage, #1 and #4 on first test are swapped (doesn't really affect much).

I think looking at these close ups is deceiving. Keep in mind the group of 8,9,10,11 are a 1"group at 400yds, to me (along with the velocity numbers of 8 and 9) that is a pretty Damn good node.

What bothers me is that it didn't happen again on second test, but that could be shooter error.

Galaxy S3 on tapatalk

 

[jonaddis84]

Also, I could be wrong, but don't you think the velocity numbers speak as much volume as the targets themselves? No other velocities between the two tests are as similar as #8&9 on both tests.

Hell, it's at least a place to start, I'm sure this rifle will shoot anything I put in it well, but I'd like to reduce my es/sd as much as possible. I shot 10 or so rounds just to find my max pressure at 100yd, they all grouped in 3/4" and ranged at least 2 grains in charge.

Galaxy S3 on tapatalk

 

[damoncali]

i never liked ladder testing, dont flame but it never gave me much info or made sense to me when i tried...

That makes two of us. The big issue to me is statistics. A ladder test uses a sample size of 1 which just isn't good enough. If you're going to shoot groups, shoot groups.

 

[VKC]

I would pick #9, load at 0.1gr increments low and high. Then go back to do ladder test and 10-shot groups to confirm.

 

[Bob 964]

On the top photo, it looks like the 4,5,6 node provides the least vertical dispersion, followed by the 9,10,11 node. In the bottom photo, it looks like the 5,6,7 node provides the least vertical dispersion.

 

[jonaddis84]

I ran with 44.4 (which was #8) and loaded up 44.3, 44.4, and 44.5 for testing at 100. 44.4 shot the best with a .296 5 shot group off a bipod.

Loaded up 40 of those and went out to 1000 today, they shot very well, hard to say exactly how well since the mirage was pretty nasty, but they were shooting 1/3 or so on elevation spread as I wasnt shooting for wind, just dialed and held center for each shot.

They were rocking 2915 out of the 20", plugged it into Shooter and the dope was dead nuts out to 1k, didnt have to change anything.

 

[VKC]

Sounds like you are dialed in. Awesome

 

[2clicks]

I like the .5 grain increment too the elevation climb is more visible and so is the "flat" spot accuracy node specially at 600 yards where I do my testing at. The velocity measuring simultaneously is very important too IMHO. Once in a while u can get that odd ball in a string 50-60 fps higher or lower its important to take those variances into consideration. Absolutely love the ladder test!

 

[steve123]

I'd give #5 consideration.

 

[azimutha]

FWIW, .4 gr. increments give a decent spread, lower the number of loads tested (e.g. 6 across a two-grain spread), and for OCD types are tidy (e.g. 43, 43.4, 43.8, 44.2, 44.6, 45). To minimize variation I color-code each load with sharpies, mag-load them in order, and fire all 6 loads. I wait 10 minutes for barrel cool-down between and repeat twice. IMO, you might as well chronograph them too because every round down the pipe costs time, effort, money and causes barrel/throat wear. Might as well make the most of it.