am I wasting my time doing a ladder at 150 yards?

[scudzuki]

I want to run some ladders with my newly rebarreled (.260 Remington) bolt gun.
I am waiting for my membership at a club that has 400 yard ranges, but it could take 6 weeks or more for that to come through.
In the meantime, the longest range at my local club is 150 yards.
Is it a total waste of time for me to run a ladder at 150 yards?
Will the steps in the ladder at that range be too close together to interpret?

Joe

 

[seanh]

Will the be too close to interpret...possibly, you'll have to be on your game, weather will have to be in your favor etc. I think it can be done but honestly believe you're better off waiting.

if it's only 6 weeks, I'd wait and just have some plinking fun at 150. My loads wold be about 80% of max off the lands by about .050...possibly factory.

 

[scudzuki]

Thanks, I guess I'll just throw together some rounds with 42 gr H4350 and get some trigger time.

Joe

 

[George63]

150 yds is enough for old fashion load development - load 5 each varying up and down from your best guess by .2 grs - pick your best group and go with it - 90% of the time this will give the same results as ladder / OCW testing

 

[melloyello]

Just do OCW testing with 3 shot groups. Find the center of the node and play with your seating depth.

 

[M1Amen]

I second the OCW test method. I did a bunch of ladder tests early on in trying to work up a good charge and all I got was shit results. I was also doing it at 300 yards. After consulting one of the club bench rest champions, I decided to do the OCW method, which calls for 3 shots. I also did it at 100 yards to minimize any effects of wind, and rather than only doing 3 shots, I loaded six for each charge weight. That way, I would have more statistical data and I would have an extra round in case one were a flyer (shooter error). Now I am getting 1/2 MOA out of my gas gun.

Here is what I found: The ladder test method sucked for me. Think about it. If you are shooting a load that produces a 2 minute group, you have no idea where that particular bullet is going to land within the 2 minute radius of that load. So a single shot at a particular load is not a good indicator. Also, you will not get a vertical string by only varying the powder charge because the harmonics of a barrel do not just go up and down. The harmonics of a barrel oscillate in the x and y planes, like a big circle. This is why firing multiple shots from the same powder charge is beneficial. Each charge gets its own target, and each target gets several shots. This gives you a true indication of the dispersion of a certain load.

Then after doing the OCW test, take the best group and then work up a new test to experiment with seating depth. Each seating depth gets its own target and each target gets several rounds. Once you have it nicely worked up at 100, then take it out farther if you want to continue fine tuning the load.

 

[diderr]

I'll be doing mine at 400 when my build is finished, but I've done 100 in the past.