Ladder Test how-to

[7mmfan]

I'm heading out this weekend to do some shooting. I'm trying a new load for one of my rifles and want to work up a ladder test this time. Never really done a true "ladder test" so I'm curious what your protocol is.

Do you load one round in increments from min to max and look for the plateau somewhere in there, or are you shooting groups and doing the same? The gun gets hot fast, so if I try to shoot more than 12-15 rounds it will take all friggin day.

We will have a chrono on hand to monitor velocity as well. Plan on shooting as long of distance as is feasible, 250-300 yards.

[jasnt]

For a first timer on ladder test I’d recommend 2 shots at each charge weight while recording speed.  Write down speeds as they are recorded. Can be a pain remembering everything later on back in the reloading bench. 

[Magnum_Willys]

You are looking for groups with similar elevations.   Even with a . 5 moa rifle less than 3 shot groups are tough to interpret though you can shoot one shot groups just go up smaller increments .   6 shots at .2 grains apart or two groups of 3 at .6 grains apart. 

Log speed of each shot.

Get a barrel cooler!!!

Shot this at 500 yd two days ago   

[7mmfan]

I was planning 1 shot per charge in .2 gr increments just to try and ID a plateau of similar velocities, and then load 4-5 shot groups to test within the ranges of that plateau for the next trip out. Is that overthinking it? I don't get enough time to fiddle around a whole bunch with my loads so I'm trying to streamline as best I can.

[Magnum_Willys]

https://www.amazon.com/dp/B01M0FWO69/ref=cm_sw_em_r_mt_awdb_hnq6Eb46HST33

Barrelcool   , could get acquarium pump too   

[Magnum_Willys]

Sounds like a good plan   

[birddogdad]

Google Scott Satterlee videos on this..

[Jonathan_S]

I don't even think I'd use a chrono for loads that would only be shot at 250-300 yards.

Zero at 200, Up maybe MOA at 300?

[Mtnwalker]

I don't even think I'd use a chrono for loads that would only be shot at 250-300 yards.

Zero at 200, Up maybe MOA at 300?

Guessing he meant shooting his ladder at 250-300, not max hunting range..?

[Crunchy]

I thought ladders were supposed to be shot at 400 min?  That was you get an accurate vertical spread. 

[7mmfan]

Planning in doing the ladder test at 300ish. 400 would be a tough nut around here. I see 400ish being my max hunting range with this round, 7mm-08, 140 gr Accubonds. Dont even know if they'll shoot, nothing else seems to at this point, but I keep trying.

[TooTallMike]

Longer distance the better. However I recently did a load work up using the satterlee method at 130 yds and it worked great.. saved a lot of components

[Jonathan_S]

I don't even think I'd use a chrono for loads that would only be shot at 250-300 yards.

Zero at 200, Up maybe MOA at 300?

Guessing he meant shooting his ladder at 250-300, not max hunting range..?

Gotcha, I guess I read it too quick.

[bullfisher]

At that range you'd be better off with an optimum charge weight test (OCW). 3-5 shots, pick your most accurate and either refine it with tighter weight variance OCW test, or go straight to a seating depth test. A 300yd ladder test might just confuse you, cause it did me. At 600yds a ladder test starts to separate and clear up for me. Like mentioned above, the further the better for ladder tests.

[Stein]

At that range you'd be better off with an optimum charge weight test (OCW). 3-5 shots, pick your most accurate and either refine it with tighter weight variance OCW test, or go straight to a seating depth test. A 300yd ladder test might just confuse you, cause it did me. At 600yds a ladder test starts to separate and clear up for me. Like mentioned above, the further the better for ladder tests.

 

The problem with the ladder test is you are usually only using one shot at each load and the shot is subject to both your accuracy as a shooter and the rifle's.  Say you are shooting .75 MOA, you don't know if that hole is the center of the pattern or on one of the edges and each hole in the paper has this same issue.  Interpreting that is a big problem unless you really space them out by shooting long.

I had good success with shooting 5 shot groups at different charges and finding the tightest pattern and then coming back with 5 shot groups a bit above and below to see where it's best.

I also have success using a chrono and picking a few loads with low SD and then looking at groups to confirm.  That helped a bunch as it removed the shooter, wind and other variables.