Finished my ladder test, now what?

[thomashoward]

I find my powder load via ladder. Depth I start with jam and back off .005 with 4-5 different depths. It will be revealed to you

[olddav]

Finally got around to trying the second half of load development. I loaded a total of 15 rounds (5 sets of 3), started with a COL of 3.258", followed by, 3.245", 3.235", 3.225", and finished with 3.215". Shot each set at 200 yards with bags supporting the rifle both front and back and I let the barrel cool between sets. The best group was produced by the bullets seated futherest from the lands, sub MOA (1 5/8"). It might produce a tighter group but I had some hortizional stringing.

I think if I need to develop a load again I'm going to use the ladder test. Two sessions and I'm done, close enough for a hunting rifle.

[limige]

I tried a ladder at 300 yrds and it was worthless. 500 is really the ticket. I just need to find a place near where I moved to shoot 500.

If your limited on distance I would really try the ocw method.

At 200 yrds grouping issues mess up the test. Unless you can shoot it 3-5 times and come up with the same nodes.

But yes seating test would be next in two nodes and find which one comes out on top

[tufrthnails]

Okay you guys are saying 100 and 200 yards are not correct for a ladder test and that 500 is the intended range for a ladder, but why is 500 the intended range. This is just me thinking and talking/typing but 500 yards gives a whole lot more time for things like wind no matter how slight to effect groups. #2 500 yards is a hell of a distance for someone looking for an accurate hunting load although some regularly hunt at that distance out west and such sub 200 yards shots are probably more the norm and where i would want my accuracy. So educate this shooter trust me it wouldn't be the first time a discussion on this forum changed my mind on a topic!

[JTCrl]

Ladder tests can be done at any range. Longer ranges may make identifying the nodes easier but, as mentioned above, must be done under "perfect" conditions to be valid. If you can get those conditions then doing your ladder tests at the range you do most of your shooting at makes the most sense. Even at 200 yards a "light and variable" wind can compromise your results.

I have heard veteran benchrest shooters say they minimize the vertical component in their groups via the ladder test then minimize the horizontal component with seating depth. Never found it to be quite that simple myself but, once you have established a seating depth your rifle likes, you have a better starting point for your next ladder test. And the next, and the next, and on it goes.

Yes, you do need to start over with a new ladder test every time you change a component. A 52gn Berger may not like the same recipe as a 52gn Barts in the same rifle. When switching from a Winchester primer to a Remington primer I've found I need a 1% increase in the powder charge to achieve the same velocity though not necessarily the same results. Lake City brass has a slightly greater case capacity than Lapua brass.

I have not found seating depth to be a very valuable tool when trying to shrink 1 1/2" groups to 1" in a hunting rifle, more valuable when trying to shrink .3" groups to .2" groups in a target rifle. Of course target rifles have the advantage of not being limited by magazine length or the need to seat bullets deep enough in the case neck to keep them secure under hunting conditions.

Just my personal experience, your mileage may vary:usa2:

[FW Conch]

It's because 100 or 200yds is not enough distance to open up the groups enough to see a definite difference in the nodes. 300yds will work for a ladder test, but like the guys that can shoot 500yds are telling you, it's a lot easier to see the differences at that distance.

[tufrthnails]

Okay I am tracking I was thinking there was something at 500 yards that rounds would do differently then at 100/200. Basically it is just easier to see the difference in .5 MOA and 1 MOA at 500 yards then it is at 100 yards. My new way of doing my ladders now is to load my steps and head down to the 100 yard indoor range I found 45 min away from the house shoot them there and get new nodes for several weapons then head to a range that is an hour and half away after a few trips shooting ladders at the indoor and shoot them at 200 yards although I am looking forward to working that out farther.

[olddav]

Just to add to the decussion, the nodes I found at 200 were pronounced, perhaps it was a fluke. Admitted I am shooting a hunting rifle with a thin barrel and I was only able to achive a sub MOA group at 200 yards with two trips to the range, good enough for hunting. If I was shooting a target rifle (capable of one ragged hole) I would suspect that at 200 yards I would experience a whiteout if you will, (too many holes in too small an area) and would need 500 yards to separate the shots.

[JTCrl]

When I shoot a ladder I load a series of 12 loads, 2 rounds of each load. For a 223 loads are generally in .2gn increments. You can use whatever number of loads, group sizes, and increments fit your purpose.

The 12 2-shot groups are each fired at an individual target. A group of six targets fits on one 8.5x11" sheet of cardstock.

http://accurateshooter.net/targets/TargetC.pdf

Measure the distance from the bottom of the target to each hole, plot them on a graph, your nodes will appear.

Edit: Apparently I need to figure out how to insert a picture!:rant:

[limige]

You cant do seating first I've tried.

The seating depth will vary with load.

For instance my creedmoor would shoot hole for hole but with extreme fliers kissing the lands at 43.5 gr.
Backed off to 42 and .01 off shot best.

Back down to 41.2 and it was like .03

The lighter the load the more of a running start it needed to engage the rifling and stabilize.

But granted they are all in the same ballpark but still affects short range grouping

[TC260]

You cant do seating first I've tried.

The seating depth will vary with load

In general I haven't had much success starting with seating depth first either with the exception of some Berger 115's in a 25-06. Two ladder tests and an OCW test with this known accurate rifle were disastrous. Called Berger and they clued me in to their 0.040" seating depth test to establish the proper range. At 0.080 off the lands the rifle was back to it's old tack driving self again. From there I did the ladder and then fine tuned depth afterwards like normal so it wasn't completely a matter finding the depth first but getting in the right ballpark before starting on charge was crucial to getting that bullet to work.

[limige]

Good to know! Still trying to perfect a process