Ladder test results. ( Help guys please)????

[247sniper]

Hiya guys, can someone help please..

Rifle, .204 Ruger. Reloader 10 and 39 grain SBK's

I have researced the ladder test system to find optimum charge weight etc. I made the loads up, from 21.6 grains( staring load)up to 25.1 grains. in .3 grain increments. ( book max) I knew what I was looking for, but I never got it. shot at the target set up at 200 yards away and apart from aprox 3 inch horizontal spread due to strong blustery cross wind, there was only 1 inch Max vertical despurtion between the two furthest holes, ( Them shots being number 3 and 5. The other 11 shots were all almost the same level in hight, if it wasnt for the wind ( horizontal spread), they would probaly be toutching. How can this be with approx 3 full grains between min and max load, Was expecting to see some sort off vertical dispertion and some sort of cluster formation

What would be the next part of load development guys as I am really confused now


Thanks guys

Steve.

[Wrangler John]

In my long and varied experience I never used the ladder test mumbo jumbo - I believe it isn't statistically accurate enough for my purposes. With Reloader-10x the majority of loads will print between .5" and 1.0" at 100 yards. This makes the ladder difficult to use even at 200 yards, probably because of the .204 Ruger cartridge's efficiency and inherent accuracy.

What you are describing is, as you noted, due to environmental variables - wind. Ballistic testing in variable outdoor conditions is sometimes ambiguous, which is why anything other than a still day is stacking the deck against a meaningful result. Increase the range to 200 yards and the environmental error doubles or more depending on downrange conditions not perceived by the shooter. The gun club where I shoot has 100 and 200 yard ranges, both are subject to swirling winds where wind flags placed ahead of the muzzle, at mid-range and within 10 yards of the target can all point in different directions and with different speeds. Shooting for groups requires I wait for a still morning with light breezes barely able to lift a surveyor's tape streamer, preferably also accompanied by low overcast or light fog (both require light winds at ground level). The only other alternative is a ballistic tunnel.

Good news is that even with the variation in powder charges all your shots were so close as to be quite exciting accuracy even with the wind.

What I do is load 10 rounds of each load, and a few extra of the starting load for fouling shots. At 100 yards, after swabbing the barrel clean with alcohol and lubing it with graphite or moly cream, three foulers are fired. Then ten shot groups are fired over the chronograph making note of wind conditions for each shot. If I get a flier and the velocity E.S. is within the average for the load, it's either me or the wind. If the E.S. is something out of range, then I suspect that particular cartridge and/or the wind or me. Also in the .204 Ruger, I have found that using Rl-10x with most bullets the accuracy load is usually near the starting load. After finding an accurate load, the best accuracy reveals itself with seating depth changes, in most cases near the factory depth. In my rifles, 25.2 grains of Rl-10x with the 26 grain Varmint Grenade seated at 2.260" or well off the lands. This load develops around 4,110 fps and kills like a laser out to 250 yards, consistently shooting .250" groups at 100 yards.

All this alchemical stuff is as much fun (or frustration) as the hunting.

[Hedge]

Like WJ says, shooting at 200 yds has too many variables that will affect the reliability of the test. That's why I quit using it and switched to the OCW method. You shoot it at 100 yds with a series of 3 rounds of each powder load. Usually 5 - 7 loads.
Shoot the loads round-robbin (1 rd of each load at a different target for 3 strings). Fixed time between shots for barrel cool-down.

The results should show 3 consecutive groups where the center of the each group has nearly the same POI. The middle group will be your Optimal Charge Weight. From there you tighten the group size by bullet seating.

[Jim White]

I've tried both systems and of the two I prefer the OCW using the round-robin method. I'll also retest any preceived "good" load on another day just to make sure it wasn't a fluke. In the end, especially with target rigs, I'll shoot a couple of 22-shot strings w/o cleaning to see how it tracks.

[247sniper]

Thanks for your help guys,

Here is a photo of the results, so you know and understand better on what I mean. Im shocked that at 200 yards, with 3.5 grain powder differances between bottom and top load, there apperars to be hardly no vertical spread, only horizontal, due to strong full on cross winds. I am hoping that this is going to be promising though.

Im going to knock some loads up and shoot some groups and check for some concistent MV's over the chrono. And see how I get on chaps.

Heres the picture...what do you thing]k?

http://i1090.photobucket.com/albums/i37 ... est002.jpg


Steve.

[bow shot]

Just my .2c...

1) Keep in mind that in the ladder test, your barrel's oscillation may not necessarily be up/down, it can be right-left, figure 8, circular, etc., so don't put all your eggs in one basket (ie., the ladder test) unless the results are very plain (ie., they don't generate more questins than answers)

2) It reall, really helps to refrain form the test untill you have ideal no wind or dang close to it.

3) If you keep up with the ladder, shoot it 3x, round robin... you may be surprised at the result.

4) Make sure your recoil control (read that, "form") is consistent!! or you will confuse the effect of your load variations with your form variations

[DoubleUp]

Like others have said, I prefer the OCW method at 100 yds. I have shot some ladders with the 204 but range was 350 yds and vertical dispersion was easier to see at that range. Always tried to have a very calm day for a ladder test, but not easy where I live.