help with ladder test results

[The_Hoff]

Ok, I redid my ladder test for my precision AR rig in .223

I will be loading to mag length.

my rifle has a NATO 5.56x45 chamber so it can handle higher pressures than a standard .223 barrel. It is a true 1:8 twist 24" Heavy Bull barrel, target crown

My rifle is a 1/2 MOA rifle on a good day if i do my part so that variable is out, also target was shot using a rear bag

I am using varget because of its intemperace to temperature which is good down here in louisiana lol.

MY load: LC .223 brass (headstamp LC 94)
Win small rifle primers
sierra match king 77grain HPBT
Hodgdon varget

brass trimmed to 1.750" +/- .001"

brass chamfered, deburred, primer crimps reamed, and primer pockets uniformed.

brass is FL sized and primed with lee hand primer

each charge is thrown weighed and trickled to exact amount.

bullet seated to an OAL of 2.255 +/- .003" for meplat variations

for now i am using lee dies, about to upgrade to a high quality competition die set with micrometer seating die

I loaded 5 rounds of each charge, going in .2grain increments

23.0
23.2
23.4
23.6
23.8
24.0
24.2
24.4

(NO PRESSURE SIGNS ON ANY LOADS!!)

for testing I placed my target at 300 yards and dialed 1.2mils of elevation

wind was about 3-4 mph from my 9 o'clock but i did not adjust, hence the drift on my target. temp: 65*F. sun was beginning to set at my 2 o'clock.

My firing routine proceeded as follows:

1. fir two shots of same load.
2. 2 minute break while i go and mark target (barrel cooling)
3. repeat for all loads

I am having a hard time interpreting my target and fining the nodes any ideas? I have a match this weekend and have to have a solid load by tomorrow night lol. "burning the candle at both ends"

 

[The_Hoff]

Re: help with ladder test results

anyone?

 

[thefitter]

Re: help with ladder test results

I'm only seeing 2 rounds for each load?

It's my understanding that a ladder is to find the load that holds vertical. Therefore I would pick 24.4 and work on the wind reading.

 

[The_Hoff]

Re: help with ladder test results

yes i took 2 shots with each load, the other 3 rounds of each charge is for retesting certain loads

 

[Alan Griffith]

Re: help with ladder test results

Hoff,

Definately focus in around 24.2 and 24.4

 

[tullius]

Re: help with ladder test results

1. Reread TresMon's ladder testing sticky, then read it once more. I'm not sure you're understanding it yet.

2. Start @ 23.0 and go to at least 26.0 in max 0.5 increments.

3. Load only 2 rounds of each charge weight.

4. Separate rounds into 2 identical test groups.

5. Color both bullets of each charge weight a different color from the other charge weights with permanent Sharpie. Color the whole bullet: this color will be imparted to the paper when the bullet passes through. I find it advantageous to use several layers of white blueprints for target paper.

6. Write charge weight of round on side of brass case, using the corresponding color. Mark charge weights over book max. so you can pay close attention to these cases when you're firing.

7. Make a chart of what charge each color signifies off to the side of a target with two bullseyes, large enough and with enough space to ensure all shots will be on paper and the two tests won't overlap.

8. Put target out @ 300 yds.

9. Run through ladder test twice, progressing consecutively from low charge to high charge, twice, first at one bullseye and then at the other. WATCH THE BRASS CAREFULLY AS YOU'RE SHOOTING. Stop testing when you see signs of excess pressure. Record the max load for your rifle.

10. Retrieve target, mark each hole with the appropriate charge weight. Use a q-tip soaked in rubbing alcohol and run it through the hole if you can't make out the color on the paper, or if the bullet has struck the bullseye: the color will come off on the q-tip.

11. You should now have two identical tests that should show agreement: turn the target sideways to determine the charge weight range(s) that are giving the least vertical displacement. If the tests do not agree, you're not shooting well enough to run the tests: save the target for reference and run the tests again another day.

12. Once you've found the optimal charge range, refine ladder test to reflect isolation of the optimal charge weight range. Run a smaller ladder test to find optimal charge weight within that range.

13. If necessary, keep optimal charge weight constant and run more ladder tests to find optimum OAL. You probably won't need to do this with the platform you're running.

 

[tullius]

Re: help with ladder test results

Here:

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1713419&page=1

 

[The_Hoff]

Re: help with ladder test results

thanks printing it now, to study tomorrow

 

[The_Hoff]

Re: help with ladder test results

going to load up the ammo i need for my match with 24.4gr varget then once match is over do a full load workup following tresmon's plan

 

[vman]

Re: help with ladder test results

Good luck with your next ladder

 

[Casey Simpson]

Re: help with ladder test results

Hoff, you're doing fine. Keep at it.

www.optimalchargeweight.embarqspace.com

 

[Rover31]

Re: help with ladder test results

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Casey Simpson</div><div class="ubbcode-body">Hoff, you're doing fine. Keep at it.

www.optimalchargeweight.embarqspace.com </div></div>

the experts here are better at reading the subtle points of your ladder... but what I did for my guns is a combo of the ladder test and the this ocw test above. It works very well!
One day I did a ladder test as you did. It was able to give me a general load/charge weight area to work in. I then loaded up 5rds of the charges I thought would work. Shot them at 300yds and got it dialed! do both don't just rely on the ladder.
T

 

[woodspider]

Re: help with ladder test results

And go longer if you can itl bring out the differences better