Minimum effective range for a ladder test?

[JWEM]

I'm looking to try and work up a new load in .308 with the 190SMK, 178HPBT (Hornady Match) and 208 Amax. All in Lapua brass over Vihtavuori N550 with CCI 200 LR primers. I want to do this with as few components and trips to the range as possible, so was looking to shoot a ladder first to narrow the load range and then an OCW to pinpoint my loads.

I was thinking of shooting at 300 for the ladder but am unsure whether this distance is enough for the ladder to work with the load steps I have planed.

190SMK: 45.2gn to 48.0gn in 0.40gn steps

178HPBT: 46.0gn to 48.8gn in 0.40gn steps

208Amax: 44.3gn to 47.1gn in 0.40gn steps

Anyone see a problem with what I've planned or got any better suggestions?

The rifle is a 26" (1in12) SPS in AICS

Thanks for your time.

 

[timelinex]

Re: Minimum effective range for a ladder test?

From everything I've read, 300 is the minimum

 

[MitchAlsup]

Re: Minimum effective range for a ladder test?

300 is bare minimum, 500 recommended.

 

[vman]

Re: Minimum effective range for a ladder test?

300 is mmmmm ok but 400 is better. 500 is even better yet.

At 300 you still get some degree of bullet drop between charges but it's not profound. If you have terrain features that cause minor vertical then it can give you a false result. The further out you go the more obvious the nodes become.

 

[bolloxinaspanner]

Re: Minimum effective range for a ladder test?

Personally, I don't think you will get that much powder into your Lapua cases. Winchester cases will fit more powder but you will have to do more culling, generally, than with Lapua.

 

[boudin]

Re: Minimum effective range for a ladder test?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JJoplin</div><div class="ubbcode-body"> Try doing a ladder test at 100. When they shoot into a tight spot that's your node. Then take that info to distance and shoot 5 shot groups of the same load. Start in the middle of the node and work up and out. I think you'll find those results a little more rewarding. 50% of the time you will find that your distance load is out of your 100 yard accuracy node.

Keep in mind that reloading is simply a combination that hopefully provides the performance results you were after. You can find a load and change one small detail and loose everything. However changing a separate variable could bring it back to where you were originally. Example to try yourself. Work up a load that shoots with your bullets .010 in the lands. Then seat .010 off the lands. No doubt the group will change. It will not only slow down but the entire ignition is different in the case. By increasing the charge to bring the velocity back to where it was and it will shoot very similar to the way it did before.

Also FYI. Pick up the phone and call the bullet mfg. They generally have a good idea about what makes their product perform it's best. Taking advice on the net about reloading is like sleeping with a prostitute. You never know what you are going to walk away with. Don't let the enter net let you loose sight of common sense.

</div></div>
Never tried a ladder test at 100 yds but I think I'm gonna give it a shot this weekend if I get out. I usually do mine at 400 yds.

 

[turbo54]

Re: Minimum effective range for a ladder test?

I prefer 300 or 400 yards for 308, although i would argue 200 can work. Theoretically, further = better, but in my experience, you start to second guess your hold. Unless you KNOW you can hold 1/2 MOA, I wouldnt suggest more than 400.

That said, I strongly recommend you run at least two if not three iterations of each ladder. People may argue this point, but there simply IS NO ARGUMENT as far as I'm concerned.

 

[vman]

Re: Minimum effective range for a ladder test?

Good advice if you ask me. Doing one ladder is asking for trouble if your not 100% confident in your shooting skills

 

[JWEM]

Re: Minimum effective range for a ladder test?

Cheers for the feedback!

bolloxinaspanner, I think you could be right with not being able to get that much powder in with the 208's, I'll give it a try because I have had 51.0gn(N550) under a 175SMK in win brass(OAL=2.830"). Hopefully tomorrow I'll find out.

When shooting I can hold between 0.75-1 MOA, so anything past 400 will probably just be a waste. Shooting the ladder twice makes a lot of sense, I'm just wondering if it would be worth doing 3 shots of each charge and turning it into a OCW test. Is it possible to get good results from a 3 shot OCW? - I've always used 5 in the past.

In your opinions would you say a 3 shot(of each charge) OCW at 0.40gn intervals is more likely to give me better results that a 2 shot(of each charge) ladder at 0.40gn intervals? Both being shot at 300.

 

[AtOne]

Re: Minimum effective range for a ladder test?

If your doing and OCW test then do it at 100 first. Less variations from wind or shooter error.
Three shot groups work fine and when you've pin pointed your OCW then take it out further to be sure it will work for you.
Good luck

 

[wirehand]

Re: Minimum effective range for a ladder test?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AtOne</div><div class="ubbcode-body">If your doing and OCW test then do it at 100 first. Less variations from wind or shooter error.
Three shot groups work fine and when you've pin pointed your OCW then take it out further to be sure it will work for you.
Good luck
</div></div>

Gonna have to disagree with this statement.
The reasoning behind shooting a round robin in the OCW is for wind and shooting error.
Besides it would have to be a kick ass wind to affect a .308 that much at 300m/y.
100 yards/meters will not show the disparity in POI/POA as a greater distance will, allowing some inaccturate measurments.
Shooting at distance will allow for the bullet to settle down, even though this is a debateable theory.


My routine is 5 shots per charge weight and completing 5 solid dry fires before any shot is taken.
Staying in postion for one string as not to affect NPA between shots.
Check and mark string number at targets between strings.
All the while recording FPS readings of the chrono.

So far it's been working damn well.

 

[rcamuglia]

Re: Minimum effective range for a ladder test?

Shooting an Audette Ladder should be done at the longest range possible if you are interested in really seeing where the accuracy nodes for your rifle/component combo exist. I've been shooting them at 600 yards simply because my range has the F-class berm at that range.

If you can't shoot well enough and want to shoot the test at 100 or 200, then you might as well not shoot one at all. The results will be misleading and meaningless. In fact, if your shooting skills are that poor, even if someone develops a load that shoots in one hole for you, it won't help you. You may as well buy some factory ammo and get some practice.

Shoot the test at a minimum of 300. Shoot Audette's with all of your rifles for development. It will help your shooting skills. You will concentrate on every shot making it as perfect as you can. Not doing so skews the results.

 

[boudin]

Re: Minimum effective range for a ladder test?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rcamuglia</div><div class="ubbcode-body">Shooting an Audette Ladder should be done at the longest range possible if you are interested in really seeing where the accuracy nodes for your rifle/component combo exist. I've been shooting them at 600 yards simply because my range has the F-class berm at that range.

If you can't shoot well enough and want to shoot the test at 100 or 200, then you might as well not shoot one at all. The results will be misleading and meaningless. In fact, if your shooting skills are that poor, even if someone develops a load that shoots in one hole for you, it won't help you. You may as well buy some factory ammo and get some practice.

Shoot the test at a minimum of 300. Shoot Audette's with all of your rifles for development. It will help your shooting skills. You will concentrate on every shot making it as perfect as you can. Not doing so skews the results. </div></div>

Not sure I understand your logic here... why would a "one-hole load" not be of any benefit to a beginning shooter. An accurate load will help you identify when <span style="font-style: italic">you</span> are the problem, and not the load. Maybe it's just me, but I learned a lot more about problems in my form and execution after I started rolling my own and had found a few recipes that were much more accurate and consistent than factory offerings.

And just to play devil's advocate once more (not to mention, quote someone who has much more experience than I):
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JJoplin</div><div class="ubbcode-body">Provided the rifle is accurate time in flight will dictate vertical stringing at distance. Nothing more.......nothing less ........unless you find a way to remove gravity from the equation.
Some common sense should apply. You find nodes at 100 because gravity has very little effect due to the minute time in flight.

I will go as far as to make this statement. If you can come to my range and prove me wrong I'll give you a free APA rifle for your troubles.

Good consistent loads are found at distance. 100 is simply a reference point and a place to find your node. Flat ladder test at distance means you maxed out your powder not you found "magic".

Don't misunderstand the statement. I'm not saying that bullets running at slightly various speed can't impact the same location at distance. What I am saying is don't be surprised when a ladder test goes vertical at distance until you begin to max out your charge.

Anyone up to the challenge? I'm not trying to be arrogant but it's time the horseshit got swept out of the stall.

I would like to add that if you are coming to a match that I'm shooting in I highly recommend you do your ladder test at distance.

</div></div>
Maybe you should take Jared up on his offer since the results of a ladder test done at 100 or 200 are "misleading and meaningless". I assume you can prove that, given your certainty.

 

[rcamuglia]

Re: Minimum effective range for a ladder test?

Sure, glad to help.

While shooting an Audette Ladder the trigger must be broken at exactly the same POA on every shot for the test to have meaning. You're trying to identify the load ranges that the barrel throws bullets to generally the same POI. You want that "group" or node to have as little vertical dispersion as possible. You also want to identify charge weight ranges that the barrel is throwing bullets haphazardly so you can stay away from them.

If your <span style="font-style: italic">shooting skill </span>throws bullets haphazardly, how will you know the culpret for the miss? You or the load?

If your skill is at the level that makes the results of ANY Audette questionable, why even shoot one?

I agree that a known one hole rifle/load will help an accomplished shooter identify the problem. My point was that if the guy's skill level was low, that even the one hole rifle/load may not help him hit anything any better than factory ammo. He certainly won't shoot as well as the rifle can.

As far as shooting an Audette at 100 yards to identify "nodes", I'm sure it can be done but reading the test will be a lot more difficult. ALL of the impacts will be very close together (fired from a good rifle barrel) and actually figuring out the node will be a chore and probably a guess. If you shoot the Audette at long range, the "nodes" will be much more evident and can be identified immediately without a micrometer.

My method is:
1. Shoot Audette at long range. Longer the better. No wind is better.
2. Identify consecutive shots with virtually the same POI and minimal vertical.
3. Load 5 of each of the loads in the node.
4. Shoot groups at any range your skill level allows with the loads.
5. Pick the best load from the groups.
6. Adjust seating depth (if even necessary) to fine tune.

Here's a recent Audette shot at 600 yards:

Loaded the 4 loads in the "node" and shot them...

Shots 14, 15, and 16 were an upper velocity node but too close to max for me and show more vertical. The barrel at those charge levels is less tolerant. I always choose the node with the least vertical.

The flat "node" DOES mean you've found your magic. Bullets impact at different levels not only because of gravity but also because of barrel harmonics; where the barrel happens to be pointing due to many different vibrations when the shot leaves the muzzle. The Audette Test helps identify the tolereable charge weight range for the barrel's best accuracy. The bullet is either exiting the muzzle at or just before its uppermost swing or visa versa. The barrel is "quiet" in movement or at point where it is in slow transition.

I've never seen or shot a "flat ladder". Everyone I've shot or seen shot, strings vertically.

The long range Audette Ladder works it all out.

 

[Queequeg]

Re: Minimum effective range for a ladder test?

10 and 11 look promising!

Curious about your spotting method as 600 yards is a sea of mirage here and tough to spot hits on white paper. I could see a big ass Shoot-n-See type target being practical for me to try this though.

 

[rcamuglia]

Re: Minimum effective range for a ladder test?

I really don't consider 2 shots a big enough node to explore. They may work, but the more shots that impact at the same place the better. It demonstrates that the barrel will be tolerant to a wider charge weight range.

I use a spotting scope to see the shots and with the white paper it's easy. The lowest power scopes I use for LR is 20X and you can easily see bullet holes at 600. These were .338 holes and it was easy. I have a 25X scope on my 6.5 Creedmoor and can see the holes at 600 with just the scope