My 6BR Norma Ladder Test R5 Rifle

[FroggyOne2]

Ok.. went to the range today and tested SIE 107's,dry and moly'd) with RL-15. I started at 28.5grs. I was trying to find two different nodes to work with. RL-15 and the moly'd test didn't do to well I believe, because everything kinda was clumped together. though that there were a few that were outside of the clump. RL-15 and the naked 107's, I found two different nodes first was 29.7 and 30.0 grs of powder and the second one was 30.5 and 30.7 grs of powder. So I am going to try 30.6grs of RL-15 for the 600 yard line. I am perplexed as to what to load for 200 and 300 yard lines.. should I go with the 29.7 or either 29.8 or 29.9?

Frog

 

[FroggyOne2]

Lynn,

thank you so much for the response.. to tell you the truth, I had forgotten about making this post!

As to the load development with the RL-15 and the SIE 107's, I shot in a regional long range match where by the winner of the match was shooting the .284 winchester using Berger 180's, his final score was 967-33, mine was 946-22. The load that I used was 30.6grs of RL-15 with the SIE 107's. Now that may sound like quite a difference, but not having shot prone for over two years and having to relearn a few things, not really knowing how the round would react with the wind and speaking of wind, the first match there was hardly any and shot a 196-9, but the last two matches of the regional, we incured winds up to 35 mph and I was having to aim on the target next to mine in order to hit mine. I believe that the load of 30.6grs of RL-15 is working pretty well with all things considered. The factor I believe that kept my score down is that I was caught a few times by letoffs in the wind.

I will be testing the Berger 108BT's next, but also will be testing some groups with the SIE 107's again at 29.7, 29.8 and 29.9 to see what they look like.

I have also found that this rifle likes 28.5, 30.0 and 31.0 grs of Varget under a moly'd SIE 107. There is a practice session tomorrow, which I am going to try those loads to see how they are working at distance. 28.5 for 200 yards, 30.0 at 300 yards and the 31.0 at 600 yards.

 

[FroggyOne2]

Here is a couple of groups that I shot today with RL-15, the second photo is 29.7 grs of RL-15 with an SIE 107. As I measured it, it appears to be a .166 inch group. The first is with the Berger 108BT to which appears to be a .213 inch group.

 

[FroggyOne2]

Here is the rifle that shot these groups.

 

[gambleone]

How many shots do you shoot in a ladder test? Do you shoot 3 each time you jump 0.1 increments?
Greg

 

[JERRYHM]

Lynn,
What is a ladder test? Do all you BR guys do it?
Jerry

 

[eddyverhoeven]

Though I also have a general idea about what a ladder test is, could someone explain as to how to do it. Might be a dumb question but hey, I'm here to learn.

Many tx

Ed

 

[billmo]

Hey Ed, if you do a search for Audette Method, I think it will give you a fair amount of knowledge. Then you will probably want to fine tune the method to suit your style. It is a very good method to start out with to find a good load but I would not "bank" on being able to duplicate your test. Too many varibles to deal with. Just my opinion. Bill

 

[CatShooter]

Hey Ed, if you do a search for Audette Method, I think it will give you a fair amount of knowledge. Then you will probably want to fine tune the method to suit your style. It is a very good method to start out with to find a good load but I would not "bank" on being able to duplicate your test. Too many variables to deal with. Just my opinion. Bill

I have yet to see a ladder test that was repeatable - and if it's not repeatable, then it means nothing.

The range that it is shot at should not make a difference... if the bullets are 3" apart at 300, then they will be 1" apart at 100 and the closer range does not allow wind to interfere.

If you can shoot three ladder tests and lay them side by side, and they are all the same, then you have something... but if not - then you have nothing.


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[Forum Boss]

The range that it is shot at should not make a difference... if the bullets are 3" apart at 300, then they will be 1" apart at 100 and the closer range does not allow wind to interfere.

Bullets vary somewhat in true BC, even within the same box. This is due to differences in meplats, tip run-out etc. Also, even with the most precise load methods, the muzzle velocity will vary shot to shot.

These factors lead to variances in shot to shot ballistic trajectories that increase as you go farther out in distance. For this reason, a load that holds 1 MOA of vertical at 1000 yards, in the real world, needs to be much better than 1 MOA at 100 yards. So I would modify Catshooter's comment: "if the bullets are 3" apart [vertically] at 300, then they will be no more than 1" apart vertically at 100, and in reality, probably quite a bit less."

 

[jb77]

Catshooter, I disagree, you have evidence of a waste of time.

On another note, several months back you pm'd another member info on using Blue Dot in a 22-250. If it's not too much trouble can you share that with me. Thanks J

 

[FroggyOne2]

I would have to say that it was not the most specific way to find a load.. but my testing did save a lot of powder and bullets in the trial and error method that I used to use..

What I will say is this, using this.. I have found 6 loads that my rifle likes. SIE 107's moly'd 28.5, 30 and 31 grains of Varget.

SIE 107 dry, RL-15 29.7 and 30.6 Grains

Berger 108BT RL-15 30.5 grains.

I have not even tried the Bergers moly'd yet. was going to do that but ended up having to pull a 16 hour shift.. I am still trying to wind down from that!!!!

Frog

 

[FroggyOne2]

I must add that even though I shot this at 100 yards.. and many may say that you can not get enough data at that distance.. it did give me some general areas to fine tunea load.. and that it do for me.. saved me a lot of time..

 

[FroggyOne2]

Lynn,
What is a ladder test? Do all you BR guys do it?
Jerry

Jerry.. first let me say that I am not a bench rest shooter.. I shoot highpower XTC and Long Range..

A ladder test is where you pick a starting load that each case after that you increase the load by say .2, so that you have maybe about 10 to 15 loaded with each round the powder has been increased by .2 what you are looking for is area where the loads, even though they are different.. are indifferent and bunch them together to make a group.. then as you keep going.. they will jump out of the group and start to shoot somewhere else again.. you are trying to find these nodes where the case and bullet don't care so much how much powder is in the case, it still groups.. this is great exp when you throwing charges or using something like a chargemaster or dps III

 

[CatShooter]

You guys just made the case against ladder testing for best loads.

If you are testing for best loads, you have to eliminate all other outside influences. This standard for ANY testing procedure.

The ladder test presumes that there are vibratory patterns in the barrel, and you want the barrel transit time of the bullet to be such tat the bullet is leaving the barrel at one of the extremes of the arc, so the best using the dwell time of the barrel's arc,erroneously called a "node", but you cannot have a node at the end of a vibrating barrel).

Now, at 50 or 100 yds, assuming that there is no strong winds that day, what you see on the target is pretty much what you are getting in bullet launch angles,assuming a decent chamber, etc).

However, if you take the same thing out to 300 or 500 yds, you cannot assume that what you see is what you shot.

As Paul,a.k.a. Moderator) said, note that bullet variance errors enter the pattern... so if you have three exact velocities, you can have substantial stringing if the metplats are so-so...

... and by the vagaries of statistics, you could have a lower velocity, but by chance picked a bullet with a higher BC, and then the next round could have a higher velocity, but a bullet with a lower BC, and you would get a deceptive target... because the selection of bullets is random.

You could have a load that has a ES fo 10, and an SD of 3, but think the load sucks, because of the effects of varying BC,erratic metplats).

When developing any load you need to eliminate variables at each stage, so the results you are getting are due to the ONE thing that you are testing.

This is standard procedure for any testing lab, any you can't trust any test that has several variables changing at once.


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[CatShooter]

Catshoote --

How many loads have you worked up in a "testing lab"?

Lots, I did testing at Columbia University - but not with "ladders".

How many shooters would have resources to a "testing lab"?

It doesn't require a "lab", but it DOES require the same procedures.

Lookie - you are being silly about this.

If you are developing long range loads, or match loads, the process starts when you get the loading "stuff".

To what ever standard you want to apply...

You sort cases.
You trim them, weigh them, do what ever pixie dust things you do.
You weigh the cases, and sort them by weight to what ever standard you like.

You weigh the charges to what ever limit you like.

If you sort bullets, then you do that to what ever level you like. Use bullets that are up to the level of "select" that you will actually shoot in whatever endeavor you shoot. If you are testing loads for a 1,000 yd match or ench rest, you don't test loads with pisspoor bullets, and think you can select better ones later.

If you fuss with metplats, then you clean them up to whatever level you like.
Then you load them with the best dies you can get,to what3ever standard you chose).
Then you check run out, both neck/body axis run out, and bullet/body run out.
Spin test the bullets,if you do that).

So at this point, you have eliminated the following variables...

1 - Case imperfections
2 - case length
4 - Flash holes,if you do them)
5 - Neck thickness variables,to whatever limit you like).
6 - Case weight
7 - Bullet weight,to whatever level you like)
8 - Bullet metplat,to whatever level you like)
9 - Spin test the bullets,if you do that)
10 - Body/neck axis,if you do that)
11 - Bullet/core weight distribution.

At this point, we have eliminated at least NINE variables, and maybe eleven, before firing a single shot.

The only variable left is powder wight.

If you are going to test loads at 300 to 500 yds, and you haven't done most of the above, then you are just out for some suntan.

If you are going to test loads, why would you allow wind and mirage to enter your decisions.

I did try ladder testing when it was first being talked about, and I quickly found that it is like reading tea leaves - you see what you want.

Do the exact same ladder tests five times, and compare them...

... I did, and there was no meaning full correlation.

Guys with hunting rifles think they see something, but it is the randomness of the groups... with top class rifles, you just see the holes go "up"... and the spacing is equal to the velocity differences, distributed by the grouping ability of the rifle.

Would you share your procedures and environment to your own load development?

I just done did that!

How do you suggest others develop loads ?

Any way they want...


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[CatShooter]

Catshooter --

To test "seating depths" and using the same variables,my own), how would you suggest that I test for seating depths of this order:
1) .020" OTL
2) .010" OTL
3) .0" +/-
4) .010" ITL
5) .020" ITL

Why would a "ladder test" not be conclusive to such a test?

One shot at each depth... what would it tell you, other than the gun shoots.

Look, I'm not trying to be sarcastic, but consider this.

Most things have some variables - we remove what we can, but there is always a level that is below our perception - and each year, or decade, we hope to get closer and closer to that perfect "whatever".

Guns have been pretty well put together... back in the early 80's, they were building rifles that could shoot groups in the 0.035" to 0.05" range on a pretty regular basis - so we are not pushing forwards the art and science of loading here...

,an interesting read...)

http://www.angelfire.com/ma3/max357/houston.html

... when you consider what has already be demonstrated as do-able, then you must realize that it is the dummy at the back of the rifle that is the BIGGEST problem, and is responsible for the errors, cuz decent rifles will shoot rings around us when wind and mirage are eliminated... so why allow wind and mirage ti get into the arena testing???

I don't tell anyone how to do anything... I just like to see rumors, wives tales, and fake science die a quick and clean death.

I am open to suggestions and always looking for better ways!!!
I would really like to hear of what better ways you have to offer for load development, that are more productive then the commonly used ladder testing that is so widely utilized by handloaders and competitive shooters.

People use it because they read that others use it, and so it "must be good, right??"

But I read hundreds of postings on websites that someone had a ladder test, ans shows a picture of it for others to evaluate, and you get 20 guys "guessing" at what is there... and none of them agree!!

If it is a valid test,like any test) I should be able to post photos of 20 ladder tests, and:

The ones that were of identical loads should look identical enough that other people would be able to tell which one were done with identical load strings... I have done that at my shooting range, and "Zip".

And the same group of 20 should be able to determine the best accuracy load... I did that, and "Zip".

What I got was a Saturday morning at the range with guesses all over the place, by guys that "swore" by ladder testing.

What I am talking about above is called "blind testing", it is "THE standard" of evaluating any procedure like "ladder tests".

With ladder tests, they don't pass the smell test.


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[CatShooter]

If it works for you, then use it.

But I will ask you the same question you asked me - how many shooters have access to what you are doing...

... I dare say very damn few.

And what do the guys that just load, and have a chrono, do - can their ladders be repeated??

I don't think so.


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[Forum Boss]

I know Jason uses "round-robin" ladder tests extensively at 800 yards+, and he has found HIS version of the procedure effective for the 1000-yard game. For the past two years, Jason has shot some of the smallest groups at 1K at Williamsport.

Jason has his own methodology that seems to work, but he's the guy to explain it. He is NOT, as I understand it, doing the classic Audette style ladder. Jason also uniforms meplats and points his bullet tips, reducing the BC "spread" among bullets.

Ambient Temp--that "other" variable
One caution however--ambient temps,and/or letting the brass sit in your chamber) can throw your ladder test results out the window. I've recorded a 20 fps difference in average velocity in a 6BR shooting 203B--just from leaving the ammo in an ammo box in the sun for 10 minutes. The effect is less with Varget, but it's still there.

Point here is that if you are doing a ladder test, you may get a significant velocity-induced change in Point of Impact,POI), just between the "early" loads in your test vs. your "late" loads, if they've been sitting in the sun for a while.

- - -
Personally, with the standard 6BR, what I've found more repeatable than ladders is "velocity tuning" -- meaning there seem to be particular velocity bands where the groups look real nice,even with different powders), time after time. Once I get into the desired velocity window, then I play with seating depths to try to get my measured ES/SD into single digits.

This is not a knock on using ladders. I've just found with the 6BR, certain velocity ranges seem to be the "sweet spot".

I'll say this about chron testing however--don't be fooled by one 5-shot group shot over a Shooting Chrony. I like to chron at least three 5-shot groups to confirm that a load is consistent. And, for my "match load" I'll chron in cool "morning" conditions, and hot "afternoon" conditions.

Also, brass makes a HUGE difference. You could test a load and get ES=10, SD=4 and be all jazzed. Then put the same load into brass where the necks have work-hardened or you otherwise don't have consistent neck tension and you can get ES=35, SD=14.

That points out another benefit of chronographing your practice shots. If you know a load has repeatedly delivered low ES/SD, and suddenly the shot velocities start getting ugly, you may have isolated brass that is starting to go bad. If you were shooting at 100/200 yards, the effect might not show up on paper, though it would at longer distance.

 

[HPMike800]

Frog:

Your load of Berger 108's and 30.5g RL-15 is probably very hot.

My load was naked Berger 108's, 30.0g RL-15,Fed 205M's,Norma Brass. On a hot day during a prolonged match, The bolt lift became very hard and I even poped a primer. I wiped out about 100 pieces of brass at that match. IMHO RL-15 is to "peaky" in 6BR with heavy bullets and Varget will serve you better in the long run.

Mike