Ladder testing at 1k- Detailed article and video

[Alan Griffith]

Joden,

1) I'm saying "rode hard and put away wet". Once I was finished with barrel break-in, the only thing that ever goes down my barrel is either a bullet or a rod, in conjunction with THE marked up bullet used to determine throat wear. DBC works that well.

I won't argue with GAP nor their reputation and their advice/technique. Though it surprises me they would advise to clean that often. Maybe, using their method, they can get tiny, smaller, groups then someone, like me, who never cleans. The purpose of not cleaning is two fold. 1) POI stays the same. A dirty barrel can and usually does have an impact different than a clean barrel. 2) Too many times, shooters do more harm to a barrel with bad cleaning techniques than not cleaning at all.

2) If done properly, you won't need 30-40 rounds to determine pressure limits. The first 10 rounds fired, in incremental increases, will show you where your "powder" limit is. Those 30-40 fired rounds will show you where your "accuracy node" is.

Alan

 

[seidersjoden]

Joden,

1) I'm saying "rode hard and put away wet". Once I was finished with barrel break-in, the only thing that ever goes down my barrel is either a bullet or a rod, in conjunction with THE marked up bullet used to determine throat wear. DBC works that well.

I won't argue with GAP nor their reputation and their advice/technique. Though it surprises me they would advise to clean that often. Maybe, using their method, they can get tiny, smaller, groups then someone, like me, who never cleans. The purpose of not cleaning is two fold. 1) POI stays the same. A dirty barrel can and usually does have an impact different than a clean barrel. 2) Too many times, shooters do more harm to a barrel with bad cleaning techniques than not cleaning at all.

2) If done properly, you won't need 30-40 rounds to determine pressure limits. The first 10 rounds fired, in incremental increases, will show you where your "powder" limit is. Those 30-40 fired rounds will show you where your "accuracy node" is.

Alan

Your not afraid of putting in the barrel from sulphur, moister, and the carbon build up? I just feel weird about putting the gun up after shooting without even touching the barrel?

Joden

 

[BountyHunter]

I won't argue with GAP nor their reputation and their advice/technique. Though it surprises me they would advise to clean that often. Maybe, using their method, they can get tiny, smaller, groups then someone, like me, who never cleans. The purpose of not cleaning is two fold. 1) POI stays the same. A dirty barrel can and usually does have an impact different than a clean barrel. 2) Too many times, shooters do more harm to a barrel with bad cleaning techniques than not cleaning at all.

Alan

You will eventually get a carbon ring in the throat that will cause high pressure and hard loading unless you keep it clean. Plus seared in like that it will take weeks to get out.

 

[Alan Griffith]

I'm not going to argue with you nor am I going to try and convince you. It's your rifle and your choice. Let's please not turn this thread into a barrel cleaning argument and keep it on 1000 yd ladder testing.

Alan

 

[seidersjoden]

I'm not going to argue with you nor am I going to try and convince you. It's your rifle and your choice. Let's please not turn this thread into a barrel cleaning argument and keep it on 1000 yd ladder testing.

Alan

I know we got off topic, I just know based off your ladder test this isn't your first rodeo and had general questions that I knew you could help me out with. I just prepared my target per your method and hopefully Sunday I get a chance to shoot my fist ladder test.

Thanks Alan

Joden

 

[seidersjoden]

Joden,

1) I'm saying "rode hard and put away wet". Once I was finished with barrel break-in, the only thing that ever goes down my barrel is either a bullet or a rod, in conjunction with THE marked up bullet used to determine throat wear. DBC works that well.

I won't argue with GAP nor their reputation and their advice/technique. Though it surprises me they would advise to clean that often. Maybe, using their method, they can get tiny, smaller, groups then someone, like me, who never cleans. The purpose of not cleaning is two fold. 1) POI stays the same. A dirty barrel can and usually does have an impact different than a clean barrel. 2) Too many times, shooters do more harm to a barrel with bad cleaning techniques than not cleaning at all.

2) If done properly, you won't need 30-40 rounds to determine pressure limits. The first 10 rounds fired, in incremental increases, will show you where your "powder" limit is. Those 30-40 fired rounds will show you where your "accuracy node" is.

Alan

Alan,

Did the ladder test very closely to yours. I messed up a littler by using the same paper for the first two tests and some of the second ladder overlapped on the first..I figured they were afar enough apart but the wind picked up and blew the rounds from the first ladder over into the second. Did the test at 600y. The third ladder I got on video and I used colored markers and got good data but some of the lower charged rounds hit higher than they should of and doesn't make since to me. Plus the mirage was horrible in the san diego desert at 9-12 in the morning. Getting a little discouraged, for me it takes two hours to go to the range. That being said:

What do you think about doing the Optimal Charge Weight Test (OCW) Here's a link, you might have seen this method. Basically you shooting round robin like a ladder test but you shoot 1 round of each load at a different target, i.e., load one is shot at tgt 1, load 2 shot at tgt 2. Then you pick the 3 loads that all hit at the same POI on their respective targets and pick the middle of those loads as the accuracy node, not the load that simply shoots the smallest group. What are your inputs? Sick of waisting gas money and barrel life.

Thanks



OCW Overview - Dan Newberry's OCW Load Development System

 

[Alan Griffith]

Joden,

I know Dan and have talked at length with him about the OCW system. I'm not a fan; of the OCW. Dan's a great guy. I understand the pros and cons of each. If one has the distance to shoot, use that range. If not, shoot the OCW, but then you'll have to run right back out to a "long" range to verify/test the OCW results.

Once you shoot a ladder, mark each impact, then use your phone's camera and take a picture of it not just for posterity but for a "record" of the results. That way, if you do some how double or triple up on impacts in the same zone, you can sluice out the results.

When it comes to environmental conditions, time frame and available supplies, one has to know his limits.

Alan

 

[seidersjoden]

I use a go pro, I use different target paper per ladder, and I see your point in knowing your limits. I know mine as I'm trained in the is field but subject to time availability in shooting long distance, patience i a virtue guess. Next I'll do a ladder with Retumbo, hopefully under better conditions. Thanks Alan.

 

[BountyHunter]

Here is an explanation of how I ladder test step by step.

My methodology is pretty similar after I have done basic research to determine, bullet,primer, and powder combo I want to use/test for each ladder. Now this might be many reloading manuals, others recommended loads, Qload, etc, but I find a "suspected" powder, primer, bullet and case and then work a load that is normally about 2-5 grains below max to 1-2 grains over at .2 to .4 increments depending on case size. Normally this is 15-25 bullets only with 4-5 extra of the lowest charge for initial zero on the other target.

I use the smaller increments as I am looking for a node that often is only .5 to max 1.0 wide and this gives me a easier way to determine it.

1. Shoot ONLY in early morning or evening in no wind conditions.

2. Minimum of 300 yards prefer 400. I have found that seems to be the ideal distance for enough vertical dispersion as the bullets walk up and close enough to see each separate bullet impact with good spotting scope on white target. Shorter makes it to difficult to determine impacts and longer makes it too difficult again to see any impacts.

3. 35P chrono is used. This is absolutely key. Brian Litz's new book confirms why the Oehlers are the best chromos.

4. Minature paper target at bench to plot each round and another sheet to write down each MV for each round. That way I do not lose track of any bullet shot as each is numbered on plot sheet and anytime I go down range to verify impact. I also mark each shot on the 35 P paper as it is shot.

5. Minimum of 1 minute between shots from starting dirty bore, I usually zero at that distance on another target at the side to confirm accurate zero for bottom of ladder target which is normally large plain white cardboard with 1" aiming dot near bottom. I use .3 grain for large cases and .2 for smaller cases as increments.

6. If I am not 100% sure of bullet location, I either walk down or I often use use colored magic markers (4-5 colors) alternating on bullet tips which show up on target. No they will not vary impact points on target. That is used all the time at 1K BR to identify any crossfires on your target.

7. MV as you go up will be linear (ie roughly same FPS each bullet) until you hit a node and then it tends to decrease dramatically for that 2-4 shots and then jump linear again. You will see 3-4 rds with small MV variances normally in the node and then jump dramatically again. You can see on a magnum a jump of 20 FPS and then 3 bullets around 6-8 fps along then it will jump again back to around 20. This is only an example, not always.

Combination of bullet AND MV grouping confirms node and is usually easy to see when you compare the two!! You will have multiple bullets with similar vertical impacts and very low dispersion on MV.

8. I pick a middle node, shoot groups to confirm basic accuracy and ES, SD nodes. I normally find two, maybe three nodes, and one will be in the MV range I am looking for. Many times the top one is at the starting of high pressure point, so often do not use that one. Middle of the node gives me enough variance on temps and other factors that I am not out of the node on any given day. I do not focus on the lowest ES/SD. Once I find a node then it is an "acceptable ES/SD and tight grouping that is confirmed. I normally shoot for single digit ideally but low teens is acceptable with the grouping.

I determine pressure by case head expansion measured with a blade micrometer, primers (but not always accurate as some are softer than others and can be misleading), sticky bolth etc. It is a combination of everything that leads me to determine I am at high pressure. I take it until I see firm signs of pressure and then stop even if I have not shot all the shots IF I am at an acceptable MV and see good nodes.

9. I then try groups at various seating depths at my best grouping and see what depth it likes. For a single shot gun start, .010 in the lands and come out. Magazine gun, start at max magazine COAL and in from there. I start .010 in, come out at .030, .050, .080 and .120 IF a single shot gun. One will be much tighter and then work in between to find the place normally down to .010.

10. If the gun will not shoot 1 MOA, that makes shooting a ladder a little difficult as you do not know what is the real vertical or 3-4MOA grouping "inability", so IMO it is not for every gun.

11. If a gun will not shoot with all this, then another ladder with another powder or bullet combo.

 

[Mikecr]

I think coarse seating depth should be determined before ladder testing. Otherwise, you're testing with an abstract in place.
After the ladder, fine seating adjustments shape grouping.

 

[Alan Griffith]

Mike,

That was me who posted the ? over on Accurateshooter.com about testing for seating depth 1st before running the ladder. Tried it this morning. I had about 12 new Nosler 257 Rob +P cases that had slightly buggered necks right out of the box so I loaded them up with "starting" loads for a ladder. I shot 3-shot groups of .005", .045", .085" and .125" off the lands before starting the ladder. Good test. .005" was the worst (8") and it was a toss up between .045" (3.5") and .125" (3"). Glad I ran it. I ran the ladder with .045" off, had 10 nice shots @ 303 yds in zero wind and nodes at #'s 4/5 and 9/10 with .3 gr increments of IMR 4350 and 115 gr BT from a VERY custom 257 Roberts. This rifle i is known for being very finicky and I've now found another load for it that will be cheap to shoot (blemished Nosler's) and easy on the barrel and cases.

Alan

 

[Mikecr]

It makes sense, right?
If you had just chosen 5thou off to run your ladder(with no particular reason) then resolving best powder from ~2.5moa(8") could have been a lot tougher than from ~1moa(3") to begin.
Now you can shape your grouping tight with fine seating adjustment within 5thou either way from .045". Something there will be better or worse, and there should be a window there to center.

 

[BergerBoy]

That "vertical dispersion" is usually due to your ES changing. Right? The rounds/loads that group well will have a better/more effecient burn. I mean if all your rounds ave an ES under 10 fps they should hit ~ the same area on the target if the wind/atmosphere conditions are the same.

JMO

What say you??

 

[Mikecr]

BergerBoy, there is a saying that only a truth passes all tests.
Your notions fail tests.

If all there was to load development is find low ES, and then 'they should hit ~ the same area on the target'. well then, we wouldn't even need to aim a gun during development. Just keep em between the screens..