Jet
Gold $$ Contributor
Just giving you a bad time. I think you meant 0.2 increments instead of 0.02 increments for charge weight.
Thanks. That might be a problem. Will correct the typo.
First Ladder ! Please help read !
- Thread starter SavageMark
- Start date
Thanks. That might be a problem. Will correct the typo.
Northridge
Gold $$ Contributor
because "often" they do fall apart, not always the case but enough so that his statement or point is valid..
Shawn Williams
Ok ! Shot 28.5, 28.7, 28.9 and 29.1 !
Heres a pic of 28.7 , measured .5 ! YOWZA ! All other loads were in the x ring .
Northridge
Gold $$ Contributor
that group is trying to lump them up
I think some might be missing the point here but I will try to explain. if you have shot a powder ladder at a yardage of say 400 yards and closer and you have several charge weights at that distance that are "winners" or did not flounder that is great it often will unfold in such a manner as this nice work. But as you extend the yardage by double say 800 yard ore better 1000 yards these ladders will not be so buddy like or have the same affinity to hit the same quadrant on target and carry sound grouping. in my personal case I will 85% rough a rifle in at the 800 yard distance and often I will have three charges that are in fact very close in size and impact quadrant but more often than not as I stack on just 200 more yards the bottom part of my 800 yard ladder in fact will flounder or shit the bed its just how it is when I shoot the same ladder at the 1000 yard distance.... the further you go the worse it will become draw the yardage in 500 or less and the distance is not enough to see the negative but if you look close enough and shoot even that distance you will find good and bad in them as well.
Shawn Williams
The farthest I can shoot is 500 yards . Do u think this load will be ok at 500 ? Or will i need to do another work up ? It’s difficult at this distance being a novice shooter to know whether your shots are on target or if it’s a flier when doing a work up . I mean , there is a chance that 5 shot 1/2” group was a fluke ! Right ?
Northridge
Gold $$ Contributor
It may very well hold up further out 200 yards on the short end is more forgiving and cartridge still has a lot of pep left. shoot it and find out but if your not sure I would load and compare results from 5 & 6 on your charge ladder. good luck shooting and let us know what you come up with.
Shawn Williams
Ned Ludd
Silver $$ Contributor
To expand on a couple of your questions a little more...
1) Shooting a ladder test at increased distance simply stretches out the y-axis in terms of vertical dispersion (i.e. vertical distance between between holes) and may allow you to get a little better feedback from shots that were clustered close together vertically at a shorter distance. The caveat is that you will generally see more horizontal displacement if there is much wind at all. Because you're primarily interested in vertical when doing a ladder test, increased horizontal is usually only a problem if it comes along with increased vertical dispersion due to the topography of the range. Vertical dispersion can also be induced by wind traveling over berms or other terrain features of the range, which can make it harder to interpret the ladder solely based on charge weight. Obviously, it is most desirable to carry out such tests in minimal or no-wind conditions, but we don't always have that option. The predominant wind conditions and topography at your range need to be factored in when deciding what distance to shoot your ladder tests.
2) Because a ladder test typically requires far fewer rounds than group-based tests such as the Optimal Charge Weight (OCW) approach, it is a good practice to load up at least two or three identical ladders and fire them all on separate targets. That way, if any of the individual shots on a single targets exhibited anomalous vertical behavior, there is a chance one of your other targets may reveal it.
3) If we were to test a very wide range of charge weights in small increments using the ladder approach, it would be expected that we would see several charge weight nodes with two or more shots clustered together vertically for each. For reasons of time, effort, cost of reloading components, etc., we typically start with a somewhat narrower charge weight range based on information obtained from reloading manuals, shooting forums, etc. In other words, we start out already having some idea of an appropriate charge weight range to test. More often than not, this charge weight range will be focused in on the middle-ish to upper (max pressure) region, because we usually have a much better idea where max pressure will be on the charge weight curve, and because testing cases less than half to two-thirds full of powder can create other undesirable issues.
Although vertical nodes identified at the lower end of a test range can provide good precision, in my hands it is those nodes that fall a little higher in the charge weight range that seem to be the most consistent, and are at the point where you're not giving up several hundred feet per second velocity (performance). Of course, velocity isn't everything...I'd absolutely pick a slightly slower node for better precision any day. Nonetheless, I find my best loads will usually have a case fill ratio for a given powder somewhere between 93-95% and 101-105%, that yield predicted pressures safely below max pressure, but toward the higher end. Presumably, it is these conditions that provide the most optimal and uniform combustion for a given cartridge/bullet combination. The bottom line is that the targets will tell you where the optimal charge weight needs to be, whether that be at a lower relative charge weight or higher. This statement is perhaps a little oversimplified, but only when you see two (or possibly more) distinct minimal vertical dispersion nodes on a ladder test, one at a lower charge weight, and one at a higher charge weight, will you need to somehow distinguish between them. In that event, it is often useful to continue load development with charge weights centered in both regions and determine empirically from further testing whether one charge weight is a little better than the other, especially at the distance you intend to compete.
The good news is that the more you do these types of test, the better you will become at interpreting what the targets tell you. Like anything else, you gain experience the more you do something. Best of luck with your load development!
1) Shooting a ladder test at increased distance simply stretches out the y-axis in terms of vertical dispersion (i.e. vertical distance between between holes) and may allow you to get a little better feedback from shots that were clustered close together vertically at a shorter distance. The caveat is that you will generally see more horizontal displacement if there is much wind at all. Because you're primarily interested in vertical when doing a ladder test, increased horizontal is usually only a problem if it comes along with increased vertical dispersion due to the topography of the range. Vertical dispersion can also be induced by wind traveling over berms or other terrain features of the range, which can make it harder to interpret the ladder solely based on charge weight. Obviously, it is most desirable to carry out such tests in minimal or no-wind conditions, but we don't always have that option. The predominant wind conditions and topography at your range need to be factored in when deciding what distance to shoot your ladder tests.
2) Because a ladder test typically requires far fewer rounds than group-based tests such as the Optimal Charge Weight (OCW) approach, it is a good practice to load up at least two or three identical ladders and fire them all on separate targets. That way, if any of the individual shots on a single targets exhibited anomalous vertical behavior, there is a chance one of your other targets may reveal it.
3) If we were to test a very wide range of charge weights in small increments using the ladder approach, it would be expected that we would see several charge weight nodes with two or more shots clustered together vertically for each. For reasons of time, effort, cost of reloading components, etc., we typically start with a somewhat narrower charge weight range based on information obtained from reloading manuals, shooting forums, etc. In other words, we start out already having some idea of an appropriate charge weight range to test. More often than not, this charge weight range will be focused in on the middle-ish to upper (max pressure) region, because we usually have a much better idea where max pressure will be on the charge weight curve, and because testing cases less than half to two-thirds full of powder can create other undesirable issues.
Although vertical nodes identified at the lower end of a test range can provide good precision, in my hands it is those nodes that fall a little higher in the charge weight range that seem to be the most consistent, and are at the point where you're not giving up several hundred feet per second velocity (performance). Of course, velocity isn't everything...I'd absolutely pick a slightly slower node for better precision any day. Nonetheless, I find my best loads will usually have a case fill ratio for a given powder somewhere between 93-95% and 101-105%, that yield predicted pressures safely below max pressure, but toward the higher end. Presumably, it is these conditions that provide the most optimal and uniform combustion for a given cartridge/bullet combination. The bottom line is that the targets will tell you where the optimal charge weight needs to be, whether that be at a lower relative charge weight or higher. This statement is perhaps a little oversimplified, but only when you see two (or possibly more) distinct minimal vertical dispersion nodes on a ladder test, one at a lower charge weight, and one at a higher charge weight, will you need to somehow distinguish between them. In that event, it is often useful to continue load development with charge weights centered in both regions and determine empirically from further testing whether one charge weight is a little better than the other, especially at the distance you intend to compete.
The good news is that the more you do these types of test, the better you will become at interpreting what the targets tell you. Like anything else, you gain experience the more you do something. Best of luck with your load development!
Last edited:
I'm reading all this very carefully as I am now putting together a 6BR myself. I have a huge notebook of useful info I have learned from this forum and a few extra helpful members that have gone well beyond to help me figure a few things out!!
Northridge
Gold $$ Contributor
If I may add further input to clarify a lesser charge floundering at greater distance I'm not at all deeming or claiming "any" lesser charge will definitely flounder that would be false statement . What I mean by this point is example when I rough a platform in at 800 yards I will shoot a given ladder and find out where the ladder starts to shoot several tenths to the same point of impact & lack of vertical. usually with correct prep I will find a low velocity spot and a higher velocity window where it will lump 2 charge weights 1 tenth apart and on a special occasion 3 tenth total window where they crash tight in the same quadrant with out shifting or making a move. So from here I will move to 1000 yards and often the lowest part of this wading will fall short or flounder not just some lesser charge but a charge that was in the good at 800 with at least one other charge sometimes 2 will simply fall short. but I can build this same ladder at a lower window where multiples will share same quadrant as well but say 100 FPS slower but same thing as I step out to 1000 to verify my adjustments or document winner the lowest will fall short often , not a random lower charge but one that is apart of grouping with multiple others at earlier 800 yard distance. happy tuning everyone hope this helps folks understand what Im trying to share.
Shawn Williams
I haven’t got my bullet run out sorted out yet so I am anywhere from .002 to .006 runout . Im a machinist so I made a bushing with a .27 hole in it . Stick the round in up to the shoulder and apply a little pressure , bending the neck to adjust run out to maybe .002 . I know the correct way is to manage run out problems with the press . But it’s too late now . All 50 rounds are loaded and run out corrected to .002 . Just wondering if anybody else does this .
Try a Harrell’s FL Bushing Die..
Northridge
Gold $$ Contributor
I personally have in the past, but these days I do not fuss with loaded round run out...
Shawn Williams
Northridge
Gold $$ Contributor
Quick update ! I took out the neck bushing in the F/L die and sized the case . Put the bushing in my Wilson neck sizing die and sized the neck . PRESTO !
.001 fricken run out on 2 rounds in a row . I love it !!!!!!! No more straightening !!!!!!!!
If it’s working for you and you don’t mind sizing in two steps all is well..
I don’t claim to be an expert but I will make a couple recommendations. I think you are looking at a ladder that is difficult to interpret. If you have the ability to test at 500 yards the target will likely be easier to interpret since you are looking for a point where multiple charges print at or near the same elevation. Even at 500, single shot ladders can be tricky to interpret. I have had some success doing so but you do run the risk of one errant shot pointing you in the wrong direction. As an example, here is a 500 yard 6BR Improved ladder I shot a week ago.
I guessed my node I wanted to pursue was 30.5 but now I think I got lucky. 30.4, 30.5 and 30.6 showed about half an inch of vertical so I picked the center and shot a 4.5” group at 1K but I’m glad I didn’t stop there. I also liked 30.7, 30.8 but the second ladder test, this time at 1K told a different story.
Please note there are two shots for each charge. I actually started with three but a surprise wind shift forced me to finish the test with 2 shots per charge. On the first ladder, 30.4 printed above 30.6 and below 30.5. Not so on this target, and I put more faith in this one.
Now 30.5 and 30.6 still seem to overlap but 30.4 prints low. Next group testing will be at 30.55.
30.7 and 30.8 printed together at 500 but at 1K the second 30.8 shot which you can’t see in the photo, printed about 6” higher than the first. Had I chased say 30.75 I would have been wasting time.
The best advice I can give would be shoot ladders at the longest distance possible, if not the range you intend to compete or shoot at. Wait for the best conditions you can. Shooting multiple shots, especially as the range gets longer, should improve your confidence level in the results.
Dave.
Last edited:
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.