Laguna Freak
Well-Known Member
Yes
If 7&8 are badass, what is 9&10, super badass
I think you must be disregarding the print variance in your humor.
243 ladder test h4350 help
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I think you must be disregarding the print variance in your humor.
PApa Black
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7&8 looks like that spot!1,2,7,8. Nice tight group. But makes zero sense
to me.
You have been given some really great advice here by some smart guys. If I were summing up what I think is the best from these guys I'd say you need to do your test over doing the following things.
1. Get a piece of cardboard and paste your bulls eyes carefully on a perfectly straight line going left to right. Hang your target so line is level to the earth. Use bullseyes that have a nice small center and really focus on that exact spot when shooting and follow through to aid with consistency.
2. Shoot 2 to 4 shots of each charge noting velocities with the best chrono possible. As you go up in charge, take note of any pressure signs or heavy bolt lift which indicate maximum charge for that bullet and powder charge.
3. Primarily look at where bullets are going as the load changes not necessarily velocity. What you are looking for is for all the bullets to be as close as possible to the same vertical plane regardless of velocity or horizontal spread.
4. Once you have identified a charge weight where there is little to no verticle spread, do a seating depth test again with at least 3 shots per group to find the tightest group, then refine your charge weight using that seating depth to hopefully find a good tune for your barrel.
5. As a side note, if you don't do this testing on a virtually windless day, you're going to have bullets all over the place which will totally confuse and frustrate you so at least hang up a piece of surveyors tape so you have some idea what the wind is doing to your shots. If it is virtually windless, longer ranges are best for testing, if you have some wind conditions, test at 100 yards to minimize the wind effects. And remember, as you adjust the charge weight, you are really only looking for the least verticle spread. The velocity doesn't really matter at this point, because if you have truly found a good node it will be forgiving of velocity differences anyway. When you do your seating depth testing, you will tighten up the horizontal and the overall group size.
6. Also, don't be surprised if your groups move up, down, or side to side as the charge increases. This is due to the barrel "whipping" around before the bullet leaves the barrel so the bullet is leaving the barrel when it is pointing in a slightly different place each time. This is why you are running the charge weight test, to find the perfect time for the bullet to leave the barrel so you don't have extreme vertical spread.
Hope this helps
1. Get a piece of cardboard and paste your bulls eyes carefully on a perfectly straight line going left to right. Hang your target so line is level to the earth. Use bullseyes that have a nice small center and really focus on that exact spot when shooting and follow through to aid with consistency.
2. Shoot 2 to 4 shots of each charge noting velocities with the best chrono possible. As you go up in charge, take note of any pressure signs or heavy bolt lift which indicate maximum charge for that bullet and powder charge.
3. Primarily look at where bullets are going as the load changes not necessarily velocity. What you are looking for is for all the bullets to be as close as possible to the same vertical plane regardless of velocity or horizontal spread.
4. Once you have identified a charge weight where there is little to no verticle spread, do a seating depth test again with at least 3 shots per group to find the tightest group, then refine your charge weight using that seating depth to hopefully find a good tune for your barrel.
5. As a side note, if you don't do this testing on a virtually windless day, you're going to have bullets all over the place which will totally confuse and frustrate you so at least hang up a piece of surveyors tape so you have some idea what the wind is doing to your shots. If it is virtually windless, longer ranges are best for testing, if you have some wind conditions, test at 100 yards to minimize the wind effects. And remember, as you adjust the charge weight, you are really only looking for the least verticle spread. The velocity doesn't really matter at this point, because if you have truly found a good node it will be forgiving of velocity differences anyway. When you do your seating depth testing, you will tighten up the horizontal and the overall group size.
6. Also, don't be surprised if your groups move up, down, or side to side as the charge increases. This is due to the barrel "whipping" around before the bullet leaves the barrel so the bullet is leaving the barrel when it is pointing in a slightly different place each time. This is why you are running the charge weight test, to find the perfect time for the bullet to leave the barrel so you don't have extreme vertical spread.
Hope this helps
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Dr. Richard Gray
Well-Known Member
You might want to invest in a Bullseye camera system. I have an older 1 mile model. I don't like it connected to my cell phone and much prefer it on my laptop. Anyway, it will eliminate the guessing if shots are in the same hole, as it appears at least 7& 8 are, not sure about 2? Your #3 hole appears to me that it has been hit twice. But the Bullseye will spot each shot as it strikes the target and numbers your shots in sequence. A fantastic system and the newer models appear to be nicer than mine. If these are all at 100 yards. you have some serious flyer problems. Are you using a bench rest, bi-pod, and what body position, prone, sitting, or standing. With a bench rest you take a lot of human error out of the equation.
Dr. Richard Gray
Well-Known Member
You had better watch your charges closely, 40.8 gr of H4350 is over the recommend maximum charge. Wish you lots of luck!
wbm
Well-Known Member
LOL. Yeah there are better ways.
He didnt state what bullet so how do you know unless I missed it or assuming it's a 105 class bullet
new2mud
Well-Known Member
ericbc7
Well-Known Member
it Seems clear to me that ladder tests are Simply a substitute for a chronograph (and a poor one at that). Even expert shots are somewhat at the mercy of the environment which can make an otherwise 1 moa group into a 2 or 3 moa one. In other words, if you are shooting at 300 yds, a perfectly executed shot can easily land anywhere in a 6" or 9" circle given some unexpected wind and you have little idea of what factors in addition to velocity caused that bullet to land at the extreme distance from aim point or center of group. Add to that the uncertainty of a single shot "group" you end up with a lot of data that you can't rely on.
at the very least a 3 shot group will give you a better idea of the group center since that is what I would want to compare between charge weights (CW). The wind proof option is to shoot 3 shots of each charge weight through a chronograph to get good velocity numbers, ES and pressure signs. The CWs that exhibit similar velocities are your nodes and you can choose your best node based on ES. Then you set up your targets at whatever range you like and start shooting groups varying seating depth.
lots of ammo and barrel life is wasted chasing deceptive ladder tests caused by adverse environments and/or technique and it doesn't take long to pay for a decent chronograph with the savings realized.
at the very least a 3 shot group will give you a better idea of the group center since that is what I would want to compare between charge weights (CW). The wind proof option is to shoot 3 shots of each charge weight through a chronograph to get good velocity numbers, ES and pressure signs. The CWs that exhibit similar velocities are your nodes and you can choose your best node based on ES. Then you set up your targets at whatever range you like and start shooting groups varying seating depth.
lots of ammo and barrel life is wasted chasing deceptive ladder tests caused by adverse environments and/or technique and it doesn't take long to pay for a decent chronograph with the savings realized.
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I did miss it, Thanks
If you shoot during load development whether it's a Laddet test, powder or seating in adverse conditions any of it can be skewed.
Every BR shooter I know shoot Ladder tests, they do it for a reason.
Oh I know it's a hunting site but the same principles apply. LR is LR
Every BR shooter I know shoot Ladder tests, they do it for a reason.
Oh I know it's a hunting site but the same principles apply. LR is LR
ericbc7
Well-Known Member
To be clear, it is my understanding that the bullets that group together on a ladder test do so because they have similar velocities. We want to identify the charge weights that correspond to those velocities so we can load in the middle of the node to reduce the effects of small variations in actual charge weights or temperature sensitivity.
I honestly would like to hear an explanation of how a ladder test could give better, repeatable information for finding velocity nodes than a chronograph.
I could see a ladder test giving you other useful information like performance of a marginally stabilized bullet at range or true bc values. 3 shot group ladders might also give you some insight into a rifle's harmonic quirks, but in that case you are not basing your charge weight on velocity nodes. That case involves finding a velocity that works with that rifle/bullet combo and is part of a much more complicated process to find a powder type that has a velocity node that coincides with the harmonics dictated velocity.
As a civil engineer I like to eliminate variables when I am able, particularly when finding velocity nodes Which is so easily and directly measurable. That many benchrest shooters do ladder tests doesn't explain why they do. I can't imagine that its because their ladder tests generate better relative velocity information.
I honestly would like to hear an explanation of how a ladder test could give better, repeatable information for finding velocity nodes than a chronograph.
I could see a ladder test giving you other useful information like performance of a marginally stabilized bullet at range or true bc values. 3 shot group ladders might also give you some insight into a rifle's harmonic quirks, but in that case you are not basing your charge weight on velocity nodes. That case involves finding a velocity that works with that rifle/bullet combo and is part of a much more complicated process to find a powder type that has a velocity node that coincides with the harmonics dictated velocity.
As a civil engineer I like to eliminate variables when I am able, particularly when finding velocity nodes Which is so easily and directly measurable. That many benchrest shooters do ladder tests doesn't explain why they do. I can't imagine that its because their ladder tests generate better relative velocity information.
wbm
Well-Known Member
And that sir is why many don't.
There not looking for velocity info persay, it's my understanding there looking for optimum barrel harmonics- whip which doesnt equate to the Lowest E.S.
Alex has posted a couple times that he knows 20FPS E.S will shoot small at 1,000
Alex has posted a couple times that he knows 20FPS E.S will shoot small at 1,000
