First time ladder test
- Thread starter liltank
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Andy grubb
Active Member
For me the two main reasons for a ladder test are 1: to find max load by looking for pressure signs. 2: to find best grouping by shooting 3-5 shot groups at a certain gr charge. It looks to me like you were shooting one round at each load so your target won't tell you anything at this point. Single round load is a great way to look for pressure sign and get velocities. And don't be surprised to say load 5 rounds at 45 gr and have your velocities differ by 10-15 fps between rounds. I normally start my ladder tests with 5 rounds per charge and go up in .5 gr increments to max. Shoot groups and find accuracy. Then you can tweak by .2 or .1 grs. If you find a load where you get good accuracy don't go crazy trying to tweak it. We all want to hit a dime at 1000 but less than 0.1 % of us ever will.
I read the tea leaves this way 
45.0-45.4 has very low velocity change, but also has a lot of vertical. IMO the velocity AND vertical should both be low, to confirm a good node.
What looks interesting to me is 45.6 to 45.8. If there is no pressure there, I would try to take it a little higher and see what's there.
45.0-45.4 has very low velocity change, but also has a lot of vertical. IMO the velocity AND vertical should both be low, to confirm a good node.
What looks interesting to me is 45.6 to 45.8. If there is no pressure there, I would try to take it a little higher and see what's there.
doverpack12
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I like 45.6-45.8. Either push a little higher or load right between them and shoot to confirm groups and velocity and es
Lonewolf74
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I would say 45.4-45.8 is looking to be your node if your confident there where no mistakes in your shooting. Hear you have very little vertical stringing even with some velocity increase.
I too would shoot another test starting at 45gr and go to 46.2 or 46.4 if you didn't have any pressure signs at 45.8.
I too would shoot another test starting at 45gr and go to 46.2 or 46.4 if you didn't have any pressure signs at 45.8.
I agree with the prior comments about looking at extending the high end if pressure and case capacity allow. I have sometimes experienced velocity jumps at the high end if the load becomes compressed. Otherwise, I would agree with your assessment and hone in on the 45-45.5 charge range, with group size, and ES testing with replicates.
There are two different ways to utilize the ladder test both of which are looking for small vertical at long distance. There is ZERO usable data in your target. You may get lucky and pluck the right load out of something on it or by listening to the previous posters but it will be luck. One could argue that the velocity data could point to the best load but I have on several occasions found loads that had excellent extreme spreads yet would not group well at long range. A ladder should be performed as far as you can get out to 1000 yards. It should be started with one or two rounds per charge and later 3 each when you find the node to fine tune it. If you can not get farther out use the OCW method. I can show you several targets just like yours in which the smaller groups across a few tenths of a grain will never repeat. Either do a proper ladder at distance or do an OCW and repost.
I have had excellent results extrapolating my 200 yard ladder data to 1000 yard performance with several rifles, particularly with the advances in chronographs that deliver accurate velocity(Magnetospeed/LabRadar). It used to be luck when using optical chronographs...at least for me. I believe that this is where the choice of bullet makes a big difference. When 1000 yard results didn't extrapolate or accuracy fell off, it was generally a bullet change or (BC adjustment) that was required. For long range shooting it's very important to select a well proven bullet with solid ballistic information. With a stable bullet, the physics of (an accurately measured) velocity and angular dispersion aren't going to change, other then the effects of wind/air density. The vertical dispersion at 1000 yards will be more pronounced due to the velocity/charge weight for a given load. This is generally going to be in the 5FPS/.1gr range. At 1000 yards the vertical dispersion will be, at the very least equal to the point of impact change due to the change(or spread) in velocity(ex. 1.0gr change in charge=50FPS). With my 6.5x47 this is about 12". My ES for my load is 10 FPS which does give me an average 1000 yard vertical of <3". While I'll certainly test and fine tune at long range, load development/ladder testing at 1000 yards IMO is un-necessary and quite cumbersome due to environmental factors.
This is a recent 200 yard ladder and final load that was chosen for my PRS rifle in 6.5x47. Results correlate to 1000 yards.
liltank
Well-Known Member
This shot in a 30" barrel using RL22. 6.5 Creedmoor shooting 147 ELD-M's.
I wanted to go higher, but I was getting a stiff bolt lift at 45.6 and 45.8. Book max on Sierra load data for the 150 is 46.2. It's weird because a max charge for RL19 is 46.4. I thought RL22 was a slower powder.
I was having trouble finding stability in my SD's with faster powders. I was using 4451. The lowest SD's I could get were low teens. This is using the magneto speed.
I do currently have a load with RL19 that has an SD of 8. Two groups printed a 5 shot group of 1.8" and a 3 shot group of 1.7" at 500yds. Velocity is 2842.
I wouldn't mess with it, but according to the Hornady 4DOF, RL22 has a better temp stability compared to RL19. Therefore I thought about trying 22.
Normally I do the OCW test. Thought I would try the ladder after watching a test done by the 65 Guys.
I wanted to go higher, but I was getting a stiff bolt lift at 45.6 and 45.8. Book max on Sierra load data for the 150 is 46.2. It's weird because a max charge for RL19 is 46.4. I thought RL22 was a slower powder.
I was having trouble finding stability in my SD's with faster powders. I was using 4451. The lowest SD's I could get were low teens. This is using the magneto speed.
I do currently have a load with RL19 that has an SD of 8. Two groups printed a 5 shot group of 1.8" and a 3 shot group of 1.7" at 500yds. Velocity is 2842.
I wouldn't mess with it, but according to the Hornady 4DOF, RL22 has a better temp stability compared to RL19. Therefore I thought about trying 22.
Normally I do the OCW test. Thought I would try the ladder after watching a test done by the 65 Guys.
Sure they don't mean RL23? RL22 is not know for temp stability at all.....
liltank
Well-Known Member
They are showing that RL19 has a 1.23fps change per degree. RL22 shows .6fps per degree
Interesting. Never used the 4DOF. I looked but could not find the temp data for powders. Where do they have the temp data for powders? Thanks.
Found it. That's really cool. Wonder how they cam up with those numbers. I have never seen any truly verified data like that for temp sensitivity.
They have .21 for RL23. They have .73 for H4350 though. The H4350 number seems off to me though... I have tested it and pretty sure it wasn't that high.
liltank
Well-Known Member
You have to build your load data. Then use one of the powders they list.
