I did a ladder test this AM at 300 meters using .308 Sierra 175s and Varget. Savage model 12 with Criterion barrel. No wind. After looking at it, I realized that I don't have a clue as to how to interpret it and was hoping that someone could give me some help on this so I can go ahead with the correct charge to determine seating depth. May be way out of my league here.
Ladder Test
- Thread starter Jayhawker
- Start date
jackie schmidt
New member
Apollo
Jason Stanley
Jayhawker,
I like ladder tests and do them quite often as a starting point for load development. What you are looking for are multiple (3-4) shot groupings like your 1,2 or 7,8 or 9,10. Maybe, part of the reason you are only seeing two shot groupings is you are going up by .3 grains. Something else to consider is that you used a 175 gr bullet and shot 10 shots. Did the barrel get hot on you? Did you shoot any fouling shots? You don't have to reply to those questions - just something to think about.
If this was my rifle - I would skip right past the 41.8 and 42.1 grains (however, keep this as a back up in case the upper charges don't work out). I would go right to the 43.6 (#7) and go up by .1 grains to 44.5 (#10) assuming no pressure signs. So, 43.6, 43.7, 43.8 etc to 44.5. That should be 10 shots again. If you do this, please post the picture of that target.
edit: In terms of seating depth - I always use the longest COL during ladder testing. That means I only have one way to go when fine tuning.
I like doing my load ladders at 200 and use 3 wind flags.
Hope this gives you a direction in which to head. Good luck.
Stanley
I like ladder tests and do them quite often as a starting point for load development. What you are looking for are multiple (3-4) shot groupings like your 1,2 or 7,8 or 9,10. Maybe, part of the reason you are only seeing two shot groupings is you are going up by .3 grains. Something else to consider is that you used a 175 gr bullet and shot 10 shots. Did the barrel get hot on you? Did you shoot any fouling shots? You don't have to reply to those questions - just something to think about.
If this was my rifle - I would skip right past the 41.8 and 42.1 grains (however, keep this as a back up in case the upper charges don't work out). I would go right to the 43.6 (#7) and go up by .1 grains to 44.5 (#10) assuming no pressure signs. So, 43.6, 43.7, 43.8 etc to 44.5. That should be 10 shots again. If you do this, please post the picture of that target.
edit: In terms of seating depth - I always use the longest COL during ladder testing. That means I only have one way to go when fine tuning.
I like doing my load ladders at 200 and use 3 wind flags.
Hope this gives you a direction in which to head. Good luck.
Stanley
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I'll look into this. I am not shooting a bench rifle but just want to get the best from what I've got. Shooting in damp, cool weather with no mirage and dead calm conditions. (6 AM) Always use fouling shots. What is the significance of using a 175 grain bullet and 10 shots? If not going up by .3, what should I use? I shot at 300 meters because I had read elsewhere that there would not be enough spread vertically up the target to see clear groupings if I shot less distance. This forum is obviously a bit out of my league but I've gotten good information which I appreciate.
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vtmarmot
P Magoon, Livin' Free NH
I agree with going up by tenths of a grain. Three tenths is giving you too-wide gaps. If it were me, I'd start at 43.5 and go up by tenths to 44.6 - 12 shots. Find the three closest and the midpoint is your load.
With your first effort, you've found two general nodes. The higher one is likely going to be the most versatile at various yardages and conditions. Now is the time to narrow things down.
With your first effort, you've found two general nodes. The higher one is likely going to be the most versatile at various yardages and conditions. Now is the time to narrow things down.
Apollo
Jason Stanley
Shooting in damp, cool weather with no mirage and dead calm conditions. (6 AM)
Just from experience - sometimes that is worst time to shoot. Calm conditions is when the "gremlins" come out. However, if it is working for you, keep doing it.
What is the significance of using a 175 grain bullet and 10 shots?
That is a big caliber with a big bullet. Shooting 10 shots will generate a lot of heat. Shooting a hot barrel is bad juju.
If not going up by .3, what should I use?
Now that you have it narrowed down some, I would go up by .1. For example 43.6, 43.7, 43.8 etc up to 44.5. (again assuming no pressure signs are noticed)
I shot at 300 meters because I had read elsewhere that there would not be enough spread vertically up the target to see clear groupings if I shot less distance.
Yep, that is fine - if it is working for you keep doing it. I personally like 200 yds for ladder testing because it is far enough for me to see changes, yet not so far that conditions become more of an influence than the load itself.
This forum is obviously a bit out of my league
Absolutely disagree. These types of questions are exactly why this forum exists. We can share information learned from previous sharing or personal experience - which hopefully will save the original poster (you in this case) time/$ and make the learning happen faster/easier. Keep asking questions.
Hope this helps. Let us know how your tuning process goes.
Stanley
Just from experience - sometimes that is worst time to shoot. Calm conditions is when the "gremlins" come out. However, if it is working for you, keep doing it.
What is the significance of using a 175 grain bullet and 10 shots?
That is a big caliber with a big bullet. Shooting 10 shots will generate a lot of heat. Shooting a hot barrel is bad juju.
If not going up by .3, what should I use?
Now that you have it narrowed down some, I would go up by .1. For example 43.6, 43.7, 43.8 etc up to 44.5. (again assuming no pressure signs are noticed)
I shot at 300 meters because I had read elsewhere that there would not be enough spread vertically up the target to see clear groupings if I shot less distance.
Yep, that is fine - if it is working for you keep doing it. I personally like 200 yds for ladder testing because it is far enough for me to see changes, yet not so far that conditions become more of an influence than the load itself.
This forum is obviously a bit out of my league
Absolutely disagree. These types of questions are exactly why this forum exists. We can share information learned from previous sharing or personal experience - which hopefully will save the original poster (you in this case) time/$ and make the learning happen faster/easier. Keep asking questions.
Hope this helps. Let us know how your tuning process goes.
Stanley
R.G. Robinett
"That'll never work."
Damn, it, Stanley, that'll never work!
I need you to come over and train BIG MIKE for me . . . it appears that he's back to stay, and too much for me to handle. RG
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I would load for 3 shot groups with the top 4 loads on the ladder and and under wind flags at 100 pick the best load and on then work on seating depth with that load . then take back to 300. ES will show you vertical also..... jim
And Then The Seating Test
Attached is another picture, this time of a seating depth test I did. I had planned on following through with some of the suggestions I'd read but grandfather duties are calling and I'll be traveling soon. As you can see, I selected 43.7 Varget and seating depths of 0.00 through .020. This test was shot at 200 meters. The only depths that make sense to me are the 0.00 and the .006. I saw no high pressure signs. Like the ladder test, these results are somewhat confusing to me. Groups 4 through 7 look like a bad day at the range more than anything else. Any comments are appreciated.
Attached is another picture, this time of a seating depth test I did. I had planned on following through with some of the suggestions I'd read but grandfather duties are calling and I'll be traveling soon. As you can see, I selected 43.7 Varget and seating depths of 0.00 through .020. This test was shot at 200 meters. The only depths that make sense to me are the 0.00 and the .006. I saw no high pressure signs. Like the ladder test, these results are somewhat confusing to me. Groups 4 through 7 look like a bad day at the range more than anything else. Any comments are appreciated.
Attachments
vtmarmot
P Magoon, Livin' Free NH
With three shot groups, you don't have enough information to choose between groups 1, 2, 3, 6, and 8. There are too many things that can affect the size of a given three shot group to draw hard conclusions. The goal of the ladder test is to get you close to a good powder charge. This is a different animal. You need more shooting to choose a seating depth. It's not surprising that there might be more than one viable depth. Also, you have not tried anything hard into the lands. For grins you might want to try more shots at .014 and .020 off. With more shots in the groups, those could turn out to be an option.