Ladder test results- need help determining next steps

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dlau

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Hi- I hope you long distance shooting gurus can help lend some of your experience

I did a ladder test starting at 43 grains and moving in .5 grain increments to 45grains. Top left is 43, top right is 43.5, and to right is 44. I was hoping to see a pattern where the group would tighten or open up, but I’m not sure what the results are telling me. In general I see the groups move up and to the right as I increase the powder charge, and that is to be expected, but I’m not sure what I should try next to develop a load for this rifle

https://drive.google.com/file/d/1F5I1k49_avMaoTLm0U9fulBa2Su78GgF/view?usp=drivesdk

These are 5 shot groups at 100 yards. Wind was coming from the left in gusts so I did my best to wait for it to calm down. I was shooting with a bipod and sandbag in rear

My setup-
155 amax in .308, 4064 powder, .015 off the lands, 26” barrel 1 in 12”, savage 10FP.

Thank you


1F5I1k49_avMaoTLm0U9fulBa2Su78GgF
 
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Point of impact shifts between loads is normal. When load developing, you're not really concerned with hitting the bull every time, you are maintaining the same point of aim and checking your groupings.

Take your targets and measure your group sizes to determine your most accurate load and fine tune from there.

Did you chronograph your shots?
 
You can't ladder test at 100 yards as the vertical dispersion won't be enough to determine your nodes.

Looks like you are doing group tests if I am reading your post correctly?

By looking at your results as group tests there is something the rifles doesn't like.

You should be starting at 43-44 and going up to 47-48gr , go in .3 increments for your .308.
 
Knowing the velocity is a big help to try and lower your vertical spread at distance. But if you don't have a chrony I would consider running loads 3 and 5 again at a distance at least 200-300yards (big target). Take your time and see how the shots spread out. Certainly looks like there is potential. Also if down the road you aren't impressed I wouldn't hesitate running a heaver bullet. My last two 1-12 (308s) shot great with 178 ELDs and A-Max, they seem to stay much more stable out past 700 than the lighter ones I've tried. Cheers
 
Kelly has given some good info
ladders are best suited for longer distances 300 . my preferred is the Audette ladder (using hard jam)
308 win is a mid size cartridge incremental increases should be .3. .5 is a bigger jump and better suited for larger cartridges eg: 300win mag.

based on your targets what powder charge is the bottom right. it has 4 shots under 1" and one which dropped out the bottom. If this is a load you tested retest that charge weight and see if all 5 group together. if promising start testing seating depth.

IF you are limited to 100 yards; check out Erik Cortina 100 yard testing
https://forum.accurateshooter.com/threads/long-range-load-development-at-100-yards.3814361/

Cheers
Trevor
 
I hate to be a wet rag here, but I'm not sure what is expected from this exercise.

In all honesty, none of the groups are all that promising... Maybe the top right isn't bad. It's just unrealistic to use an analysis method that applies to a precision rifle and use it on an average rifle.

Try to be realistic about your expectations.

If you find a bullet and load that starts producing better groups, then you can start refining from there, but for now, those groups are not conclusive.

What you should be looking for is a shift in group placement as the load is changed. You are likely to find that groups will adopt a POI change as the load is changed. Some rifles more than others.

What you are looking for is a certain load that is at one extreme POI or the other. That's where the barrel harmonic is at the end of a vibration cycle and where you will shoot your best groups.

Personally, I usually start this process in 1/2 grain increments just as the Op did, but I use a much wider powder charge range, maybe 3 or 4 grains.

Hopefully you can find something that produces better groups, then it will make more sense. If that's the best it shoots, then don't try and polish it up... Just accept what you have and roll with it.
 
dlau said:
Hi- I hope you long distance shooting gurus can help lend some of your experience

I did a ladder test starting at 43 grains and moving in .5 grain increments to 45grains. Top left is 43, top right is 43.5, and to right is 44. I was hoping to see a pattern where the group would tighten or open up, but I’m not sure what the results are telling me. In general I see the groups move up and to the right as I increase the powder charge, and that is to be expected, but I’m not sure what I should try next to develop a load for this rifle

https://drive.google.com/file/d/1F5I1k49_avMaoTLm0U9fulBa2Su78GgF/view?usp=drivesdk

These are 5 shot groups at 100 yards. Wind was coming from the left in gusts so I did my best to wait for it to calm down. I was shooting with a bipod and sandbag in rear

My setup-
155 amax in .308, 4064 powder, .015 off the lands, 26” barrel 1 in 12”, savage 10FP.

Thank you


1F5I1k49_avMaoTLm0U9fulBa2Su78GgF
Click to expand...

Things to consider:

how stable is that bipod? If unsure, consider a stack of sand bags or a pedestal rest to eliminate one source of error
Check to ensure the throat is not too long for the 155. Right now, my gut says this bullet is not to the barrels liking. If you have access to a 175gr bullet, try that first.

Ensure nothing is loose in the scope, rings, base or action.

Do consider testing further with 200yds as a nice min with 300yds better.

For the 308, I like to go in 0.3gr steps but only shoot 2 to 3 rds per step. If you make a good shot, are stable, and the first two are miles apart, I see no point in burning more rds proving that load sucks. If the set up is correct, you will see the groups shrink, then expand as you go into and out of your node... but further away makes this more obvious.

When you find nodes of interest, then go back in 0.1gr and bracket the most interesting load. Now you can expand to 3 to 5 rds per step and see how the shots land. If the barrel and bullet and handloads are working together, you should be able to see better and worst even at a 0.1gr step... when testing at 200 to 300yds. For a factory barrel, if I can reliably get to 1/2 to 2/3 MOA, I am happy... and that is the average of multiple groups.

Do keep an eye on barrel heat. Until you can confirm the stability of that barrel, I would plot and pay most attention to the first 3 rds in a string... if the 4th and 5th always get bigger, the barrel is affected by heat.

Otherwise, you are on the right track...

Jerry
 
Besides the fact that the worlds leading ballistician says that positive compensation is not really a real effect, not with the quality of todays rifles and free floating barrels, ladders such as the ones you are shooting (which are a form of positive compensation loading), seem to be confusing as hell for people.

I've seen a lot of people chase their tails on CGN with these kind of ladders, trying to read the tea leaves to figure out what the best load is.

My personal suggestion, is to use a decent chronograph to develop a load with the charge weight that gives good ES/SD, and from there testing the bullet seating depth to optimize precision. This can easily be done at 100 yards, and if done properly, will give you a good shooting load from 100 yards to 1,000+.
 
Potshot21 said:
Point of impact shifts between loads is normal. When load developing, you're not really concerned with hitting the bull every time, you are maintaining the same point of aim and checking your groupings.

Take your targets and measure your group sizes to determine your most accurate load and fine tune from there.

Did you chronograph your shots?
Click to expand...

Good point, I do not have a chronograph but will look into getting one. At 43 grains, it looks like it's about 1.5" above the aiming point, and at 45 grains it's 3" above. I was hoping to see an interesting node, but as others have pointed out, there's other variables to consider.
 
Trevor60 said:
Kelly has given some good info
ladders are best suited for longer distances 300 . my preferred is the Audette ladder (using hard jam)
308 win is a mid size cartridge incremental increases should be .3. .5 is a bigger jump and better suited for larger cartridges eg: 300win mag.

based on your targets what powder charge is the bottom right. it has 4 shots under 1" and one which dropped out the bottom. If this is a load you tested retest that charge weight and see if all 5 group together. if promising start testing seating depth.

IF you are limited to 100 yards; check out Erik Cortina 100 yard testing
https://forum.accurateshooter.com/threads/long-range-load-development-at-100-yards.3814361/

Cheers
Trevor
Click to expand...

Hi Trevor- thanks for the link, some good information to absorb! The bottom right is 45 grains. I feel I can go higher, but as mentioned, in .3 increments. I'm limited to 100 yards at my range unfortunately.
 
Maple57 said:
I hate to be a wet rag here, but I'm not sure what is expected from this exercise.

In all honesty, none of the groups are all that promising... Maybe the top right isn't bad. It's just unrealistic to use an analysis method that applies to a precision rifle and use it on an average rifle.

Try to be realistic about your expectations.

If you find a bullet and load that starts producing better groups, then you can start refining from there, but for now, those groups are not conclusive.

What you should be looking for is a shift in group placement as the load is changed. You are likely to find that groups will adopt a POI change as the load is changed. Some rifles more than others.

What you are looking for is a certain load that is at one extreme POI or the other. That's where the barrel harmonic is at the end of a vibration cycle and where you will shoot your best groups.

Personally, I usually start this process in 1/2 grain increments just as the Op did, but I use a much wider powder charge range, maybe 3 or 4 grains.

Hopefully you can find something that produces better groups, then it will make more sense. If that's the best it shoots, then don't try and polish it up... Just accept what you have and roll with it.
Click to expand...



That's a great question. The rifle is a factory Savage 10FP LE with a MDT chassis. It's not a Ferarri, but I'm curious to see what potential it has and what I can do to get the most out of it. If it's a sow's ear, it's a sow's ear... I don't know what I have yet. I am getting a lot of great information that I'll use in the next batch, and we'll see what it does. But I do thank you for your advice.

Derek
 
Mystic Precision said:
Things to consider:

how stable is that bipod? If unsure, consider a stack of sand bags or a pedestal rest to eliminate one source of error
Check to ensure the throat is not too long for the 155. Right now, my gut says this bullet is not to the barrels liking. If you have access to a 175gr bullet, try that first.

Ensure nothing is loose in the scope, rings, base or action.

Do consider testing further with 200yds as a nice min with 300yds better.

For the 308, I like to go in 0.3gr steps but only shoot 2 to 3 rds per step. If you make a good shot, are stable, and the first two are miles apart, I see no point in burning more rds proving that load sucks. If the set up is correct, you will see the groups shrink, then expand as you go into and out of your node... but further away makes this more obvious.

When you find nodes of interest, then go back in 0.1gr and bracket the most interesting load. Now you can expand to 3 to 5 rds per step and see how the shots land. If the barrel and bullet and handloads are working together, you should be able to see better and worst even at a 0.1gr step... when testing at 200 to 300yds. For a factory barrel, if I can reliably get to 1/2 to 2/3 MOA, I am happy... and that is the average of multiple groups.

Do keep an eye on barrel heat. Until you can confirm the stability of that barrel, I would plot and pay most attention to the first 3 rds in a string... if the 4th and 5th always get bigger, the barrel is affected by heat.

Otherwise, you are on the right track...

Jerry
Click to expand...

Hi Jerry, I actually wrote you when I got this rifle about 12 years ago, and your recommendation was to start with the 155 Amax! I'm just getting the time now to get back into it, so very much appreciate your experience and input!!

Some answers- the Bipod is pretty standard, and I can switch to sandbags to really get it stable. COAL measurement is 2.813, which is -0.015 off. I've double checked the tightness of all the screws, but should do so with a torque wrench. Barrel heat probably was an issue as it was hot to the touch and I was maybe waiting 45s to 90s between shots.

Great tip about just using 3 rounds per step.

For the 175, any recommendations? Also, start it .015 off the lands?

Happy shooting!

Derek
 
10 to 15 thou is a nice start for any bullet... you are just looking for the node. Then you refine charge and/or seating depth to finalise tune. Wow, that was a project from a long time ago. If you want to keep with the 155gr Amax, just work up in 0.3gr increments until you hit max loads.

When I see the groups posted, I dont see any pattern. So either you have jumped over each node.. or the bullet and barrel just aren't getting alone... or the follow through needs to be improved.

I would like to say the rifle can shoot sub MOA... if you decide on the 175gr Sierra, then use H4895 or Varget if you still have issue with 4064.. you shouldn't but....

It can be a bit of a journey but part of the fun of load tuning.

Good luck.... If I can help with stuff, let me know

Jerry
 
So I use Audettes ladder for load development and other than the 10 shot method works but I like shooting so don'[t mind the extra 10-20 rounds. If you don't have a chrony then audettes is the only thing that works. I have access to a range that rarely has anyone on it so can do a couple different things that help.
1 You need to back out to at least 200m preferably 300m
2 Use a lead sled or sand bags. It is super important that the same point of aim be used for every shot. I prefer to use the same target for the entire test.
3 Do not adjust anything once you start. It does not matter where the bullets are hitting the target. You should have your rifle roughly sited in to your middle loads. Fire a couple shots first to warm up the barrel and make sure you hitting paper. No shame in using a BIG target made out of cardboard with a dot in the center. It is surprising on some rifles how big the ladder is.
4 I use the same target for the entire test and mark each shot with a marker. (I use a spot scope and take notes, going down and making target between each 4 round string)
Allows a bit of cooldown.
5 Load a wider ranger. Start just below mid load and work your way up in .3 or .5 gr increments. Seating depth primers etc are constant. I go a couple over max watching for pressure of course.
6 I like to mix up what I shoot meaning I start at bottom load for 1 shot, 2nd for 1 etc then through again. I load 2 shells at each load. I think mixing it up stops self compensating to shoot tight groups.
7 You will see the shots work there way up and sometimes accross the target. You will get a group of several loads that are close together. Middle load of this group is your optimum charge (optimum velocity)
8 Once you have this number use seating depth to tighten the group. Load in groups of five with the optimal charge but vary seating depths in small increments. Do not adjust scope. Use sandbags. This you can do at 100m. Shoot in strings of 5 and measure the closest 3. Tightest group is you seating depth. Longish process but works.
9 If you can access a chrony you can replace the ladder with the ten shot method but still need to play with seating depth.
 
I'd scrap the first test,change powder and bullets.
I've never had much luck with 4064,or amax.

Varget and Nosler works well.
 
I agree on a powder change if it’s all over the map. My 270 hated 4831, first three shots were moa instantly when I changed to RL22. Did powder and seating depth tests after that.
 
Try to find some Sierra Match Kings 155 or 168 for punching paper there hard to beat easy to tune my savage liked Varget and the 168s 25thou. off the lands.
Ditch the bipod unless its a crazy good one like Jerry's Mpod as stated above make up some sand bags or buy a pedestal type front rest and keep trying shooting tiny groups
takes a lot of practice and concentration
 
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You are good with imr 4064, its just not the new guy, it had been around for a long time, If you have lots... if you don't then you could look at other powders
- 155gn - 175gn bullets consider IMR 8208, N140, Varget, AR Comp. also recommended H4895 but i have never used this powder

Your 45 load looks the flattest but dropped shot and the amt of horizontal would require you to retest.

Running further tests you could start a 44.7 and work your way up in .3gn increments. STOP when you see / feel pressure signs

Testing, keep everything else the same, if you change more then 1 thing at a time you won't be able to determine which worked or DIDN"T to change the group. Once you have found the charge weight then move on to seating depth test.

Seating test is with 3 shots, but you can bail after 2 if they aren't close enough... At 100 yards your bullets should be touching or close if separated horizontally
Latitude can be given for the type of setup.

Bring your seating press and calipers to you location, adjust the bullets as needed adjusting in .003 increments.

Cheers
Trevor
 
kthomas said:
Besides the fact that the worlds leading ballistician says that positive compensation is not really a real effect, not with the quality of todays rifles and free floating barrels, ladders such as the ones you are shooting (which are a form of positive compensation loading), seem to be confusing as hell for people.

I've seen a lot of people chase their tails on CGN with these kind of ladders, trying to read the tea leaves to figure out what the best load is.

My personal suggestion, is to use a decent chronograph to develop a load with the charge weight that gives good ES/SD, and from there testing the bullet seating depth to optimize precision. This can easily be done at 100 yards, and if done properly, will give you a good shooting load from 100 yards to 1,000+.
Click to expand...

Do this and you're done.
 
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