10 Round Load Development Ladder Test

Identifying a consistent and accurate load for your precision rifle while improving the overall efficiency of the load development process is a laudable goal. The 6.5 Guys met with Scott Satterlee to discuss and explore a technique he calls the “10 Round Load Development Ladder Test”. This is a load development approach he has refined to quickly identify accuracy nodes with only 10 rounds. Additional cartridges are then loaded to test and confirm these accuracy nodes. Scott’s approach really interested us as load development has traditionally been a time intensive and laborious process.

A lot of folks ask us if Scott’s methods are a replacement for OCW. When asked that question, Scott responds that his method uses a chronograph to get to the same answer as OCW. Prior to the availability of the extremely portable and accurate Magnetospeed, shooting groups as prescribed by the OCW method was the most practical way to arrive at an optimal load. Long story short, if you want to use the OCW method as promulgated by Dan Newberry there is absolutely nothing wrong with it. However, Scott believes his method is more efficient and arrives at the correct answer faster.

The following quote from Scott summarizes a key observation with load development, “Im not sure it is optimal charge weight at all but optimal velocity for the bullet weight that determines barrel harmonics. The reason I say this is because I can get the exact same great results in a velocity node using seven different powders. As long as I keep the bullet going the same velocity from powder to powder I get the same result. Powder charge may be slightly different but as long as I’m in the velocity happy place for that bullet and my cartridge, powder is secondary.

Scott’s method is predicated on the shooter having their reloading techniques dialed in. After the release of the video, we had a number of viewers ask us what Scott does to perfect his reloading technique. We can tell you from personal experience that we have adopted many of Scott’s techniques and they work:

  • Brass makes a big difference. Buy good brass and be done with it.
  • Get a good chronograph. From a convenience and accuracy standpoint, the Magnetospeed is hard to beat.
  • Sort your brass by lot and the number of times they have been fired. We can’t tell you how many inquiries we get from folks who purchase mixed lots of brass at the local outdoor store and wonder why they can’t find a good load.
  • Annealing works. There was an experiment done by a reputable company and super smart guys, but the experiment was too limited to replicate high volume shooters. Take a look at our article on the AMP annealer where we discuss this.
  • Powder weight is pretty important. Measure every single charge unless you are reloading in volume for a gas gun or pistol. A lot of folks use the RCBS Chargemaster and certain modifications can be made to really dial them in. This will be the subject of a future article.
  • Find a load length that gets your bullets off the lands. A load that is jammed into the lands will not have durability and you will have to readjust them frequently. VLD bullets can be jump tolerant and extremely accurate well off the lands. The following article from Berger Bullets confirms this.
  • Remove primers as a separate step using a dedicated die such as the Lee Universal Decapper. We’ve conducted experiments where using the sizing die to decap increases runout.
  • Use a mandrel instead of an expander ball. We’ve noticed less runout and lower SDs by doing this. Get a carbide mandrel so you can remove any burrs or imperfections after you remove the sizing lube from the brass. A mandrel also helps in conditioning the necks on virgin brass and avoids the need to full length size virgin brass.
  • Pay attention to primer seating. Seat the primer until the anvil touches the bottom of the primer pocket and go ever so slightly further (.001″) to pre-stress the priming compound. This requires a refined sense of feel that can take some time to develop. We’ve encountered shooters with dud rounds who claim “I’ve got some bad primers.” Almost without exception, they are not seating their primers deep enough.
  • If running a compressed load, settle your powder. Check out our article on bullet seating.

Here’s a summary of Scott’s “10 round” technique as described by him:

“I start 1.5 grains below my max load and load 10 shells ascending by .2 gr. So for the Swedemoor, 50.0, .2, .4, .6, .8, 51.0, .2, .4, .6, .8, 52.0
Then I will shoot these over the chronograph and look for the nodes. A node will be a velocity flat spot where .4-.8 gr of powder doesn’t move the speedometer much. This example with Reloader 26 in my 6.5 Addiction with 140 RDFs, the flat spot is between 51.2 and 51.8 grains -velocity went from 3025-3033 fps. So, .8 grains of powder added a total of 8 fps. Therefore, the middle of my node is 51.5 grains.

Next I then load up 5 of the 51.5 grain load and shoot them over the chronograph and the extreme spread was 5 FPS. I have repeated this with H100V, H4350, 4831, 1000, Retumbo, RE 17,19, 22, 23, 26, wiN 760, 780, VV 160, 170, 560, 570 IMR 4451, 4955, 7828 and 7977. With all of these powders, 3020-3035 fps was an accuracy node without regard to the powder type.

Once I find the velocity node I load in the middle of it then fiddle with COAL until it shoots tiny groups with low low extreme spreads. You can have an accurate load at 100 yards that will not shoot past 600 yards because you have a high extreme spread. For me any extreme spread that is over 25 FPS is unacceptable no matter how small the group is at 100 yards. Even if I had a load that shot .1 moa at 100 yard yet had an ES of 30, I wouldn’t use that load for a match. I would take a .3 moa load that had a sub 10 fps extreme spread any day of the week because the load will not start to spread vertically past 600.”

Editor: Ed Mobley (ed@65guys.com)

Copyright 6.5 Guys LLC

Latest Comments
  1. R C Jones

    Not to split hairs … but for the example you gave of loading by .2 grain increments … I count 11 rounds if you’re including 50.0 and 52.0. It’s ten steps of incremental change, but actually 11 loads. Regardless, I get the core idea of what is being done. Also, I appreciate your emphasis on evaluating distance, velocity and accuracy (as it relates to ES). Too often, shooters will look only at velocity … which by itself has nothing to do with accuracy.

  2. Peter Wierenga

    I’m working on Scott’s system and I’m VERY impressed. I’m reading for the “COAL fine-tuning” stage. More detail on that? Start where in relation to the lands? What size increments in thousandths? How many rounds per increment? Shot at what distance (is 100 yards okay)?

    • 65guys

      Hi – just went through this with our .308 load development. Unless we’re shooting a VLD type bullet, we start at .020″ off the lands. We we’re playing around with the Nosler 175 RDF bullets and upon recommendation from Nosler went to .050″ which seemed to tighten up the groups.

      100 yard groups don’t tell you much. On several occasions, and as illustrated in the video, you can shoot one inch groups with 2 grains variance in powder weight. If you are going to shoot groups, consider 200 yards the minimum. Also keep in mind that the human error associated with shooting groups can send you in circles unless you really have things dialed in. For those reasons, we focus more on the chronograph results because that will dictate your accuracy at long range.

  3. Peter Wierenga

    Notify me if follow up posts..l

    • 65guys

      Hi – we just replied to a number of posts…thanks for your interest.

  4. Orie Wall

    I tired this method and my results weren’t too good, And Im looking for advice to improve my process. I was using 73gr ELD-M and cfe223 powder. I shot from 22.8 to 24.8 gr powder in .2 increments and found a couple of very narrow nodes 4 fps between 24.6 and 24.8. So I loaded 10 rounds of 24.7 and shot to groups my ES was 36 and 40 for the 2 groups. The groups were +4moa at 100yd with magnerospeed attached. Prevoius experience with other grain bullets I should only see the groups high on the target and maybe 1.5 moa. Im suspecting something is wrong with my thinking or process, likely both! Any theories or things I should look at.

    • 65guys

      Hi Orie – we noticed something similar when doing load development with our .223. Using CCI Small Rifle Magnum primers we had no problem keeping SD under 10 fps. On a lark, we decided to see if the Remington 7-1/2 benchrest primers would decrease SD. Instead, SD shot up to 30 FPS!!!! You would think a benchrest primer would decrease SD but they didn’t in our case. Assuming you are weighing each charge and your scale is accurate, see if you have better luck changing primers. Best of luck!

    • Matthew

      Just go with the 75 grn Hornady Hpbt Varget 24.5 grns problems solved. Assuming your shooting a ar-15 with a 1-7 twist

  5. dnellans

    decided to give this method a try. loaded up 20 rounds 2×10 in .2 increments. 10 extra rounds over what you guys suggest to test repeatability (excel is judge and executioner)

    will chrono in the morning with magnetospeed sporter. not shooting for groups in any way (nonpics)

    rl-16 with 147gr eldm’s coming out of factory RPR…

    • 65guys

      Please share your results…

      • dnellans

        i gave this a shot and did 2 grains worth of .2 variance. 10 shots total. found that not only was there no obvious flat spots the results were noisy enough that trying to spot a flat spot would be near impossible. decided to give it another chance and shot a second string with the same general trend but any individual grain count might be off by as much as 10fps between the two shots. so added a -third- string, in for a penny in for a pound at this point, and only with three shots at each .2 increment did some trend start becoming obvious. after shooting about 50 more in groups of 5 to look at the SD/ES and mean while dialing in seating depth etc. i think i’ve found my load.

        long story short – unless you’re confident that your SD and more importantly ES across a 10 shot string is less than the 10fps difference you might see when going from 43.5 to 43.7 grains (for example). then there is almost no way you can trust the results of one shot at each charge level. and how do you know what your ES and SD look like without shooting at least 5 of the same load? not very many guys can keep ES in the single digits even after trying different primers, etc. Assuming a new barrel and load you’ve never shot that you’re trying to work up, thinking you’re in single digit ES is probably lunacy even if your technique on other loads is dead nuts.

        In hindsight and plenty of excel plotting behind me, I think the math and number of shots required for going off of fps and looking for a flat spot simply isn’t statistically valid for 99.99% of people out there.

        if you start shooting 3 or 5 st each charge level to have confidence, then it starts looking suspiciously like a OCW test with the addition of chronograph data to confirm velocity grouping not just accuracy on paper. i don’t see any way around needing 50-100 shots to have confidence in both chargeweight and seating depth even if you’re an “above average” reloader and can manage single digit SD’s and an ES OF 15 for a 5 shot string.

        The math on the 10 shot ladder teqhnique just doesn’t add up.

        • 65guys

          Thanks for sharing your experience. As we mentioned in the video, this is an advanced technique. If you don’t have everything dialed in ranging from powder dispensing, neck tension, etc. things can get lost in the noise. Before I went to the 10 round technique, I started to shoot only three shots at each load – that’s the “hybrid” technique I mention at the close of the video. I then moved to two and as I gained my confidence moved to 1 shot. Regarding OCW, there is nothing wrong with that technique and if you are confident in your ability to shoot groups consistently you should use what works. Personally, I find myself introducing too much human error particularly with higher recoiling rounds so it’s nice to use the chronograph results as a sanity check.

          • dnellans

            Shooting groups is certainly tough too, especially when you start talking about trying to get down below .5 MOA (at least for me).

            At 100 yards, if you can’t manage to shoot .5 MOA all day every day off your normal biopod and bag, then trying to get your ES down to ~13 (where you’d have 1MOA of vertical dispersion at 1k yards), you’re probably better off trying to improve your trigger control and group shooting than reducing your SD and ES.

            Just like .1 MOA 100 yard groups are worthless if you have an SD or ES in the 50’s (2+ MOA of dispersion at 1k yards), having a ES of 5 doesn’t do squat if you can’t manage to shoot those .1 MOA groups.

            There is probably some ratio of group size to SD/ES you could calculate that shows one versus the other is your limiting factor. You guys should convince Cal over at precisionrifleblog to figure it out with WEZ and do a joint article!

            , then an ES of ~13 is going to give you ~ 1MOA of vertical dispersion regardless of how well you’re shooting. If your group shooting isn’t up to the task

          • 65guys

            You bring up an excellent point – when you are shooting off a pile of rocks or a barricade with a 1MOA wobble it really brings things into perspective. Personally, I (Ed) have shot enough to know that if my SDs are not in the single digits, there are opportunities for improvement. These days I typically get around 5 fps SD with most cartridges. Maybe when I get a better powder scale I can bring that number down. From a grouping perspective, I have a goal of getting consistent .5 – .75 MOA groups at 100 yards shooting from a bipod. With my .223 trainer I can literally shoot the staples on my target at 100 yards with mixed headstamp ammo and powder charges thrown with a Dillon powder measure. With the higher recoiling .308 I’m not nearly as accurate with even the most meticulously loaded ammo. The ability to manage recoil has a big impact on accuracy based on my experience.

            When I first got into this game, I’d be thrilled with a 1 MOA group from any rifle but my standards have evolved as I gain more experience. If I can find a load with single digit SDs and the ability to shoot sub MOA groups I turn my attention elsewhere: positional stability, wind reading, etc. It is certainly a journey….

          • dnellans

            only took me 120 shots to get there but… 0.5 moa load – check. single digit SD – check. good dope shooting out to 1k yards prone or from the bench -check.

            1 moa wobble off the barricade – not a chance in hell! i’d be happy to keep it a -just- 2 most of the time from my limited practice 🙂

            can’t wait for it all to be perfect though… off to my first PRS club match in the morning! thanks for all you do guys, definitely pushed me over the edge to register

            reading/watching

          • 65guys

            Best of luck at your first match! Sounds like you have things dialed in!

  6. Devin

    Just used this technique on my 7mm rem mag. 10 fps spread and pretty dialed in on my pet load. All in about 30 rounds thanks to these guys.

    • 65guys

      Glad it worked out for you!

  7. dave christmas

    I have been having issues with my 308. I “seem” to get crap groups with low SD or good groups with high SD’s. I have a decent group going with a SD of 12.8. When I change the bullet seating depth as you suggest, the velocity changes.
    Now what?

    • 65guys

      Hi Dave,
      We’ve been there. A couple of questions:

      1) At what distance are you shooting your groups?
      2) How repeatable are your groups? For a load that groups well, can you get the result time and time again? We just ask, because shooting groups can be very error prone unless you really have things dialed in.

      We would suggest that you focus on the load with the lowest SD because the loads with a high SD will not perform well at distance no matter how well they do at 100 yards.

      • dave christmas

        100 yards is all I have at my local club. I will go back and look at my results again. Based on this conversation I will change my tactics and see what I can do this weekend. I will update you on my results. Thanks so much.
        Dave

      • dave christmas

        So, finally I am back at it. Ran out of primers F210M and cant find them locally so I had to change after more than 20 years of using nothing but the Federal. Then I couldn’t find more powered for the load I was working on.
        Perfect time for this process as I am basically starting from scratch. So, |Berger 155.5, Varget, Remington second firing brass with S & B primers. Found a good wright up on these primers so I am giving them a try.
        So, bright and sunny, lite wind, 26C. (Canada EH) 10 rounds loaded starting at 44.2 grains up 0.2 increments to 46.0. Shot low to high with fouled barrel. Results in order, where….
        2720.2
        2718.3
        2736.0
        2752.9
        2769.1
        2762.4
        2781.6
        2798.2
        2808.0
        2829.9
        Yes they are in the right order and yes I was very carefull to shoot them in the right order by load. Excuse me but WTF do you do with that? BTW, when I was done this I shot one more group with the same primers and brass. Reloader 15 and Hornady 168 M. Average speed 2689.5, extreme spread 17.1, MAD 5.0 SD 6.6.
        Suggestions please?

        • dnellans

          haha – i felt like I was in the exact same boat as you. all i really learned was that more powder equals more FPS. wish I could tell you that i thought this technique worked but…

        • 65guys

          Hi,

          When you go from 2720.2 to 2718.3 and from 2769.1 to 2762.4 Scott calls those “inversions”. Those are areas worth exploring. Since you are shooting Berger 155.5s you may want to explore higher velocities. Assuming a 26″ barrel and a .308, most folks like to get 2900 – 2950 fps. When I (Ed) used to shoot the 155 Scenars in my .308 I found a nice load in the 2950 range. Unfortunately, the 155s are no legal for PRS tactical class. But if I wanted to make the most of the .308 I’d shoot a high BC 155gr bullet.

          As always, watch for pressure signs when working up your loads.

          • dave christmas

            I will be shooting Meaford Ontario September long weekend. I will be shooting the 155.5’s in the tactical division. I just checked the 2017 rules update and I see nothing about shooting a lighter weight bullet for 308. Only a cap of 178 grains with a max of 2800 fps.
            ???????

          • 65guys

            Hi – I just went back to the rule book (https://www.precisionrifleseries.com/static/media/uploads/prs_rules.pdf) and sure enough:

            “7.62 NATO/.308 Winchester has a bullet weight cap of 178 grains and muzzle velocity cannot
            exceed 2,800 fps.”

            Only issue is you’re giving up a lot of ballistic potential by shooting the 155.5 at only 2,800 fps. For those reasons, a lot of folks are running the 175-178 grain bullets at or near 2,800 fps.

          • dave christmas

            Meaford changed gears and placed a 168 grain cap on projectiles for this shoot. I was using the the 178 A-max

          • Dave Christmas

            24″ barrel Kimber Advanced Tactical. Tough getting range time of late. So I picked out 3 spots of interest as you suggested. Results where …
            44.3 grains, 2642 fps SD 8.3
            45.1 grains, 2697 fps SD 8.2
            45.7 grains, 2730 fps SD 5.6
            I have loaded 20 more rounds, 5 each at different lengths to see if one is better. If all goes well I will try these on Sunday.

  8. Mike

    I just watched the video, that’s a real eye opener. It would have been instructional as part of the video, to have seen a few loads at various distances (100, 600, 1000) and see how the preferred load compared to those that might have been less preferred. Next time I am out testing I am going to give this method a try. I also like you hybrid idea of 3 shots per charge; I would do each 3 shot group on separate targets as well.

    • 65guys

      Please share your results. Thanks for watching!

  9. Noah Jessee

    Okay, so I was at a point of working up new loads for 123 and 139 Lapua Scenars using Varget for both, so I decided to give this a try. I was not going for maximum velocity but rather looking for milder velocity since I was using these loads for high power silhouette. Here are some specifics: 6.5 CM, Hornday brass resized using a Lee Collet die, Federal 210 primers. Rem 700 w/bolt lugs lapped, pillar bedded, Criterion sporter barrel. Loaded up 10 rounds of each, 0.2 grain increments bracketing the velocity I was looking for.

    For the 123, I found a spot where the ES between 4 shots was 12 fps and for the 139, a spot where the ES between 3 shots was 13 fps. Using a Magnetospeed for velocity measurement.

    Loaded up 10 rounds of each using the average charge weights from the above flat spots. Chronographed 5 shots of each. For the 123, SD of 6.7, ES of 14. For the 139, SD of 5.2, ES of 13. Shot the other 5 shots of each w/o magnetospeed for accuracy.

    All groups, with or without magnetospeed were 0.75 MOA and I think with adjusting seating depth, it would do better.

    As a side note, the temperature when I shot the first 10 rounds was 53 degrees and 88 degrees when I shot the second 10 rounds. The tested load velocities were within 8 fps of each other.

    I used OCW in the past, but I like this approach way much better! Thanks to you 6.5 Guys and Scott for sharing!

  10. David Smith

    I will be trying this Load development for the first time this week, Had to rebarrel and went with a new cartridge, (6 dasher). I Have 5 days until my next match to find a load an load it. Can’t wait to see what shakes out of it. Might try the Hybrid method as I’m not familiar with this cartridge.

    I was wondering what was a good Seating depth from the lands? I seen your previous post in reference to the Nosler RDF’s. Would you suggest the same .050″ for a sierra 110 Matchking?

    • 65guys

      Hi,

      I’d start with .020″ and shoot your ladder. If your desired load isn’t grouping as you would like, try to seat it out further in .010″ increments (.030″, .040″, .050″ etc.).

      Best of luck!

  11. Duane Madoerin

    Tried this for the first time yesterday. I am doing this by interchanging guns every three shots to keep barrel temps down. The three shot segments are made up of increased powder volume by .2 grain. In other words first shot of three is .4 grain less than third shot. Using a Labradar to record velocities. Numbers are all over the place…nothing consistent. First shot of three may or may not be fastest of three, etc. This is happening with all three guns. Do you think the process of shooting in three shot segments is amplifying cold/warm barrel effects? Thanks, Duane

    • 65guys

      Hi,

      No two guns are the same so changing rifles is most likely the issue. I would use the same rifle – just wait a few minutes to let the barrel cool.

      • Duane Madoerin

        Thanks. What I am trying to do is run a load development for each rifle and the respective powder simultaneously. I thought this would be an efficient way of using the barrel cool time…to develop a load for another rifle. Like what you guys are doing. Keep up the good work.

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