Load Development (Part 2 of 2)

LoadDevGraphIn part 1 of our two part series on load development, we were presented with an approach which we believe is objective and fact based, and corroborates some of the things that we have observed during our own load development. In part 2 we leveraged this methodology to evaluate the following loads:

  • 123 Lapua Scenar with H4350 powder. This is our practice load and given our familiarity with it, we worked up loads in .2 grain increments above and below our regular load of 42 grains.
  • 123 Lapua Scenar with Varget powder. Another shooter was reporting excellent results with 38 grains so we had a good idea of where to start. However, his rifle was from a different gunsmith using a different barrel so we decided to explore a wider area in .3 grain increments.
  • 139 Scenar with H4350 powder. We didn’t have any data to start with, but our gunsmith reported that 39.6 grains with Berger 140 Hybrids worked well. We decided to explore loads above and below 39.6 grains in .2 grain increments.

It’s important to note than when we were exploring loads toward the higher end, we were constantly monitoring for pressure signs. As soon as pressure signs are encountered it is best to stop and not fire loads with a higher charge weight. You are better off pulling those rounds and reusing the components.

HornadyTool

Hornady O.A.L. tool in use

The first step (Phase 1 / Step 1) involved determining the cartridge overall length for the chamber. We used the Hornady OAL Gauge with a cartridge case provided by our gunsmith R-Bros rifles. Hornady provides cartridge cases in various calibers but not the 6.5×47 Lapua. Even in situations where Hornady provides a cartridge case for use with the tool, it is highly recommended that you get a case from your gunsmith that has been fired in a chamber using the same reamer. If you are handy, you could make your own using a fired case – you just need to thread the case so it will screw onto the tool. Be sure to watch the video for tips about using the tool that are best conveyed visually. Long story short, you want to use the tool gently as it’s easy to jam the bullets into the lands resulting in inconsistent readings.

If you don’t have the Hornady OAL Gauge you can accomplish the same thing by loading a number of cartridges in .0025 – .005″ increments and coloring the bullets with a marker. You can then chamber the bullets and determine which length engages the lands. While this method works, we highly recommend getting the Hornady OAL Gauge as you will find many uses for it. For example, this tool really helps when you chase the lands as the barrel erodes.

Since we are using VLD bullets, we like the bullets to just touch the lands, but we don’t want them jammed into the lands where a bullet will be left in the barrel if a live round has to be ejected. The Scenars can be jumped, but they also work great touching the lands so that’s how we load them. If you like to jump your bullets, start .020″ from the lands.

EdShootingNext came shooting the groups (Phase 2 / Step 1) and gathering chronograph data (Phase 2 / Step 2). It is very helpful to have a partner record the chronograph results and note any anomalies. As shown in the video, we shoot all rounds of a particular charge weight at one target being careful not to break position. However, we do randomize the shooting order of the charge weights. This is different than the round robin method advocated in the OCW method – the round robin method can introduce a lot of human error since it’s essentially a slow motion dot drill. Few people can shoot a perfect dot drill even with unlimited time. There is nothing wrong with shooting in a round robin fashion provided you are confident in your abilities and can completely rebuild your position between each target.

In our testing, there was one group that was much larger than the others due to some rear bag issues we were having. Had we been utilizing the round robin method this error would have been spread out across multiple groups. I could see arguments going both ways – some saying it’s better to spread the error out while others would advocate containing the error and re-shooting a group if it was an anomaly. We be interested in the opinions of our audience on this.

The next step (Phase 3 / Step 1) was the analysis of our groups and chronograph data. The worst group was still under 1 MOA and most groups were well under .5 MOA. In other words, there were no “bad” loads with the 6.5×47 as far as group size is concerned and we can see why this is such an attractive cartridge. However, some loads clearly have lower velocity spreads than other loads and these differences will show up at the longer ranges that we shoot at. As such, it makes sense to use the loads with the lowest velocity spreads. Here’s what we found out (please open up the  Load Analysis Spreadsheet as you read along):

  • 123 Lapua Scenar with H4350 powder. We confirmed that 42 grains of H4350 is the optimal load for our rifles. We saw similar results across two different rifles using different lots of powder.
  • 123 Lapua Scenar with Varget powder. While we were hoping for an optimal load at 3000 fps, we noticed the slightest amount of bolt stickiness at that velocity. The next step down (37.7 grains) turned out to be the optimal load as far as the chronograph data was concerned so that’s what we’ll roll with when using Varget and 123 Scenars. One thing that really stood out was the consistency of the Varget / 123 Scenar combination across charge weights. We also like the fact that loads using Varget are not compressed. Varget might be the ticket for lighter bullets in the 6.5×47 Lapua.
  • 139 Scenar with H4350 powder. The optimal load yielded the lowest SD (1.6 fps) and ES (4 fps) of the day. 39.8 grains of H4350 will yield a velocity of 2788 – pretty respectable. However there is a pronounced flat spot in the velocity curve so 39.7 grains might be a good choice as it sits in the middle of the flat spot.

Here are some additional thoughts and we welcome opinions from the audience on this:

  • It’s easy to look at the results and agonize whether you should add or subtract .1 grain from the load (as was the case with the 139 Scenar). To provide some context, lot to lot variations in powder can be pretty significant so even if you dial in a load with that level of precision, you’re going to start over again with each lot of powder.
  • With experience, and in consultation with your gunsmith, we believe you can identify a load that is an all around performer day in and day out in your rifle. We have such a load that was recommended by our gunsmith (see below). Ed ran into one lot of powder that was a little hot (he was getting a sticky bolt) so he backed down half a grain so he would get the same velocity as the previous lot of powder. It still shot lights out. The next lot of powder was cooler so he went back to the original load to maintain the same velocity. Again, it shot bugholes. It appears as if the optimal loads for a given combination of components fall into certain velocity ranges – you hear this talked about in the context of optimal barrel time. From our load development, it appears that 123 Scenars going at 2950 – 3000 fps shoot really well. The results from the 139 Scenar suggest that bullets in the 139-142 grain weight class like to cruise along at or near 2,800 fps. It’s really interesting to see patterns like this emerge as it adds a degree of predictability to load development.

Some of viewers may have noticed two very small 5 shot groups labelled 130 VLD. These were our two control groups – one shot before the start of the session and one shot after. As you can see from those groups, our 6.5×47 Lapua match load consisting of Berger 130 VLDs with 42.2 grains of H4350 and CCI 450 primers shoots lights out.

130VLDStart130VLDFinish

 

 

 

 

 

In conclusion, we will adopt the approach outlined in part 1 going forward. It seems to combine the best elements of the OCW method while recognizing the need to minimize velocity variations. There might be a machine rest in our future in which case we can minimize the human element and stop guessing whether a flyer was caused by the shooter or the load.

Finally, a number of you have asked for the spreadsheet we used to track the data. Here it is: Load Analysis Spreadsheet We will be working on instructions that will be provided with a template spreadsheet so you can modify for your particular situation.

Thanks again to the members of our audience who provide encouragement and feedback.

Latest Comments
  1. brad

    Having build my first .260 bolt action and am new to reloading I really appreciate your articles. Question: Have you done any load development with the new Berger 130gr AR bullets?

    • 65guys

      Hi Brad,

      Thanks for the kind words. I expect to have some Berger 130 AR bullets in my hands tomorrow and plan to work up some loads with the 6.5×47. Since you are shooting .260, you might want to consider the 140 Hybrids too – at least that’s what the other folks are shooting. I have a .260 and plan to see what sort of numbers I can get with both bullets.

      Regards,

      Ed

      • brad

        Thanks for the rep[y. I have some 140’s and just received a box of the AR 130’s. I wanted to experiment with bullets in my 10 round magazine with the .260. I am also in the building stages of a AR-6.5 creedmore.

        • 65guys

          Hi,

          If you’re using an AI mag, you should do fine with either bullet. Only if you have a really deep throat you might have an issue with the single stack mags and the 140. Anyway, please keep us updated on your progress.

          Regards,

          Ed

  2. Greg Z

    Thanks, Ed and Steve, for another good show of your techniques. What I still can’t figure out is how you get such a low SD. What can you identify as key factors? Only certain powders, neck tension, % case fill, primer experimentation, etc? I have not tried seating to lands for .308 due to mag issues. Different jump seating depths seem to make no difference in SD. If I get an SD @ 10, that’s remarkable, ave load 15-20. Tried double checking Chargemaster with Gempro, but the Chargemaster is fairly dead on. .

    • 65guys

      Hi Greg,

      I don’t believe it’s any one item, rather it’s the cumulative effect of optimizing reloading practices and hunting around for the load with the best SD. We really started getting SDs in the low single digits when we moved to the 6.5×47 Lapua. We also had the benefit of starting with a known good load provided by our gunsmith. Before that, we used to be happy with SDs in the teens. We also believe the MagnetoSpeed is more accurate than shooting over a tripod mounted chronograph (but we’re not going to argue with somebody who uses an Oehler).

      But sometimes a single factor can have a significant affect on SD. If you look at the results we got with H4350 and the 123 Scenars, moving away from the optimal load increased SD and ES. On the other hand, Varget seemed to give great SD and ES numbers no matter what the load. Again, the mixture of components has an impact.

      It’s been a while since I’ve shot my .308 but I’m going to start doing some workups as I’m getting a new AI AT rifle. I’m curious to see if I’ll get the same low SD and ES that we’ve gotten with the 6.5×47. We’ll certainly keep our viewers posted.

      Thanks again for watching and reading.

      Regards,

      Ed

  3. Phil in AZ

    Hi, Guys. I enjoyed the videos, but have a question concerning your measurement of COAL from the ogive. I understand the whole distance to lands measurement and I use the same Hornady set up but wondered why you use the rim to ogive measurement when you could use rim to tip measurement for COAL. Once you figure OAL to where the bullet is just touching the lands then back off .020″ for starting optimal jump, what difference, in your opinion, does it make if you measure to the tip or the ogive? Subtracting .020 from the ogive measurement or from the tip measurement both equal the same length cartridge. All SAAMI specs are rim to tip, and you are limited by rim to tip COAL because of magazine dimensions. Why add another dimension that can be measured another way and more in keeping with published methodology and practical use in your rifle?
    Cheers,
    Phil

    • 65guys

      Phil,

      That is an excellent question. The method you describe is what we used prior to obtaining the Hornady tool. The biggest problem with measuring from the tip of the bullet is the lack of consistency especially with open tipped bullets. Sometimes the difference can be as much as 10 thousands or more. If you trim the meplats, you could get more consistent measurements but very few shooters trim meplats.

      Hopefully my answer helps. Thanks for watching!

      Regards,

      Ed

      • Phil in AZ

        Thanks, Ed. I did go back and read through some of my books last night and found in the front of the Berger loading manual Brian Litz’s article (pg 148) about measuring CBTO (cartridge base to ogive) and its merits and demerits. His reasoning included your answer along with several others. My big takeaway was that measuring exact CBTO is damn near impossible as measuring devices are somewhat inconsistent and bullets vary through lots. He did comment that using the Hornady gauge, while somewhat flawed, is a decent method of measuring CBTO.

  4. Monte Milanuk

    Just curious… have you ever tried replicating a given experiment on successive range trips? Given the +/- tolerances involved in powder, primers and the chronograph I would wonder if the node or ‘sweet spot’ might shift a little (or a lot) from session to session.

    • 65guys

      Hi Monte,

      I’ve thought about that. We were able to do that with our 123gr Scenar loads and H4350. Using different rifles on different range trips we obtained similar results.

      Ideally we would run each test multiple times, but time and other commitments tend to be the limiting factor.

      Regards,

      Ed

    • 65guys

      Hi,

      When you find a good accuracy node it compensates for those variations. In our video, we discovered that our accuracy node for 123 Scenars was the same across different rifles on different dates. I have noticed some significant lot to lot variations with H4350, but so long as I’m getting low SDs when I chronograph I don’t feel compelled to do a complete load workup.

      Regards,

      Ed

  5. Chad Herring

    Hey guys… I am getting ready to do some load development on a 260 Remington with 123 Lapua Scenars and I want to utilize the spreadsheet but I can’t figure out how to adjust the bottom axis of the graph to show a wider range of charge weights. I am going to try 42.2 to 43.8 in .2 grain increments. Thanks for any suggestions.

  6. Pete

    Hi guys,

    Love the Videos. Any chance of getting a copy of the spreadsheet you use?

    keep up the great work

    • Christian U.K.

      I would like to have such a copy my self. Would be great if you are willing Share. Thank you 🙂

    • 65guys

      Hi,

      We posted as part of this article: http://www.65guys.com/developing-a-practice-load/

      Scroll down to the bottom for the link.

      Thanks for your interest!

      Regards,

      Ed

      • Christian U.K.

        Great, thank’s a lot!

  7. brad

    Great article with good information. Question in regards to OAL gauge: I am new to reloading, that being said, I have measured seven different bullets at least 10 times each.difference in measurements are from .000 to .006 with each projectile. I cannot seem to get the same measurement on a consistent basis.

    • 65guys

      Hi Brad,

      There is a bit of a technique to getting consistent measurements with the gauge. Please text me at (916) 801-1448 regarding a good time to talk – it’s more than I can write.

      Regards,

      Ed

  8. Dan

    Have you guys completed a template spreadsheet with instructions for the load workups you performed above? I’ve downloaded the one’s listed in the article but can’t seem to get it to graph the data like you have demonstrated.

    Thanks for the helpful information

    • 65guys

      Hi Dan,

      Thanks so much for watching. While we are happy to supply the spreadsheet, it takes some advanced skills to get it to work. Steve is the Excel jock and had to patiently explain to me. We’ll put it on our To Do list to get a writeup or video together regarding the use of the spreadsheet. As you can imagine, things have been super busy and we have to prioritize this along with a bunch of other stuff.

      Regards,

      Ed

  9. Rossco

    G’Day Guy’s
    Very interesting couple of video’s it’s pretty much the way I load develop as well, looking for the most consistant velocity then tune by bullet seating. I have also found that AR2208 or as you guys call it Varget in most cases be the most consistant and this goes with most Australian made powders.
    Cheers
    Rossco

    • 65guys

      Glad you enjoyed it Rossco. Thanks for watching.

      Ed

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