Load development is a critical pathway that leads to “great things” for those of us that are obsessed with precision and accuracy. What’s difficult about load development is how time consuming it can be. Variables include brand of brass, powder type, powder charge, primer type, bullet type, bullet seating depth, and more. If you multiply the possible combinations (even with simplifications) – it’s staggering how “far and wide” you can go to find the perfect load for your rifle.
And that’s where strategy comes in! If you can glean data from fellow shooters and manufacturers, you’ll “fast track” to great results. But there’s still the need to manipulate multiple variables to “hone in on” the perfect load. In this article, I’ll be sharing my strategy and process to find the “perfect load” for the 6 Dasher rifle I just built.
Starting with Quality and Precision
For this load development story, I’m not compromising on quality or precision for anything involved in the project. I’m a believer that the bore and the bullets make the most difference for accuracy and precision, and then there are other factors like ammunition consistency, arriving at the optimal load (this article!), and more. I’ve covered the “budget precision angle” as well, if you’d like to read/watch those stories you can check out one of my related content series HERE. This time, it’s time for top of the line!
You’ll want to check out the rifle build story I put together covering how I put this rifle together:
The Ultimate Cheat Sheet: What the Pros Use
I started my quest for the ultimate 6 Dasher load by reading the following article written by Cal Zant:
In this article, I was able to read about what PRS competitors are using for their loads- what bullets, what powders, and even what charge weights arranged in order of bullet weight! This was a wealth of information that helped me “hone in on” the load development components I would use, and activities I would perform.
6 Dasher Components
Based on the “What the Pros Use” article, and input from Alpha Munitions + Friends, I decided to focus on the following for this first round of load development:
- Alpha Munitions 6 Dasher Brass – the best off-the-shelf option for 6 Dasher
- Hodgdon Varget powder (why mess with success, that so many have had with Dasher and Varget!)
- CCI BR4 primers (bench rest)
- Berger 105 grain Hybrid Target bullets (have won many matches)
- Berger 109 grain Long Range Hybrid Target bullets (new, and with higher BC)
For these loads, I used the following tools:
- Forster Co-Ax press with Inline Fabrication Ultramount
- Forster 6 Dasher custom-honed full-length sizing die
- Forster 6 Dasher Ultra Micrometer Seater
- L.E. Wilson 6mm Wilson Expanding Mandrel Die (see THIS STORY I just published)
- Autotrickler V3 powder dispensing system with A&D FX-120i precision lab scale
- LEE Auto Bench Prime bench priming tool
Berger 109 Grain Long Range Hybrid Target Load Development
I decided to start with the Berger 109 grain bullets because I couldn’t wait to see how they would do!
Disclaimer: Use load data at your own risk. Ultimate Reloader is not responsible for errors in load data on this website. Always cross-reference load data with manufacturer’s published data.
For each of these load development exercises, I started with a 10-shot string looking for speed nodes, and followed that up with OCW-type accuracy testing. See THIS ARTICLE for more detail.
For the Berger 109 grain bullets, the 10 shot ladder looked as follows: (click/tap to enlarge)
All of the shots for the ladder test fell within 0.656″ which was a great indicator of things to come:
Focusing on the nodes at 32.0 grains and 32.6 grains, I got some good results when shooting groups at the 32.0 grain charge for these loads:
Above, we have 4 shots that went into ~0.100″ (consecutively), and the 5th shot was a flyer (taking the group size to ~0.450″), not sure why.
Before moving on to the 105 grain bullets, I decided to try some 1x reloads with the same load recipe:
The same load was used for both of these groups, and even with new brass, I saw SD numbers as low as 2.2 FPS! Here’s the data:
At this point I concluded that we had a great load at 32.0 grains of Varget behind the Berger 109 grain bullet. But then came the Berger 105 testing!
Berger 105 Grain Hybrid Target Load Development
I had a good feeling that the Berger 105 grain Hybrid Target bullets would perform well, and I wasn’t disappointed! I started with the following ladder test:
As you can see, the charges start and finish a touch heavier compared to the Berger 109 grain bullets (as you’d expect). Again, I identified two nodes: one at 32.1 grains, and one at 32.6 grains. Here’s what the target looked like for these 10 shots:
Now things were really getting interesting. The first 9 shots went into a group measuring 0.427″ – that’s amazingly consistent! That told me two things:
- This rifle is GREAT
- The bore, chamber, and bullet like each other
I wasn’t bothered by the 10th shot landing out of the main group- that could be a bad barrel harmonic or who knows what. What I did know is that I had a wide range of powder charges to work with that looked like they would be very forgiving.
I couldn’t wait to see how the groups would shoot! It turned out that the winner at 32.2 grains:
What I didn’t have yet was a super-tight group *and* a single-digit SD. Did we look over anything on the chart? Yes we did.
The Lost Node
After looking at the 10 shot ladder graph again, I spotted another promising node at 32.4 grains of Varget:
So I decided to shoot that load, and what do you know, it SHOOTS! In fact, 5 shots went into about 0.090″!
Later, I shot 5 shots over the Magnetospeed V3, and observed a single-digit SD for velocity (8.1 FPS). At this point, things went from “great” to “super”. Keep in mind- this is with new brass. What an accomplishment.
Next, I’ll be taking things out to 400, 600, and 1000 yards. The real measure of these two bullets (Berger 105 and Berger 109) is how they will perform at these greater distances. Will the 109 outperform the 105 with its higher BC value? Will the accuracy look different between 100 yards an 1000 yards? (this happens frequently). We’ll have to see!
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