6.5 Creedmoor Load Data

Building load data for your precision rifle is critical to get the recipe your rifle loves. You can just randomly pick loads and you may get lucky, but 90% of the time you can get a better load developed.

The key to getting the load your rifle likes is by taking velocity readings for multiple loads and comparing them. I use a Magnetospeed Chronograph to get data. You can use the typical chronograph with skyscreens or the Doppler radar type. I have a sky-screen version and just prefer the Magnetospeed when at the range as I don't need to go beyond the bench to set it up. Lighting is also not critical as the Magnetospeed doesn't required light to work. I have actually shot in the dark in a pinch to get velocity data and that part is great.

Once set-up, you should take five shot groups to collect data. Ten would be better, but five will get you what you need and you don't heat the barrel up as much. Take careful notes when collecting data to record each shot's velocity and where it landed on the target. Once you have the velocity data you can calculate the numbers to get MAX. MIN, Average, Standard Deviation and Extreme Spread. Standard Deviation and Extreme Spread are what you are looking for to get a consistent load. You can get good results out some loads with high Standard Deviation or Extreme Spread, but if you are shooting long distance, you really want the speed of the bullet to be consistent for repeated accuracy.

I started load development in my 6.5 Creedmoor with a load consisting of 40.5 gr of IMR 4350 pushing a 140 gr Nosler RDF bullet. The load was actually pretty accurate but the Extreme Spread was between 75-85 FPS. I knew I could get it better and hopefully would pick up some speed to help keep the trajectory flatter. I decided to start loading up 40 rounds with eight different loads. I increased the charge weight of the powder in .2-.3 gr increments. I ended up with five rounds each in the following weights : 40.8, 41.0, 41.2, 41.5, 41.7, 41.9, 42.2, 42.5. Each load was weighed on my RCBS Chargemaster scale/powder measure. I shot five rounds of my original 40.5 gr load to foul the barrel and to get some heat into it as well. Then I would shoot strings of five and collect data. I also watched the cases and primers for signs of pressure as I was venturing out of reloading manual ranges. After a full day of shooting, I found that I had good data and a pretty good idea on how the bullets were grouping.

I found three loads that had fairly low Standard Deviation and Extreme Spread. I will now capitalize on the load with 41.5 gr of powder. I can now perfect the bullet seating depth to help tighten up the groups. I am already sub-MOA and would love to consistently have one hole groups. You can see the S-D comes from high to low, then starts climbing back up. The lowest area is where you want to zero in on and load to that data.

Here is the data as well as a representation of the targets from information I recorded at the range.

As you can see in the image below. The grouping was good. I am using the bottom left diamond as the aim point. I am zero'd for 300 yards and shoot about 3.5" high at 100 yards. I am mostly concerned with the grouping and velocity now. I will adjust the scope in future sessions when I have the Magnetospeed removed. I was also shooting suppressed for the first time on this rifle. It is definitely the way to go!!!!