I’ve already done quite a bit up to this point in my load development. At this point I know I want to try to find an accurate load for Berger’s 168gr VLD over Hodgdon’s Retumbo powder and I’m now zeroed in on a very specific range of powder weights that seem to be very tolerant of slight pressure variances. You can see the previous posts for how I got here. My next step is to test 5 shot groups in very granular powder increments. Jump to another step: Part 1: Bullet Selection & Real-World Velocities Part 2: Audette’s Ladder Test Part 3: Optimal Charge Weight Part ...
Read More »7mm Rem Mag Chamber Print
When the 7mm Remington Magnum was originally released, it was met with overwhelming demand. Every rifle manufacturer rushed to offer rifles chambered for the new cartridge, and in the rush some of the chamber dimensions varied slightly from different manufacturers. This variation in the 7mm Rem Mag chamber dimensions has carried on to today, and there is still more differences in the chamber dimensions than for virtually any other rifle cartridge. What’s a chamber print? A “chamber print” is an illustration of the chamber reamer used to cut a rifle’s chamber. It contains all of the key dimensions related to ...
Read More »7mm Rem Mag Load Development Part 3: Optimal Charge Weight
After I identified a promising range of powder weights using Audetter’s ladder test, my next step was to use Dan Newberry’s Optimal Charge Weight (OCW) Method to offset the “scatter node” drawback inherently present in the ladder test. To learn more about that, read this article comparing the OCW method with the ladder test. The OCW method is based on the observation that there are some loads out there (like Federal’s match ammo for the 308) that shoot really well out of just about any rifle. How can one recipe shoot so well out of so many different rifles? Dan Newberry believes accuracy of ...
Read More »7mm Rem Mag Load Development Part 2: Audette’s Ladder Test
The first step in load development for my new custom 7mm Rem Mag started with gathering the real-world velocities I could expect out of three quality long range bullets I was considering. I then used those velocities to compare the ballistic performance between those three bullets, as well felt recoil during the test rounds. I eventually decided to pursure further load development for Berger’s 168gr VLD bullet over Hodgdon Retumbo powder because it struck the right balance for me between the competing characteristics (recoil, barrel wear, flat trajectory, low wind drift, ideal energy for medium sized game, etc). For more ...
Read More »7mm Rem Mag Load Development Part 1: Bullet Selection & Real-World Velocities
The first step in load development for my new 7mm Remington Magnum (with a 27″ barrel) was to get a basic idea for the real-world muzzle velocities I could expect out of a few different high quality, very low drag bullets, so that I could compare them ballistically and decide which to pursure for further load development. I decided to try out the three bullets listed below after reading a great article on 7mm bullets by Nathan Foster. I actually took all of these readings with a BRAND NEW BARREL (some of the first rounds out of it), so they ...
Read More »Creighton Audette’s Ladder Test
Creighton Audette came up with a method for developing precision rifle handloads that has been referred to by many names: Incremental Load Development Method (ILDM) The Ladder Test 20 Round String Method Unfortunately many of Audette’s original articles aren’t very accessible, so I wanted to provide a few resources that help flesh out the method to load development he proposed. I recently tried it out, and although at first I admit I was a little skeptical … after seeing the real world results and some critical thinking about what we are really trying to uncover when doing load development, his ...
Read More »Lapua 223 Rem Brass Weight Variation
I recently weighed 100 pieces of brand new Lapua 223 Remington “Match” brass, and honestly I’m disappointed. A few people have been telling me how good Lapua brass was, so I was simply expecting more consistency than what I found. It didn’t stack up well compared to some Norma brass I weighed recently … although the overall quality appears to be good. In fact, it wasn’t much different than weight distribution of some super-cheap, once-fired Remington 223 brass I bought for 1/5 of the price (the average deviation of the Lapua brass was actually higher). Here is the resulting data for the Lapua brass, so you can compare for yourself: Average ...
Read More »Most Accurate Rifle Primers for Precision Reloading
What is the best primer? This is a perennial question for handloaders pursuing optimal accuracy, whether that is for a benchrest rifle, F-Class, or long-range tactical setup. The primer is likely the reloading component most shooters know least about, and when that is the case it is sometimes a good idea to just start by looking at what the experts are using. I decided to aggregate the load data listed on 6mmBR.com for various cartridges, to see how many times each type of primer was referenced. I chose 6mmBR.com, for a few reasons: 6mmBR.com is respected in the shooting community and peer-reviewed The majority ...
Read More »Berger 7mm 180gr VLD Bullets Weight Variance
Like most things in handloading … the more uniform one round is to the next, the more uniform ballistics you can expect. That is why I weight sort my bullets, and for my match grade ammo I only load bullets that have exactly the same weight (+/- 1/10 grain). I recently weight sorted a box of Berger 7mm (.284) 180 grain Match Grade VLD Hunting bullets, and here are the results: Average = 179.89 grains Standard Deviation = 0.085 grains Extreme Spread = 0.4 grains Extreme Spread as % of total weight = 0.2% (this is amazing) Bullet: Berger Bullets 180 ...
Read More »Norma 7mm Rem Mag Brass Review
I’ve been using Norma’s brass for the 7mm Remington Magnum lately, and thought I’d write a review over what I’ve found so far. Norma is a high-end, European brass manufacturer similar to Lapua. They use the highest quality raw materials, and have very narrow tolerances and tight quality control. Like Lapua, they drill the flashholes on their brass instead of punching them. Almost all other brass manufacturers punch their flashholes, which can cause inconsistency and require that you debur the flash hole. Also like Lapua, Norma anneals the neck on all of their brass. However, that isn’t as apparent as it is ...
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