Tag Archives: Bullet Seating Depth

This is the last post in a series of articles focused on bullet jump research that has been conducted more than two years by Mark Gordon of Short Action Customs (Who is Mark Gordon?). In this post, I’ll provide an executive summary of what we covered and provide a few tips for how to apply this new knowledge in our load development. The first article provided a comprehensive overview of what 10+ of the most respected books and reloading manuals had to see about bullet jump and laid the foundation of what bullet jump is, along with other concepts like ...

Are you one of those guys who has been reading this series of posts on bullet jump, and thinking to yourself, “Well, my 0.020” bullet jump sure seems to be working fine. Doubt this would be any improvement over what I’ve already got!” This is the post for you! As Mark started sharing some of his bullet jump findings with a few shooters, he met some skepticism – even from sponsored shooters on his Short Action Customs team. Here is how Mark tells one of those stories:  “After we’d already done most of this bullet research, we had Solomon from ...

This post shares more of Mark Gordon’s research on bullet jump, which is very interesting, original research – and has everyone talking! This post looks at research data on the Hornady’s 6.5mm 147 gr. ELD-M and Tubb’s 6mm 115 gr. DTAC RBT bullets. Check it out!

This landmark article shares new, primary research that Mark Gordon from Short Action Customs has compiled over the past 2 years. He tested a wide range of bullet jumps in several rifle/load configurations, and this post shares the analysis of that data. Mark used a similar approach to the Audette Ladder Test and OCW method, but the goal was to not find the most forgiving powder charge weight, but the most forgiving bullet jump. He wasn’t looking for the specific bullet jump that grouped the best, but the largest window of bullet jumps that provided a similar point of impact. That means the rifle would be more consistent from the start of the match to the end of it or could shoot a particular kind of match-grade factory ammo really well for a longer period of time. Mark’s findings may seem counter to conventional wisdom when it comes to bullet jump, but a few national-level precision rifle competitors also support the idea, which I highlight in this post as well.

This article focuses on how quickly the lands of a rifle barrel usually erode, especially for mid-sized cartridges that are popular in precision rifle matches. It also explains how many shooters try to manage their seating depth and bullet jump over the life of the barrel. These are topics don't seem to get much attention and are rarely discussed in any comprehensive format, so hopefully it provides some useful information and tips. The article also poses some questions that might make us rethink priorities when it comes to managing bullet jump, at least when applying the concepts to some specific shooting disciplines where you might fire 100-200 rounds over the course of a weekend.

With so many events canceled and stores closed, what a great time to do some reloading! Over the past several weeks, I have been working on a series of posts that I'm very excited to finally share with you guys! This article provides a comprehensive overview of what most professionally published books and reloading manuals suggest about bullet jump and seating depth when it comes to precision rifles. I have a big stack of books on the subject, and I tried to combine the most relevant info from each of them when it comes to fine-tuning the seating depth of your ammo.