My standard load for my AR-10 in 260 Rem has been using Lapua cases and Lapua 139-gr Scenars. Note that I automatically used Lapua cases because I use them in my bolt guns.
But I was becoming tired of losing expensive brass at PRS matches and began thinking about the necessity of premium brass. I didn't have any other 260 Rem brass, but I had large amounts of 7.62X51 brass from when I still was physically able to compete in NRA High Power matches.
I dug around and found a box of unused RA 64 cases and ran a test batch through my .260 Rem dies. That went well, so I got out my neck-turning equipment that happened to still be set to the correct cutting depth for my AR.
Because I didn't do all my homework when I had the rifle made, I had my 'smith (against his recommendation) chamber the Krieger barrel with a fairly tight neck, like I do with my bolt rifles. I quickly discovered the error of my ways because it meant I had to neck turn even my Lapua brass, and play with the recoil system.
I loaded just 10 cases for the first test, which showed that the brass played nicely with my AR. So I made a set of 5-shot test loads because I knew (after weighing cases) that the RA 64 was heavier than the Lapua, indicating a slightly smaller interior volume with a corresponding pressure increase. In addition to my normal Lapua Scenars, I also used Berger 140-gr VLD and Hornady 140-gr ELD-M bullets that had not performed well in previous tests.
To get to the punch line, I tested loads at 200 yards and found four that grouped into .5 MOA and one that went .75 MOA. The Lapua Scenar still edged out the Berger and the Hornady, but not by enough to make a difference with me behind the trigger. I also think the Berger performs better past the 200-yard test range. I'm consistently hitting the steel at 800 yards and now need to back off to the 1200-yard line.
All loads were tested with my Thunderbeast suppressor mounted. All successful loads chronographed within 15 fps of my original Lapua case-and-bullet load. All loads used H4350 powder and Federal Match primers.
So, my limited test indicates that bullets and properly prepared brass seem to play a more important role than whether or not the brass is premium. And I'm happier losing inexpensive cases.
Cheers,
Richard
But I was becoming tired of losing expensive brass at PRS matches and began thinking about the necessity of premium brass. I didn't have any other 260 Rem brass, but I had large amounts of 7.62X51 brass from when I still was physically able to compete in NRA High Power matches.
I dug around and found a box of unused RA 64 cases and ran a test batch through my .260 Rem dies. That went well, so I got out my neck-turning equipment that happened to still be set to the correct cutting depth for my AR.
Because I didn't do all my homework when I had the rifle made, I had my 'smith (against his recommendation) chamber the Krieger barrel with a fairly tight neck, like I do with my bolt rifles. I quickly discovered the error of my ways because it meant I had to neck turn even my Lapua brass, and play with the recoil system.
I loaded just 10 cases for the first test, which showed that the brass played nicely with my AR. So I made a set of 5-shot test loads because I knew (after weighing cases) that the RA 64 was heavier than the Lapua, indicating a slightly smaller interior volume with a corresponding pressure increase. In addition to my normal Lapua Scenars, I also used Berger 140-gr VLD and Hornady 140-gr ELD-M bullets that had not performed well in previous tests.
To get to the punch line, I tested loads at 200 yards and found four that grouped into .5 MOA and one that went .75 MOA. The Lapua Scenar still edged out the Berger and the Hornady, but not by enough to make a difference with me behind the trigger. I also think the Berger performs better past the 200-yard test range. I'm consistently hitting the steel at 800 yards and now need to back off to the 1200-yard line.
All loads were tested with my Thunderbeast suppressor mounted. All successful loads chronographed within 15 fps of my original Lapua case-and-bullet load. All loads used H4350 powder and Federal Match primers.
So, my limited test indicates that bullets and properly prepared brass seem to play a more important role than whether or not the brass is premium. And I'm happier losing inexpensive cases.
Cheers,
Richard
