10-03-2011, 06:16 PM
I appreciate all the replies, gentlemen (I assume everyone in this thread is male).
It took a long time, a lot of factory ammo, and sheer luck in reloading, but I finally discovered that the issue wasn’t me so much as it was the gun/ammo combination. Until a couple weeks ago, all my “precision” shooting was with factory ammo. I spent a fair amount of coin on what most would consider good ammo for the 308, 223, and the Grendel. I bought and shot Fed GMM, Hornady Amax Match, AA Lapua 123, and other quality loads for those three calibers. On occasion I’d manage a ¾ MOA five-round group, but most five-round groups hovered in the 1 to 1.5 MOA range when I felt confident that I had done a good job behind the trigger. I just assumed that some of these factory loads were capable of much smaller groups, hence I was the weak link in the system. I attributed my inaccuracy to heartbeat artifact, because although I could minimize it quite a bit, I could never completely stop it. I thought I couldn’t time my shots well enough between heartbeats to shoot groups smaller than 1 MOA, so that’s why I started this thread.
In February of this year I purchased a 24” heavy barrel in .264 LBC from Les Baer and planned to use that as my target gun for punching paper, steel, and a container or two of Tannerite at the machine gun shoot. The LBC tube had a glowing reputation and an accuracy guarantee with their target ammo. I read good things about Satern tubes, but for reasons I can’t recall, I decided on the LBC. I took great care in assembling the upper. Got the gun to the range with a couple different LBC loads and one AA load. Perplexingly, the best I managed was a 1.1 inch group at 100. Successive trips to the range with a couple other different loads, Hornday and AA, never consistently bettered that first group size. How could none of five different factory loads, known for spectacular accuracy in other folks’ Grendels, shoot well for me? Had to be the driver that was the problem, or so I assumed.
A few weeks ago I finally picked up a set of Hornady dies in Grendel and put together loads with five different charge weights. I ran 107 grn Sierras over different charges of BL-C(2) and CCI 450s. The first two loads I tried shot about the same as factory loads—one printed about 1 MOA and the other about 1.5 MOA. The third group went into a single, ragged hole, and I was convinced it wasn’t just luck. I got back out to the range today with a few dozen rounds of the same load I used for that tight third group, and while I didn’t print any 1-hole groups, shooting sub-MOA wasn’t difficult. I’ll try tweaking that load to see if I can shrink group sizes a tad, but it’s a relief to know that while I do still have to contend with an amount of heartbeat artifact, I believe my aiming error due to heartbeat artifact is closer to ¼ MOA instead of the 1 or more MOA I thought it was.
It took a long time, a lot of factory ammo, and sheer luck in reloading, but I finally discovered that the issue wasn’t me so much as it was the gun/ammo combination. Until a couple weeks ago, all my “precision” shooting was with factory ammo. I spent a fair amount of coin on what most would consider good ammo for the 308, 223, and the Grendel. I bought and shot Fed GMM, Hornady Amax Match, AA Lapua 123, and other quality loads for those three calibers. On occasion I’d manage a ¾ MOA five-round group, but most five-round groups hovered in the 1 to 1.5 MOA range when I felt confident that I had done a good job behind the trigger. I just assumed that some of these factory loads were capable of much smaller groups, hence I was the weak link in the system. I attributed my inaccuracy to heartbeat artifact, because although I could minimize it quite a bit, I could never completely stop it. I thought I couldn’t time my shots well enough between heartbeats to shoot groups smaller than 1 MOA, so that’s why I started this thread.
In February of this year I purchased a 24” heavy barrel in .264 LBC from Les Baer and planned to use that as my target gun for punching paper, steel, and a container or two of Tannerite at the machine gun shoot. The LBC tube had a glowing reputation and an accuracy guarantee with their target ammo. I read good things about Satern tubes, but for reasons I can’t recall, I decided on the LBC. I took great care in assembling the upper. Got the gun to the range with a couple different LBC loads and one AA load. Perplexingly, the best I managed was a 1.1 inch group at 100. Successive trips to the range with a couple other different loads, Hornday and AA, never consistently bettered that first group size. How could none of five different factory loads, known for spectacular accuracy in other folks’ Grendels, shoot well for me? Had to be the driver that was the problem, or so I assumed.
A few weeks ago I finally picked up a set of Hornady dies in Grendel and put together loads with five different charge weights. I ran 107 grn Sierras over different charges of BL-C(2) and CCI 450s. The first two loads I tried shot about the same as factory loads—one printed about 1 MOA and the other about 1.5 MOA. The third group went into a single, ragged hole, and I was convinced it wasn’t just luck. I got back out to the range today with a few dozen rounds of the same load I used for that tight third group, and while I didn’t print any 1-hole groups, shooting sub-MOA wasn’t difficult. I’ll try tweaking that load to see if I can shrink group sizes a tad, but it’s a relief to know that while I do still have to contend with an amount of heartbeat artifact, I believe my aiming error due to heartbeat artifact is closer to ¼ MOA instead of the 1 or more MOA I thought it was.