Upper - BCM BFH ELW 16-inch mid-length
Ammo - Speer LE .223 75 Gold Dot
I've had this upper for years and have been very happy with it (still am). I usually shoot this rifle at 100 yards or less, but today I tweaked my zero at 200 yards to achieve my desired MPBR of about 230 yards.
First 3-shot group at 200 yards measured 1-1/2 inches, the second 3-shot group at 200 measured 1-3/4 inches. With the zero confirmed, I settled down for some 5-shot groups.
What I was finding in 5-shot groups is that the rifle would cluster four in a MOA group or better (like the first two groups), then the fifth shot was WAY out of the group, opening it up to around 3 MOA. It did this pretty consistently, able to get most of the shots in a tight cluster then sending one in five out into left field somewhere. One group at 300 yards clustered four of the shots within 4 inches, then sent the fifth to open the group to 10 inches (about 3 MOA)
I was shooting prone with bags front and rear, squeezing the shots off carefully, so I don't think there was anything I was doing to force the flyers. Other ammo is usually in the 2 - 3 MOA range but doesn't consistently cluster tight groups like the GD ammo.
Question - is there something I should be looking for mechanically that might account for this behavior? Or is this typical of lightweight barrels?
TIA for your insight.
Bookmarks