Re: Actual speed of Eley ammo?
Posted: Wed Dec 23, 2009 11:57 pm
More testing today. Across 16 shots of the Eley Club Extra (EPS) out of the Marlin 57, I got a high velocity of 986.3fps (not counting the 1001fps on the first shot from a clean barrel) and a low velocity of 914.8fps. Here are the actual values so you can see the distribution:
1001, 984.2, 955.9, 972.9, 956.0, 968.3, 986.3, 954.8, 963.2, 947.2, 936.8, 914.8, 945.7, 981.9, 947.1, 944.3, 961.2
Temperature was 40 degrees (f), humidity was 80%, and elevation was the same ~400ft as before. Accuracy wasn't as good as the two groups that I shot previously. It was on par with the low-price ammo, actually, hovering around 4" for 5 shots at 100m. By contrast, the same ammo shot from my 1712 with the 25" Lilja tightbore barrel had these velocities:
1084 (clean barrel), 1037, 1025, 1041, 1056, 1030, 1065, 1049, 1041, 1028
The group from the 1712 (not counting the first shot, clean barrel flyer that was 1/2" outside the group) was just barely under an inch. That led me to believe that it was a problem with the Marlin 57 rifle, as it wasn't nearly as accurate (expected) and lost a lot of velocity compared to the 1712. When trying other ammo, the Eley Standard and Silhouex grouped about as poorly as the Club Extra EPS and had the same average velocity and fairly wide spread. The Golden Eagle Target did better, with both 5-shot groups below 2.5" and velocities fairly evenly distributed from 987.5 to 1028fps, with a flyer of 1052fps in the middle of one string. As a note, I won't shoot this lot of Golden Eagle Target in the 1712 even though I have several bricks of it left because it's a bit oversize and quickly gets hard to load in the tight match chamber. As a last effort, I tried some Federal 711b that I have from a brick that I bought a couple years ago that I haven't had shoot well in any of the several guns that I've tried it in. Surprisingly, this ammo shot two 5-shot groups (all I had time for) less than 2" center-to-center and had velocities from 1038 to 1060fps. I don't really have an explanation for that, as I don't remember that ammo shooting that well even in the 1712.
I'm hopeful that I might actually be able to use the Federal 711b, as the velocities were up there where I want and the accuracy was decent, too. It's way too soon to tell, though, as I ran out of time after only firing 10 shots of the 711b. About the only thing I'm sure of so far is that there is a lot about rimfire ballistics that I don't understand. I do trust the velocity readings of the chronograph a bit more now. Will keep testing and report back. Keep the feedback coming.
1001, 984.2, 955.9, 972.9, 956.0, 968.3, 986.3, 954.8, 963.2, 947.2, 936.8, 914.8, 945.7, 981.9, 947.1, 944.3, 961.2
Temperature was 40 degrees (f), humidity was 80%, and elevation was the same ~400ft as before. Accuracy wasn't as good as the two groups that I shot previously. It was on par with the low-price ammo, actually, hovering around 4" for 5 shots at 100m. By contrast, the same ammo shot from my 1712 with the 25" Lilja tightbore barrel had these velocities:
1084 (clean barrel), 1037, 1025, 1041, 1056, 1030, 1065, 1049, 1041, 1028
The group from the 1712 (not counting the first shot, clean barrel flyer that was 1/2" outside the group) was just barely under an inch. That led me to believe that it was a problem with the Marlin 57 rifle, as it wasn't nearly as accurate (expected) and lost a lot of velocity compared to the 1712. When trying other ammo, the Eley Standard and Silhouex grouped about as poorly as the Club Extra EPS and had the same average velocity and fairly wide spread. The Golden Eagle Target did better, with both 5-shot groups below 2.5" and velocities fairly evenly distributed from 987.5 to 1028fps, with a flyer of 1052fps in the middle of one string. As a note, I won't shoot this lot of Golden Eagle Target in the 1712 even though I have several bricks of it left because it's a bit oversize and quickly gets hard to load in the tight match chamber. As a last effort, I tried some Federal 711b that I have from a brick that I bought a couple years ago that I haven't had shoot well in any of the several guns that I've tried it in. Surprisingly, this ammo shot two 5-shot groups (all I had time for) less than 2" center-to-center and had velocities from 1038 to 1060fps. I don't really have an explanation for that, as I don't remember that ammo shooting that well even in the 1712.
I'm hopeful that I might actually be able to use the Federal 711b, as the velocities were up there where I want and the accuracy was decent, too. It's way too soon to tell, though, as I ran out of time after only firing 10 shots of the 711b. About the only thing I'm sure of so far is that there is a lot about rimfire ballistics that I don't understand. I do trust the velocity readings of the chronograph a bit more now. Will keep testing and report back. Keep the feedback coming.