Gents:
I have recently started a couple of threads looking for help on my reloading technique. I have been pretty careful and consistent with my reloading, but usually end up with large SD and ES. This past weekend I did something a little different that seems to suggest that it is not the reloads, but rather the shooter or the gun.
I should say that I posted this on Benchrest Central, but I am hoping to get a broader response.
The day was overcast, calm and 47-51 deg. I shoot a Savage F/TR 308, but I was shooting off a bench with a Hart rest. I warmed the barrel up with 5 rounds running about 2,720 fps. I then went and set up my CED chronograph.
I then shot 20 more rounds at 4 different powder charges as shown below. Note however, the sequence that I shot these in.
43.2 43.4 43.6 43.8 (VARGET, 175 GN SIE MK)
2,723 2,716 2,735 2,738
2,734 2,730 2,744 2,749
- - - -
2,740 2,737 2,757 2,751
2,748 2,744 2,756 2,762
I shot the first flight [43.2 - 43.8]. I took my time shooting, but didn't specifically wait a long time between shots. I then shot the second flight. Two patterns are clearly developing (described below). Then the clouds came in and the chron wouldn't register, so I took a break until a cease fire was called (~15 min) and then went out and took the screens off the CED. I then fired the 4th and 5th flights.
Two things are evident from the data: first, 43.4 is consistently the lowest of the four powder charges, but second and MORE IMPORTANTLY from an ES/SD perspective, the speeds increase over time at each load!
I should say that the barrel was warm to the touch, but not hot like you would get when you put 20 rounds down range in an F-Class shoot on a hot day.
Does this make sense to anyone?
Thanks, Mike
I have recently started a couple of threads looking for help on my reloading technique. I have been pretty careful and consistent with my reloading, but usually end up with large SD and ES. This past weekend I did something a little different that seems to suggest that it is not the reloads, but rather the shooter or the gun.
I should say that I posted this on Benchrest Central, but I am hoping to get a broader response.
The day was overcast, calm and 47-51 deg. I shoot a Savage F/TR 308, but I was shooting off a bench with a Hart rest. I warmed the barrel up with 5 rounds running about 2,720 fps. I then went and set up my CED chronograph.
I then shot 20 more rounds at 4 different powder charges as shown below. Note however, the sequence that I shot these in.
43.2 43.4 43.6 43.8 (VARGET, 175 GN SIE MK)
2,723 2,716 2,735 2,738
2,734 2,730 2,744 2,749
- - - -
2,740 2,737 2,757 2,751
2,748 2,744 2,756 2,762
I shot the first flight [43.2 - 43.8]. I took my time shooting, but didn't specifically wait a long time between shots. I then shot the second flight. Two patterns are clearly developing (described below). Then the clouds came in and the chron wouldn't register, so I took a break until a cease fire was called (~15 min) and then went out and took the screens off the CED. I then fired the 4th and 5th flights.
Two things are evident from the data: first, 43.4 is consistently the lowest of the four powder charges, but second and MORE IMPORTANTLY from an ES/SD perspective, the speeds increase over time at each load!
I should say that the barrel was warm to the touch, but not hot like you would get when you put 20 rounds down range in an F-Class shoot on a hot day.
Does this make sense to anyone?
Thanks, Mike