Post by Richard on Feb 25, 2021 16:39:47 GMT -5
A group and a little story
Went to the range Tuesday with my partners Bill and Herman. We all started shooting and using our LabRadar’s. Funny, all three of us were having mixed problems with our LR’s …………..kept getting the message “could not track projectile!” Out of my first two shots at 100 yards, I only captured shots #2 and 5 out of six. Tried readjusting the unit.; I have a “sighter” mounted on it and had it set were I normally do but still no luck. I mentioned to my partners that I always capture shot at 300 so I switched to my 300 yard target capturing the next 17 shots in a row?
? Yes, this was early morning but still light? We used to encounter problems early in the morning with our conventional chronographs. But here, normally, I have had no problem in the mornings with the LR???Humph? Oh, and yes, I have that LR trigger installed like Deadeye uses.
Would not think light figures into the equation since Doppler radar pings off the back of the bullet?
Anyway, so here is another story……… This is from my last group at 300 yards. Previous groups at 100 and 300 were not all that great but not horrible either. My load here is 10/68 of N-110 and H-4198 with a 300 grain Fury II. I will list the six velocities:
1-3039, 2-3047, 3-3066, 4-3063, 5-3063, 6-3087 (?)
Shots 1, 2 and 3 formed a nice .747” vertical group. NOTE: a time or two during my prior shooting, I thought I felt something rattle when moving my rifle from the rest to the loading bench but could not say for sure or put my finger on it? So, I load up for shot number 4. When I put the gun back in my sled it normally lines up almost perfectly. But (vertical wise) (my rear leg is used to adjust horizontal and is always slightly off the bull)
Not this time. The crosshairs were either high or low (don’t recall). I tried jostling the rifle to get it to settle in but to no avail? So, I physically had to change the elevation to get back on the bull. My wind flag was looking pretty good so I pulled the trigger and low and behold, the shot left the group about 2+ inches to the right? If you look at the velocity of shots 3 and 4, they are only 3 fps apart? As I was taking the rifle from the rest, I again felt this sort of rattle and when I grabbed the block I have on the toe of the stock………wow! It was practically falling off? The bottom machine screw was almost all the way out and the rear screw was missing? Bill saw it on the floor behind me. So this is what was causing the vertical I was experiencing and had to adjust for. (I had, had the rifle completely apart a month ago to color sand and re-compound the lacquer finish. Apparently, when I assembled it, I failed to fully tighten those screws )
So, loaded up shot #5 at the same velocity as #4 and it pretty much went into my nice group, only opening it up 2 tenths. So, in trying for a five shot group, (I eliminated shot #4) #6 went almost an inch high but the velocity also went some 32 fps higher than the average of the first five. The high velocity explains the high impact. So why did the velocity go up? Beats the you know what out of me? The main charges are all measured. The booster are metered but are rarely off my more than a tenth or two.
So, the fact that the butt of the stock was sitting in a wobbly condition, even though I was able to adjust my sight, upon firing, it caused what you see on the target. This is why rifle and rest set ups must be repeatable for precision shooting. Yes, it would have killed a deer at 3 or 4 hundred yards, but would not win any trophies at the Challenge! In the Benchrest game, it’s all about how well your rifle “rides the bags!” This was a prime example only on my much customized led sled and base.
Went to the range Tuesday with my partners Bill and Herman. We all started shooting and using our LabRadar’s. Funny, all three of us were having mixed problems with our LR’s …………..kept getting the message “could not track projectile!” Out of my first two shots at 100 yards, I only captured shots #2 and 5 out of six. Tried readjusting the unit.; I have a “sighter” mounted on it and had it set were I normally do but still no luck. I mentioned to my partners that I always capture shot at 300 so I switched to my 300 yard target capturing the next 17 shots in a row?
? Yes, this was early morning but still light? We used to encounter problems early in the morning with our conventional chronographs. But here, normally, I have had no problem in the mornings with the LR???Humph? Oh, and yes, I have that LR trigger installed like Deadeye uses.Would not think light figures into the equation since Doppler radar pings off the back of the bullet?
Anyway, so here is another story……… This is from my last group at 300 yards. Previous groups at 100 and 300 were not all that great but not horrible either. My load here is 10/68 of N-110 and H-4198 with a 300 grain Fury II. I will list the six velocities:
1-3039, 2-3047, 3-3066, 4-3063, 5-3063, 6-3087 (?)
Shots 1, 2 and 3 formed a nice .747” vertical group. NOTE: a time or two during my prior shooting, I thought I felt something rattle when moving my rifle from the rest to the loading bench but could not say for sure or put my finger on it? So, I load up for shot number 4. When I put the gun back in my sled it normally lines up almost perfectly. But (vertical wise) (my rear leg is used to adjust horizontal and is always slightly off the bull)
Not this time. The crosshairs were either high or low (don’t recall). I tried jostling the rifle to get it to settle in but to no avail? So, I physically had to change the elevation to get back on the bull. My wind flag was looking pretty good so I pulled the trigger and low and behold, the shot left the group about 2+ inches to the right? If you look at the velocity of shots 3 and 4, they are only 3 fps apart? As I was taking the rifle from the rest, I again felt this sort of rattle and when I grabbed the block I have on the toe of the stock………wow! It was practically falling off? The bottom machine screw was almost all the way out and the rear screw was missing? Bill saw it on the floor behind me. So this is what was causing the vertical I was experiencing and had to adjust for. (I had, had the rifle completely apart a month ago to color sand and re-compound the lacquer finish. Apparently, when I assembled it, I failed to fully tighten those screws )
So, loaded up shot #5 at the same velocity as #4 and it pretty much went into my nice group, only opening it up 2 tenths. So, in trying for a five shot group, (I eliminated shot #4) #6 went almost an inch high but the velocity also went some 32 fps higher than the average of the first five. The high velocity explains the high impact. So why did the velocity go up? Beats the you know what out of me? The main charges are all measured. The booster are metered but are rarely off my more than a tenth or two.
So, the fact that the butt of the stock was sitting in a wobbly condition, even though I was able to adjust my sight, upon firing, it caused what you see on the target. This is why rifle and rest set ups must be repeatable for precision shooting. Yes, it would have killed a deer at 3 or 4 hundred yards, but would not win any trophies at the Challenge! In the Benchrest game, it’s all about how well your rifle “rides the bags!” This was a prime example only on my much customized led sled and base.
