Post by Richard on Jun 9, 2020 18:53:43 GMT -5
Just some shooting results…
As I had mentioned a couple of weeks ago, I had a problem with scope mount loosening. Last week I only shot it a few times to get it zeroed back to where it should be. Had other guns to play with and hence, did not do my usual write up.
Again, this week, I had another rifle I was switching scopes on for a special shoot the club is having so I did not too my usual amount of SML shooting. I did however fire two groups at 300 yards with a load of 8208 that looked promising in my earlier Satterlee testing………that being 90.5 gr.with a 350 gr. AeroMax.
The first group was not all that good. I did notice that the velocity was up around 25 fps faster than when I did the previous testing. Today was around 89* and the tests were done at 50*. I had gotten three fps ES from two shots back then and 26 fps today. Maybe the temperature attributed to the higher ES? Maybe I need to drop back a grain to lower the velocity? These are things you don’t know until you test. If you don’t shoot a lot, you don’t find these things out? This is why I keep accurate notes and refer back to them when I see changes. So this first group had three shots in 1.7”, the best four in 1.7” and all five in 2.3”. At the Kentucky Challenge, you had better be in and around ¾” for first place at 300 yards.
So then I let the rifle sit for around an hour while I shot my .22 and the BS with another member before shooting the second group. Note here: These bullets had just been resized the the night before and were going down the barrel with a one handed seating. Every bullet seated identical. Also Note: after the last group, I made a one click up and one click right change to the NF 12x42 BR scope. I physically watched the crosshairs move as I clicked (1/8”). Therefore, I was expecting the group to generally move up and to the right some……right? Well, the first shot was 2 ½” low of the subsequent group?? The velocity was well within the parameters of this load? As can be seen in the subsequent shots, this velocity fit right in? As a matter of fact, lower and higher velocity shots hit inside the group. So, not panicking and making an immediate adjustment, I fired the second shot which hit about where I expected it, followed by four more shots (a total of 6 shots). Shots 4,5 and 6 (three shot group) came in at .791” with all five 1.458” The ES was larger than I prefer at 37, but those shots hit within 1 ½”. When you look at the ballistic tables and vary the velocity by 37 fps, …….at 300 yards, you are only talking “tents” of an inch difference. Probably at 600, the difference would be more sizable and so on out to 1,000 and beyond. Unless 37 fps makes a big change in the vibration pattern------concerning at what point the bullet leaves the muzzle, the vertical aspect is not a major concern at these closer distances.
So my question is, why did that first shot hit low? The wind was a non-issue as I could see my daisy wheel wind flag in my scope and it was doing NOTH-ING! How about the trigger puller? Well, I was confident that it as undisturbed in breaking as the following five shots. I know we have seen that when a barrel cools for period that some “crust” seems to form and causes the next bullet to go down a little rougher? I did not seem to notice this as the bullets are sized relatively loose? Or maybe it was just the SML Gods?
As I had mentioned a couple of weeks ago, I had a problem with scope mount loosening. Last week I only shot it a few times to get it zeroed back to where it should be. Had other guns to play with and hence, did not do my usual write up.
Again, this week, I had another rifle I was switching scopes on for a special shoot the club is having so I did not too my usual amount of SML shooting. I did however fire two groups at 300 yards with a load of 8208 that looked promising in my earlier Satterlee testing………that being 90.5 gr.with a 350 gr. AeroMax.
The first group was not all that good. I did notice that the velocity was up around 25 fps faster than when I did the previous testing. Today was around 89* and the tests were done at 50*. I had gotten three fps ES from two shots back then and 26 fps today. Maybe the temperature attributed to the higher ES? Maybe I need to drop back a grain to lower the velocity? These are things you don’t know until you test. If you don’t shoot a lot, you don’t find these things out? This is why I keep accurate notes and refer back to them when I see changes. So this first group had three shots in 1.7”, the best four in 1.7” and all five in 2.3”. At the Kentucky Challenge, you had better be in and around ¾” for first place at 300 yards.
So then I let the rifle sit for around an hour while I shot my .22 and the BS with another member before shooting the second group. Note here: These bullets had just been resized the the night before and were going down the barrel with a one handed seating. Every bullet seated identical. Also Note: after the last group, I made a one click up and one click right change to the NF 12x42 BR scope. I physically watched the crosshairs move as I clicked (1/8”). Therefore, I was expecting the group to generally move up and to the right some……right? Well, the first shot was 2 ½” low of the subsequent group?? The velocity was well within the parameters of this load? As can be seen in the subsequent shots, this velocity fit right in? As a matter of fact, lower and higher velocity shots hit inside the group. So, not panicking and making an immediate adjustment, I fired the second shot which hit about where I expected it, followed by four more shots (a total of 6 shots). Shots 4,5 and 6 (three shot group) came in at .791” with all five 1.458” The ES was larger than I prefer at 37, but those shots hit within 1 ½”. When you look at the ballistic tables and vary the velocity by 37 fps, …….at 300 yards, you are only talking “tents” of an inch difference. Probably at 600, the difference would be more sizable and so on out to 1,000 and beyond. Unless 37 fps makes a big change in the vibration pattern------concerning at what point the bullet leaves the muzzle, the vertical aspect is not a major concern at these closer distances.
So my question is, why did that first shot hit low? The wind was a non-issue as I could see my daisy wheel wind flag in my scope and it was doing NOTH-ING! How about the trigger puller? Well, I was confident that it as undisturbed in breaking as the following five shots. I know we have seen that when a barrel cools for period that some “crust” seems to form and causes the next bullet to go down a little rougher? I did not seem to notice this as the bullets are sized relatively loose? Or maybe it was just the SML Gods?
