Part 4 of my Precision Experimentation
For those of you who are puzzled about the titles this month I recently listened to a free audio recording of Moby Dick. It’s very slow by modern standards, but by about half way in it becomes very compelling. At this point in my story, I haven’t battled the whale, but a far off spout in the distance makes me think I have seen it.
I continued with my precision experiments today. After my experiment with left handed shooting I started processing what I had seen, and what the results on paper were. To refresh your memory, I had seen a blurry reticle with my left eye that sometimes looked like 2 vertical stadia right next to each other. The group I shot was this:
It got me thinking about reticle focus, mostly during my thinking time in the bathroom. Then I asked Ilya a question about parallax (via email, not in the bathroom), and he also happened to mention reticle focus. So I refocused my ocular, which was probably a good idea. All this sewing and typing is not great for the eyes.
One thing that was apparent to me is that I really have a difficult time focusing the reticle. It’s hard to make it blurry. My eyes focus on it too quickly. I did like I was supposed to, and put it in the blank, overcast sky, but really had a hard time getting it to look out of focus at all through its entire range. There were a couple of bad spots, but it was really not easily apparent. I was still not satisfied it was “on” after setting it and looking at some distant stuff, so I loosened the retaining nut and did it again.
Another thing I noticed was that when the retaining nut is loose, the reticle and scope image move a great deal with any small movement of the ocular. This got me wondering, “How firmly had the nut been fastened before?” I know that I did not make a point of getting it as tight as possible.
I ended up looking at a yield sign approximately 900 yards away through the scope at 9x. I got the adjustment to where both the sign and the reticle were focused at the same time. It is probably not the right way, but it was the only way I could tell a difference that seemed more than fleeting.
On to the range. I always look for cars as I approach, because being precociously crotchety I tend to avoid human contact if at all possible. If it is inevitable, then I have to steel myself for some small talk. My scan for cars was disrupted by two smouldering piles near the target area. Then I confirmed no cars. Good!
The piles of garbage that Mark suggested I truck out to get in good with the range brass were mostly gone, being burnt up. Getting out of my car to unlock the gate, I took in the smell of the burning piles, which smelled exactly like safe and sane Chinese fireworks. Nice, it reminded me of nearly blown off fingers and bottle rocket wars. Luckily the wind was blowing the smoke away from causing any obstruction to my target pallet. This target pallet was not as sturdily braced as the previous one, and my 15 round aggregate group had been removed. Oh well.
First comes the 3 round cold bore. I was not especially comforted:
Next I shot the 5 round group using the same methodology that I used for the control group, because changing the ocular focus means that I have changed something worth isolating:
That was not impressive either. Sometimes I think that after a loose nut is tightened, there has to be some “seating in” shots to get everything where it wants to end up.
The next thing I tested came at the recommendation of a friend who goes by AKJaeger as a commenter here. Let’s just say that he knows his stuff. It was his experience with a Model 70 that the bolt knob popping up slightly had a deleterious effect on his precision. This popping up is evident on my rifle during dry fire. He said that he had this fixed by Shawn Carlock and the rifle shot very well after that. He showed me that lifting the bolt handle almost imperceptibly after closing it would greatly lessen the its movement during dry fire. It really didn’t pop up, it just moved a bit.
For the next five rounds I gently moved my bolt knob up after closing it the smallest amount I could move it:
1.03” < 1.047”, hence 1.03” = sub MOA. A welcome development.
This was the first time that the second experimental group of the day was better than the first. This is comforting from the perspective that my rifle is perhaps not affected too much by getting warm. I’m wondering how much of this was the refocused ocular.
I could tell after firing that group that the bolt movement had not been isolated as an experimental variable very well. I could feel that my entire shooting process was running more smoothly. Why? I don’t know, but I felt more there.
I know that one of the ways to reinforce a good performance is to do more of it. I did not have a fresh target up, and there was not really anything that stood out on the target that would give me a pinpoint indicator to shoot at. I did not want to get up and go downrange, because I was in the magic moment. I aimed at the “re-control” target in a spot where the printed words below the target seemed somewhat dense. Here’s the entire target:
Once I had a bullet hole to aim at, the next three rounds seemed to follow right into it. That’s the 4 rounds on the lower left, group size 0.47”.
I did not wait the 30 seconds in between shots, but I did not rush. The average time interval was probably about 10 seconds. I did not raise the bolt knob at all- just worked it briskly. I had five rounds loaded. The 5th went hard right, which opened up the 5 round group to 2.08”. That’s called keeping me humble. To prove that I still had my mojo working, I used that bullet hole as the point of aim for round six, which landed right on top of it, making a new 2 round group of 0.24”, which turned a slight defeat into a fabulous victory. The human mind is a mysterious thing. I have more complexity than a 50 year-old Cuban cigar.