Riddle me this Riddle me That

[BigBlack]

Okay new reloader still learning as much as possible. I have been working on my 243 loads and am getting MOA groups at 100 yards pretty consistently now. Preparing it for hunting I fine tuned the scope adjustments and then popped off a few groups at 200 yards. Surprisingly my groups were only about 1.25" to 1.5" consistently. So at 100 yards I am about 1 MOA consistently then at 200 yards .6 to .7 MOA, why not closer to 2 MOA. I was under the impression (remember new reloader here) that if my group size was 1" at 100 yards I could expect 2" at 200 yards and 3" at 300 yards and so on.

Wind was relatively nonexistent this trip.

Not looking for flames only instruction or enlightenment.

Thanks
BB

 

[Dick]

I think my first question would be "how many groups?" You could be seeing those results simply by chance. If you post the actual individual group sizes at each distance I could test them statistically for you and see what the probability is that you got those results simply by chance.

That aside, I have read articles by those who note that bullets "precess" as they leave the barrel. Precession refers to a circular change in the axis of rotation - think of a spinning top, which is much like a bullet. The top is stabilized by spinning very fast, but the axis of rotation of the top (i.e., the tip of the top, so to speak), describes its own, circle of slower rotation, which will sometimes get smaller and diminish to near zero as the top continues spinning.

The precession theory of decreasing MOA at longer ranges says that the bullet is still precessing at 100 yards, but settles down between 100 and 200 (or whatever), thereby resulting in smaller MOA. I'm not sure I buy it, frankly. To be correct, the decrease in precession has to result in the bullet returning to the line of sight each time, i.e., a bullet diverging to the right of the LOS has to curve left as precession decreases, while one diverging to the left has to curve right, and up/down, etc. I don't see how the precession argument can explain that.

 

[BIG GUN]

I have a number of firearms that shoot tighter groups at 2-300yds. I just write it off to bullet stablization.

 

[jkelly]

If indeed you are capable of repeatedly grouping better at 200 yards then at 100 yards, I'd guess your scope/sight to target size is better for you at two hundred yards. You could try a smaller target at 100 yards and see if your accuracy improves.

Respectfully,

jkelly