Monday Gunday: Phoning it In

I took a mental health day today because the stress levels in my house are getting toxic, so here's a picture from last weekend (I think) where I took my Mosin-in-its-Archangel-stock out to the range and ran about 50 rounds through it... the scope had gotten jostled a bit while I put it into the new stock and I decided to re-zero it. I decided that I wanted it to be 2 inches above center mass at 25 yards because, through some ballistics that I barely understand*, that means I ought to be dead-on at 300 yards.

That's a 21mm grouping, if you don't count the flyer. (Damn gravity fluctuations... grumble.) I believe that's pretty close to 3 MOA, which is a much tighter grouping than previous tries with the rifle. I'm not certian if it's because the Archangel stock delivers better performance, or if I've just become a better shot through practice, or some combination of the two.

Clearly I need to shoot it more so I can give it a better report, but like the title says... I'm phoning it in today. 

* I shall try to explain. 

Because a scope is mounted above a rifle's barrel, the focal point must be adjusted downward so that it intersects the path of the bullet. This means that when you are looking through your scope at a target in front of you, your rifle's barrel is actually pointing slightly upwards, so your bullets will arc upwards for a bit until gravity and air friction slow it enough that it starts to come down.

Interestingly enough, all bullets do this, so the thing about ballistics is finding the points where the rising equals the falling. If you do that, then you can zero your scope at the shorter range where it's easier to see the grouping and know that you're good to a further distance. 

So looking at the Mosin-Nagant round, you see that it intersects at both 25 yards and 200 yards, so if you zero a Mosin at 25 you're good at 200. Based on some vaguely-recalled calculations from other people, 2" high at 200 ought to be dead-on at 300. 

Why 300? I dunno. Maybe I'm just feeling badass. 

http://www.7.62x54r.net/MosinID/20041231001.jpg