Had some fun today.

[Luckus]

I have been waiting for good weather conditions for a few days to do some 600 yard testing. 65 degrees, solid overcast, no wind and very light occassional rain. First five shot group, 5 ". Second round, 3.375, 4 in 2" and 3 in .875. Last group, 5 in 2.292". I know it can be better, but it was my personal best, and it was a hoot. Savage 12 FTR, Rock Creek barrel, 6 Dasher, 33 grs RL15, 450, 105 Amax, 2.815 with a nut, and Weaver T36. Thanks, Luckus

[M.O.A.]

not bad at all

[BobT]

Good shooting Luckus! 2 years ago I thought 300 yards was a long shot, now I'm quickly getting bored with the 500 meter max range at my gun club.
Bob

[Luckus]

It's just fun when it comes together. Makes up for the frustration you go through with the learning curve. Our last match is on Sunday and I hope things keep working as they have, but some days things fall apart no matter how you plan. I know one thing, 6 Dasher is a great cartridge, easy to load for and shoot.

[skypilot]

Congrats on a great shooting day. I enjoy hearing folk's successes with the knowledge and skill set needed to shoot distance. Just curious, any idea on the Density Altitude and your range's elevation?

[mbkmkk]

2.815 with a nut

Sounds very cool. I hope to get a Dasher set up soon.

Not sure what the 2.815 means? What is your Barrel length and FPS on that load?

[Luckus]

The altitude here is (guessing) around 1500 feet. SugarBush hill is 1960 feet and I live at the bottom of it. Density altitude is a term I am not familar with. 2.815 is the overall length of the loaded round with a Sinclair nut included in the measurement. Barrel length 31", last time I chronoed 3030 mv.

[243LPR]

The problem with shooting that far is you need to bring a kid with you to put up targets so you don't have to wait 15 minutes to shoot.Unless your on a range that allows driving.

[skypilot]

Thanks Luckus, that is about the same as my altitude.

[thomae]

Density altitude is a term I am not familar with.

Density altitude is a way of measuring air pressure (density) against a set standard. (Air pressure and density are simply just a way of measuring how many molecules something moving through the air will bump into.)

A "standard day (http://www.faa.gov/library/manuals/aviation/pilot_handbook/media/PHAK%20-%20Chapter%2003.pdf)" at sea level is defined as 15 degrees celsius (59 degrees F) with an air pressure of 29.92 inches of Mercury (Hg) {or 1013millibars}.
There are some other factors that come into play, but they are not so important for purposes of this discussion.

Air pressure decreases with an increase in altitude (the air gets thinner as you get higher).
Therefore, on a "standard day," if you are not at sea level, you will have a different, but fixed air pressure. For example, at 1,000', standard air pressure is 28.86 inches of Hg. At 3,000 feet, standard pressure is 26.82" of Hg. At 5,000', standard air pressure is 24.89" of Hg

So, we can say this another way; namely that pressure altitude is simply what your altitude would be if it were really a standard day.
If you are at sea level but the air pressure is low, say, 24.89" of Hg, than your pressure altitude is actually 5,000 feet.

The reason this is important is that when the air (or any fluid) is denser, things moving through the air are affected more by the interaction between the "thing" (that "thing" could be an airplane, or it could be a bullet heading from your muzzle to that rhino charging you at this very instant...) and the fluid through which it moves (in this case, air).

That is why some ballistic tables or programs want to know your altitude. By factoring this into the equation, they can (hopefully) be more accurate with the results of their calculations.

I hope this helps.

[Luckus]

Makes perfect sense. I had an idea about what it was, and i see how it relates to bullet flight. This rifle shooting is interesting stuff.

[jsthntn247]

65 degrees in August, I need to move up there. Good shooting too!!!

[Luckus]

It has been a hot humid summer, but the last week it's cooled down a bunch. Feels like fall, and time to hit the brush. I'll be in Wyoming after a bull October 15th. 65 and still alive, Luckus

[junkman1967]

Density altitude is simply pressure altitude corrected for non standard (59 degree) temperature.