Ram-linel Trajectory Angle

[DanDeMan]

Meine Damen und Herren,

I was hoping that another poster would delve into the trajectory-angle issue from the perspective of the optical illusion that leads spotters to think the bullets are "dropping out of the sky" (steep trajectory angle) as they approach rams. When light conditions are "right" and the spotter/coach has a quality scope we often see the bullet's glint as it "drops" into the rams. I know what it looks like, as well do many of you. It looks like the bullets are really dropping at a steep angle. But, the bullets are only dropping about 3 feet over the course of the last 554 feet to the rams, in about 4/10ths of a second. We don't "see" the 554 feet that the bullet dropped over, only that it dropped about 3 feet in 4/10ths of a second. And that, Meine Damen und Herren, is where the belief that bullets shot at rams are coming in at steep angles. Oh, this analysis was done using the "rainbow trajectory" of the 7mm, 168 SMK launched at 2,400 fps.

[DanDeMan]

I should've added to the above post that if the 3' drop over 554' is trig'ed out, the angle is 0.3 degrees. Of course that is only a crude, linear approximation because a line tangent to the trajectory becomes increasingly steeper in the downward direction past the trajectory apex, at about 275 meters down range.

[Jerry G]

I'll have to go along with Dan on calculation the angle. I haven't run the numbers but the method is solid.

[Taps]

G'day Folks,
As an aside to the topic, I recently spent some time in the butts at a long range "Buffalo Rifle" shoot down here in Australia. We shot from 1000, 800, and 600 yards. Targets were on a 6ft square frame, the bottom of which was about 7ft from the ground when standing behind the mantlet. Shots from 45/70s that went through centre of the target (i.e about 10ft above our feet level), would hit the stop butt about 3ft from the bottom. This was roughly 15 yds from the target frame. So a 7ft drop over 15 yds was a pretty steep trajectory. This was my first experience at this end of a rifle range and certainly an eye opener! We had one shooter firing a 45/120 and from 600 his shots were supersonic and only landing about a foot below the impact zone of the Fullbore rifles that predominantely use this range.
Taps

[DanDeMan]

Taps,

Do you shoot with my Aussie buddy Bruce Moulds? He's into BPCR as well as FullBore.

[Jerry G]

If you have ballistic software, run a drop table in 10 M incriments near the ram distance. Just for the hell of it, I looked at my 300 WM and the drop from 475 M to 500 M (25 M) is 8 inches. Go figure.

[Taps]

G'day from the Game Ranch,
DanDeMan, no I don't know your mate Bruce but you could have a look at my post in Blackpowder about a match I am running in August and let him know. More shooters are welcome as always. We had a great time at the first one last year and looking forward to the"Return".

Taps

[malinois]

The rounds look like they are dropping out of the sky if the targets are lower than the firing line as it sometimes is and the berms are a bit back from the target line...so if you bearly miss the top of the animal the impact will sometimes be behind the animal out of the line of sight. its a neat sight to see...lol until they put that big zero on your score card.

[Jerry G]

If the berm is 20 feet behind the ram, the bullet will dcrop about 4.2 inches. So, if the berm is only 10 feet behind the ram, the bullet will drop 2.1 inches. That ain't a lot, in fact that ain't much. We could quibble about fractions of an inch because I used 1 degree of drop, not 0.7 degree. Seems like it takes a 'near miss' for the bullet to be behind the ram just a little.