Flag Pole Height?

[gilmillan1]

how high are the flags supposed to be? we are getting ready to replace our old flags at our club and we want to go with the standard NRA flags.

 

[lawman29]

6.9 Range Safety Flag—A red flag visible from the firing line, when possible, will be displayed when firing is in progress (Recommended size of range flags is 5 ft., 9 3/8 inches. At the hoist, 18 feet in length and tapered the full length of the lower edge to be 3 feet wide at the fly end and made of red cotton flag bunting.)

6.9.1 Wind Flag—Wind flags should be displayed at various distances between the firing line and the targets. It is recommended that the flags be placed at 200, 500 and 700 yards. It is further recommended that the flag be 48 inches by 18 inches at tip and 12 feet in length. This flag will be of two colors, red and yellow.

 

[Immike]

how high are the flags supposed to be?

I can't find a official height of pole in the NRA rule book. We have all seen a variety of heights on several ranges. Most have the tails above the view of the targets.

 

[243Mendoza]

i would think that pole length should be similar to path of bullet to give useful info

 

[Keith Glasscock]

I don't think there is a standard height. Most ranges I frequent have the flags setup so they look to all be on the same horizontal plane when viewed from the firing line. On flat ranges, I've noticed that the tip of the flag typically hangs around 6' off the ground with no wind. If the flag is 12 feet long, I'm guessing that the poles are ~18 feet tall.

 

[coford]

The flag poles at our range are 20' tall - except for the one at 700 that sets in a low spot and it is on a taller pole to make it set in line with the others. We use 20' sections of pipe to make them out of.

 

[gilmillan1]

Thanks. I think we will go with 20 feet.

 

[Barrel Nut]

i would think that pole length should be similar to path of bullet to give useful info

Yeah.........that's what I would think too.
Here's an interesting exercise. Take a guess at how high above your muzzle a typical bullet rises on it's way to a bulls-eye hit at 600 yards before it arcs down to the target. Assume a flat and level rifle range.

Don't look at your ballistics calculator first............. no cheating. Just take a guess based on your intuition.

 

[Immike]

Thanks. I think we will go with 20 feet.

Pipe comes in a standard length of 21' and the black pipe is a pressure tested pipe for use in plumbing gas. You may save quite a bit if you can get untested pipe from your supplier. It comes as bare steel and will help with holding paint also.

 

[Gina1]

Just thought I would pass this on. A really great source for wind flags, check it out. Made in the USA and a good price, IN STOCK !!

http://bagsbybandy.com/nrarangeflags.html

 

[Alexander-M]

Yeah.........that's what I would think too.
Here's an interesting exercise. Take a guess at how above your muzzle a typical bullet rises on it's way to a bulls-eye hit at 600 yards before it arcs down to the target. Assume a flat and level rifle range.

Don't look at your ballistics calculator first............. no cheating. Just take a guess based on your intuition.

I have heard several shooters discuss this topic, and they all agree that the flag would provide more useful information if its height were close to that of the trajectory of the bullet. However, estimates of what the trajectories are varied appreciably, and all appeared to me to be too high, so I calculated what the trajectories may be for .308 185-gr Juggernauts at a reasonable 2750 fps.

The plots below show the trajectories of the rifle sighted in at 100 yards, to represent the drops at 600 and 1000 yards, as well as the rifle sighted in at 600 and 1000, to show how high the trajectories are when shooting at those targets.

As can be seen, the bullet drop at 600 yards is approximately 7 feet when zero is set at 100 yards, and the trajectory will reach a maximum height of approximately 2-1/2 feet when shooting at a target 600 yards away. The equivalent drop and maximum height for a 1000-yard range are approximately 27 feet drop, and maximum trajectory height approximately 9 feet.


The problem is, of course, that if the flag poles were that 'short', flags that could be seen at a distance would drag on the ground. Hence, the flag poles have to be high enough to allow the flags to fly freely and be seen.

Alex

 

[Barrel Nut]

...... snip ...........estimates of what the trajectories are varied appreciably, and all appeared to me to be too high, so I calculated what the trajectories may be for .308 185-gr Juggernauts at a reasonable 2750 fps. .......... snip.........

Nice charts showing that the apogee is somewhere around three feet above the muzzle (depending on caliber, MV, BC, etc.) for most 600 yd shooters and roughly ceiling height for those who shoot at 1000 yards. I also have talked to experienced shooters who think it's quite a bit higher than that.

Most often people take the "drop" to be the same as the height above muzzle when the zero is changed from 100 yards to a much longer range. In fact, the apogee is roughly a third of that.

There's not much that we can do about the ballistic laws of nature and constraints of our typical wind flags except to be aware that dialing in a windage correction for the first sighter based on a wind flag on a 20 foot pole is likely to be too much. It took me a while to figure that out.

 

[XTR]

We put up new 40 footers (at considerable expense) at the 600 yard line in Oak Ridge 2 yrs ago, but you are shooting over a valley there. It's in an effort to get the flags up in the wind for shooting from 1000 yards and not below the tree line on the sides of the range. The flags on those poles are probably still at or below the bullet path.