Max range for a .300 whisper...?

[Tiffy]

Was just feeding some info into a ballistics programme and it showed my .300 whisper still doing 400fps at 3000m. which I find hard to believe, a drop of 600 fps over 3km?

Anyone have some data on this?

Cheers

[320pf]

Tiffy,

Here is a link to p pretty good article on the 300 Whisper:

http://www.lasc.us/RangingShotLongWhisper.htm

Your ballistic calculations are correct. J.D. Jones picked up on the fact the sub-sonic high BC bullets do not loose much of their velocity and are less influenced by wind drift.


320pf

[lemmethink]

Just for the hell of it last summer I shot my 300 whisper out to 850 yards. I had to crank the elevation all the way up on the 10x super sniper and still hold over about 4 or maybe 5 dots IIRC. It was a lot of fun as the flight time was a couple of seconds.

I just went to the JBM ballistics sight and punched in a generic 30 cal, 220 gr, 0.5bc bullet travelling at 1000fps muzzle velocity. The "maximum distance" calculator gave a terminal range 4083yds, initial angle 37.5 degrees, terminal angle 56.4 degrees, terminal velocity of 466fps, and a flight time of 28.2 seconds!!! Pretty amazing for a little whisper to carry that far and for such a long hang time. Anyone want to help me figure out a way to test it???

[cr500]

I have read about some people shooting gongs (and a ground hog) with 308s at 3000+ yds, using special scope mounts. Maybe with a Whisper, you could take the shot, hop in the car and drive up to watch the impact.

[jarhead1086]

http://accurateshooter.wordpress.com...ra-long-range/

I never thought of using these for the Whisper, they are high end. If you want cheaper just for grins you can try the external adjustment base that Leatherwood makes.

[interceptor]

Is anyone out there in Whisper land using a 20MOA base for distance rather than cranking on your elevation turret so much?

[lemmethink]

I haven't shot it over 300 yards for a while but I was using a 20 moa base, maxing out the turret and still holding over to get to 850 yards last year.

[kalikraven]

It's a rifle not a Mortar..... LOL

[interceptor]

Originally Posted by kalikraven

It's a rifle not a Mortar..... LOL

Dude, ROTFLMAO!

[LouBoyd]

Here's a comparison of three rifles and cartridges shooting the same 220 grain Sierra Matchkings at 1000 yards.
The first is a 30" barrel 300 Remington Ultra, The second a 24" 30-06 and the third a 16" 300-221 loaded subsonic. The others are loaded for about 90% of SAAMI max presssure.
The listed values are:
MV = Muzzle Velocity fps
ME = Muzzle Energy ft-lbs
TV= velocity at 1000 yards fps
TE = energy at 1000 yards ft-lbs
%E = percentage of original muzzle energy remaining at the target
TF = Time of flight in seconds
DM drop from 100 yard zero minutes of arc
WM wind drift for 10mph crosswind in minutes of arc

Cartridge MV.. ME TV TE %E TF DM WMOA
300Rum 3000 4795 1811 1747 36 1.29 22.4 4.82
30-06 .. 2500 3330 1440 1105 33 1.58 34.4 6.45
300-221 1000 533 795 336 42 3.40 178.6 6.68

The numbers speak for themselvs. The only thing most people find surprising is that the subsonic wind deflection is very reasonable. Drop due to gravity is predictable but is very sensitive to time of flight which is dependent on muzzle velocity. Velocity deviation is the the most important factor in loading subsoinc ammo for long range. Benchrest loading techniques are necessary or vertical stringing will kill accuracy. A laser rangefinder and target knobs are a necessity too. Drop increases exactly with the square of the time of flight.