311 yard MPBR for .204 using factory or handloads?

[1858rem]

copied this copy of a copy to here

The latest Reloading Guide by Australia's premier reloading guru has just been released; Nick Harvey. He has been reloading for 50 years and been writing about it for almost as many. Many of your (U.S.) top hunters and hunting writers have hunted and spent some time with Nick Harvey. In his latest reloading guide, as usual he lists the Maximum Point Blank range for all popular varminting cartridges. What is Max. Point Blank Range? It is a distance from the muzzle where your bullet doesn't rise nor fall more than 2 inches, meaning an animal with a "vital area" of 4 inches, say a fox, can be hit by putting the crosshairs right on him and shoot, anywhere within the M.P.B.Range. For example: a .22 hornet (45 grain bullet) sighted in at 165 yards has a point blank range of 190 yards. It will be 2 inches high at 102 yards and 2 inches low at 190 yards. He lists all popular cartridges from.17 Rem. through to .270 Win. shooting a 100 grain bullet for varminting work. As a comparison:
.204 Ruger 32 grain = M.P.B.Range 312 yards (sight in at 270 yards)
.204 Ruger 40 grain = M.P.B.Range 311 yards (ditto)
.223 Rem. 40 grain = M.P.B.Range 266 yards
.22/250 40/60 grain = M.P.B.Range 287 yards
.220 Swift 60 grain = M.P.B.Range 289 yards
.223 WSSM 55 grain = M.P.B.Range 305 yards
.243 WSSM 55 grain = M.P.B.Range 301 yards
.257 Wby. Mag. 87 grain = M.P.B.Range 312 yards

id suppose this is using factory ammo, but with a claimed 4225 32g load and 3900 40g load from hornady, that would be tough to match, although most of what i have seen regarding actual chronoed numbers shows 100-150fps less than claimed.....so does hornady base there trajectory off actual testing with real guns and ammo, or run it through a ballistic program and use calculated numbers?

so far im under max and near hdy 40g load velocity that is stated on the box, but did not know what they based the trajectory on, before i go zero at 270 hoping for +/-2" all the way to 311yds, and be more like +/- 2.5-3" that im figuring off handloads.com calculator....and even entering the 3900 claimed fps, it only calculates a 2.3+/-" zeroed for 270yds



^^^so whats this based on?^^^

 

[rcmodel]

All the published trajectory tables are based on an imaginary Ballistic Coefficient of the bullet, at a imaginary velocity. They use a little science, and a little fiction.

So they are Science Fiction in the real world where the bullet hits the rifle range.

It used to all be done with a slide rule, but now they use computers.

Nobody shoots long range to get actual real data because they don't have the resources or the time to do it. But even if they did, it would still be slightly wrong with your rifle because it is not going to be the same rifle they used.

Still, it is close enough for our use, which is to compare different bullets performance at different ranges.

rc