I have found that shooting across pavement will provide a flat trajectory for almost any rifle.

The fastes bullit that I have ever fond is th 30/06 with a acsellarater sorry about the spelling but it is 4080 fps out of a 22inch berrel

Now that we have made the circle, the flatest shooting most reasonable priced and easiest to find ammo for and will cover all the average hunters needs would be a 22-250 and a 270 Win. You can go hotter and more expesive but why would you need to. Flat shooting and tons and tons of energy don' t kill a thing that the old standards won' t for a fraction of the money. They also won' t turn the average hunter into a super marksman who can take any practical advantage of such ballistics.

Dont forget the Porsche 928 S4
Released in 1987 as the fastest production car. Production car means you go to any dealership and the car is on the lot. You pay and you drive.

A heavy ass car with power leather interior, cruise control....you can drive it for days and never get tired....not to mention it will do 171 mph without feeling like you are driving in a truck.

Ok I' ve been doing some research myself on this flattest tragectory.

In a 7mm STW with 120grain zeroed at 100 you get a 27.0 inch drop at 500.
In a .243 with 55 grain zeroed at 100 you get a 29.1 inch drop at 500


.220 swift = 33.8 inch drop at 500 with 40 grain bullet, the weakest 1457 fps
.22-250 = 32.7 inch drop at 500 with 40 grain bullet, the fastes 4150 velocity
.243 = 29.1 inch drop at 500 with 55 grain bullet
.257 wby = 30.1 inch drop at 500 with 87 grain bullet
.270 wby = 32.3 inch drop at 500 with 100 grain bullet
.300 wby mag = 31.9 inch drop at 500 150 grain bullet, the stongest 4316 fps
7mm STW = 27.0 inch drop at 500 with 120 grain bullet
7mm STW = 31.3 inch drop at 500 with 140 grain bullet, the slowest 3500 velocity
6mm Rem = 30.2 inch drop at 500 with 55 grain bullet

i knw for a fact the 300 ultra mag is flatter shooting than all other ultra mags.but i think the 30-378 is the flattest.

and to whoever said that the 257 can kill a deer at 500 yards does not know what he is talking about.Any gun can kill a deer that far holding right on but you will have to zero it in at that range.no gun can be zeroed in at 150-200 yards and hit a target at 500 holdin right on.maybe .50 bmg.

Footballboy5571-As the owner of two 300ultramags and a 7mmultramag I can tell you that with equal barrel lengths the 7mmultramag will shoot slightly flatter than the 300ultramag.The 300ultramag does however carry more energy.

lol, the 50? " BOY" you need to spend some more time readin ballstics I reckon. The 50 has HORRIBLE ballistics when compared to most SuperMags. The saving grace of the 50 besides its AWESOME power is its accuracy, penetration and wind-drift defying heavyweight bullets.

BTW the 30-378 AINT the " Top Dawg" on the block!
RA

Out of factory and affordable rifles the flatest shooting would probably be the 7mm Remington Ultra Mag.

The 257 WM and 30.-378 WM would also be right there.

I believe 1 of the flatest shooting caliber/cartridge in the world would have to be the 6.5mm/50 BMG. Not sure how long the barrel would last though??