1Yogi

I was wondering what round from the 7.62mm diameter rounds has the flatest trajectory.
I believe a 30.06 is a flatter trajectory than the 308, where does 300 WinMag rate?

frizzellr

The difference between the 308 Win and the 30-06 is debatable. Much depends on barrel length and load. I believe the flattest now is the 30-378 Weatherby, but I have heard rumors of a new monster 30 from Lazzeroni that will push a 150 grain bullet over 4000fps.

biscuit jake

1Yogi perhaps you meant 7.62 (ie .308) bullets? The flatter shooting bullets have a higher ballistic coefficient. You can often find that figure as you look at cartridges and ballitstics on ammo maker's websites. Some cartridges can handle longer bullets because of the length of the neck on the case. Eg, it is easier to put a long heavy bullet in a 3006 than a 308 Winchester. Check out the ballistics tables. Get a picture of what you see as "flat" and enjoy!

God gave Americans the .30 Cal. He was right!

chuck403

Assuming that all are shooting the same weight of bullet, trajectory wise, the 30-06 is flatter than the .308. The 300 Win mag is flatter than the 30-06.

BeltedMag

Seems to me like the .308 would be flatter shooting than the .06. I mean it is used in military and police sniper rifles and used to be very popular in long range shooting matches. Must be pretty flat shooting to be trusted for those purposes, but then again that may just be because it has less felt recoil than the .06.

Nomercy

The .308win is used in sniper rifles, first by military snipers, because of the weight of the rounds. You could carry more ammo for the same weight, or the same ammo for less weight...and the difference in trajectory was small enough that the portage issue was worthy...LE agencies picked up their sniper rifles from military suppliers, until it became popular enough that they didn't HAVE to buy them this way...there are several arguements that the .308 is a better "sniper round" than the .30-06, short action vs. long, lighter recoil, lighter rounds, less powder, same effective range....and I'm sure I'm forgetting a great deal...Of course, there are at least three other (4 total) common "sniper" rounds used today, even within the same regiments and by the same snipers, the .223 in the accurized M-16, the .308 in accurized M-14's and 40X's (and other bolt rifles), the .338Lapua, typically in an AR-30, and the .50BMG in the AR-50 (military version).

If I'm not mistaken, the weatherby is considered to be the flattest shooting, which is occasionally incorrect. Flatness of trajectory, assuming the same bullet is used, is dependant upon one thing, velocity...the faster a cartridge can push it out there, the less it falls per x number of feet traveled horizontally...the weatherby is typically the fastest, with MANY rounds very close behind, but not many that people are familiar with (lazzeroni, patriot, dakota, even the RUM and WM/WSM). Occasionally, the weatherby gets passed up in certain guns/loads by other rounds, maybe not all the time, but it does happen in specific scenarios.

However, with the .300/.308mags, you're paying for the SLIGHTLY flatter trajectory, and paying dearly. As far as the effective range for most hunters, there's nothing you can do with a .30-378 that can't be done just as well with a .308 (they've both typically got ample power at any given range to get the job done, but you're not likely to get either of them on target past 1000yrds anyway!!!) but the faster/flatter the round, the more it kicks (with the same bullet weight/type), the .308 is one of the most shootable rounds you'll ever handle, while the .30-378 is getting uncomfortable for even the most seasoned of shooters.

A great trade off, probably the most efficient "hyper .30" in my opinion, is the .30-06 Ackley Improved...outstanding "wildcat", considerably more potent than the .30-06, but not much more hard recoiling.

Briman

In a high end carefully made sniper rifle, the .308 is alot more accurate than the 30-06, in a typical mass produced hunting rifle, you will probably never see the difference.

When you are talking about accuracy, flat trajectory does not necesarily equal accuracy. Some of the most accurate ultra long range rifles in the world are chambered in .50 BMG, which fire projectiles with about the same velocity as a .308. What extra velocity does do, will all else being equal, is decreases wind drift and drop.
The 30-06 only give you about 100 fps advantage in velocity over the .308. For the effective hunting range of either cartrtridge this means very little in difference in trajectory or ability to kill.

If you know the 'come ups' for your sights for a given range and know the range at which you are shooting, extra velocity doesn't matter much.