Dear Ron: What’s the flattest shooting rifle?

Aug 6

Q: Ron, I would love to see you do a video on the all-time flattest shooting rifle. Is it a 7mm rem mag, a 270, a 300 win mag, a 30-06?

A: Kelly, it depends on the distance across which you want to measure. In general, lightweight bullets driven very fast shoot flatter than heavier bullets with better aerodynamics (high B.C. rating) driven more slowly. Beyond 600 or 800 yards, however, the efficiency of the high B.C. projectiles begins to add up and they shoot flatter at extreme range.

*Could the 6.5 Creedmoor, 6.5 PRC, or 26 Nosler be the flattest shooting cartridge?*

Muzzle Velocity & B.C. Determine Flattest Shooting Cartridge

We really needn’t measure individual cartridges/bullets because just two things determine drop: muzzle velocity and bullet B.C. Match those and regardless of caliber, drops will be identical. So, to find the world’s flattest shooting cartridge, find the best combination of fast MV and high B.C. Here are some examples shot dead flat, meaning the bullet departs the muzzle perfectly horizontally with no sight angle above the bore. Pure drop from the get-go. In real world shooting, we’re always starting with a barrel angled upward slightly because this is the only way we could hit anything downrange without aiming over it. But with this dead-flat launch angle we get an accurate picture of pure drop.

Drop Chart Shows Flattest Shooting Cartridge

Cartridge	Bullet/B.C.	MV	600 yd drop	1,000 yd drop
6.5 CM	143-gr. /.625 BC	2,750 fps	104”	350”
270 Win.	150-gr. /.590 BC	2,900 fps	95"	319”
7mm RM	175-gr. /.648 BC	2,900 fps	93”	305"
220 Swift	40-gr. /.220 BC	4,200 fps	70”	373”
338-378 Wby	300-gr. /.826 BC	2,800 fps	95”	299”
50 BMG	750-gr. /1.05 BC	2,700 fps	98”	301”

These numbers indicate that one of the flattest shooting commercial cartridge at sensible hunting ranges is the 220 Swift. If you think that’s the product of the latest technology, know that Winchester introduced this cartridge in 1935! But the 220 Swift is not a legal big game cartridge in many states and the 40-grain bullet is a poor choice for big game where the Swift is legal. Heavier bullets in the Swift, however, were lauded in the mid-20th century as incredibly effective, quick killers by animal damage control shooters who were culling destructive, invasive feral burros and horses from Grand Canyon National Park. (Yes, our govt. was once sensible enough to try eliminating invasive species from public lands instead of spending millions to protect and increase them.) Many western hunters still swear by the 220 Swift as a pronghorn and mule deer round.

Here’s your winner. At least inside of 600 yards. It’s the little 220 Swift (center) pushing a 40-grain bullet! The 264 Win Mag. and 7mm RUM might come close with the right bullet. Worth a look anyway.

Kelly, I did not take the time to research and compare every cartridge in the world that I thought might win this flat trajectory contest, so you might find another. The 204 Ruger can come close. The 223 WSSM might even beat the Swift, although it’s nearly obsolete already. There may be others like the 257 Wby. These days the 26 Nosler and 6.5-300 Wby. are shooting remarkably flat. Ditto some of our fastest 7mms and 300s. Finally, there are the really big, long range specialty cartridges like 408 CheyTac and 416 Barrett, but I don’t consider those sporting hunting options. Big, heavy rifles, lots of recoil. But flat? Oh yeah. Perhaps you or other readers here can find the ultimate winner! But I suspect the 220 Swift will hang on as our Flat Trajectory Champ or close to it at quasi-sensible hunting distances.