6.5X55, 6.5-06, 6.5-06AI, & The Heavies

[RustyPin]

Whether you're shooting the Swede or the 06 or even the RWS, can the 6.5 Heavies like the 147 & 150 Grain Bullets Compete? When it comes to Windage at say 1000 Meters can a .264 Projectile do what a 185 Grain 7mm-.284 can do? Or is the 6.5 just a Lightweight? 6.5 Wby & 26 Nosler Shooters please chime in here as well. Is the 6.5mm Relegated to a short range Flat Shooting Hunter? Where is the Science?

 

[watercam]

No matter what caliber one shoots, you still have to deal with wind. There is no getting around it. Accuracy and retained velocity is what gets them to 1K. The BCs are very high for the weight of the bullets and all of the cartridges you named have been successful at that range. As soon as you get into the 26 Nosler recoil area you need to contend with being beat up over an 90 shot day of shooting in a High Power match. If it is a multi-day event multiply that by 3-5 days straight and fatigue is bigger factor.

 

[Twicepop]

It isn't just weight, it's weight per caliber. Compare the sectional density of that 185 grain 7MM bullet with a comparable 6.5MM bullet, then find the one with the highest B.C.s.

 

[CobraRed]

I send 147's 3100fps with 6.5x55AI and 140's 2980fps with 6.5x55.

Wind is certainly a factor when shooting my 1200y plates. Both bullets dance around quite a bit, but still much less than my .308. That's because even though the .308 is sending heavier projectiles, they are spending a lot more time in that wind due to slower velocities as a factor of lower muzzle velocity and lower BC's.

Now if you can get the high BC's of the 7mm to sustain that velocity, and send them with high enough muzzle velocity to best the 2900fps+ 6.5's - yes a 7mm will do better in wind. That's pretty simple math. The difference isn't night and day, however.

My 147's need about 5.5MOA per 10mph left to right at 1200 yards. A 280AI sending a 180ELD-M at 2900fps needs about 4.9 at the same range. 0.6MOA per 10mph of full cross wind is certainly a real difference, but not a "build a new rifle" difference to me. Of course you could step up to a 7mm Rem Mag and above for more juice and burn barrels to the cows come home but so can 26 Nosler.