I know these two cartidges are very close and appreciate all of the reply's in my other post. But,how do the two compare if using bullets of the same SD (or close)as far as wind drift goes at extended ranges?Thanks!

you have to ask mathman for specifics, but heavy bullets almost always best light bullets in the wind. someone may come up with an example of a light bullet beating a heavier one in the wind, but i can't think of one.

Those figures are available from many sources, most load manuals for instance. However for all practical purposes consider the difference insignificant.

Bullets of equal SD/design generally have similar BC, so my guess is .270 would win by a hair given that it will drive bullets of equal SD a bit faster and have less time of flight. Of course there are some anomolies for both where one make of bullet will show signficantly higher BC for similar SD. One example is 130 nosler (SD 242) vs 165 nosler (SD 248) partition federal factory loads:

Load No Caliber 100 Y 200 Y 300 Y 400 Y 500 Y
P270P 270 Win. 0.7 2.9 6.6 12.4 20.2
P3006AD 30-06 Spring. (7.62x63mm) 0.8 3.2 7.7 14.2 23.1

I believe bullet weight does help reduce wind drift, but fatter caliber doesn't help so may offset some in .277 vs .308. You can probably find more really heavy (200+ gr) super high SD/BC (.300+ / .500+) bullets for the .30-06 than you can for the .270 which generally tops out around 150 gr.

Lou

Sort of. It's not really about the weight of the bullet, it's about the weight of the bullet as compared to the surface area that is contacting the wind. It is true that a heavier bullet for a given caliber will be better in the wind. The best comparison that is easily used is the BC value. This takes into account the surface area of the bullet, the shape of the bullet, and the weight of the bullet.

I would say that a 150gr .270 bullet would be comparable to a 180gr .308 bullet in any given bullet design.

The only things which affect wind drift (aside from wind speed) are (a) ballistic coefficient and (b) velocity. Ballistic coefficient, of course, takes into account weight, shape, and diameter.

A 130 grain .270 bullet has the same BC as a 190 grain .308 bullet of the same shape.

You can drive a 130 grain .270 bullet over 3000 fps. You cannot do this with a 190 grain .308 bullet except possibly with a .300 Weatherby Magnum or larger case. If you drive a 150 grain .308 bullet at 3000, it has nowhere near as good a BC.

Therefore the .270 beats the 30-06 as far as wind drift, trajectory, and remaining velocity is concerned. Also, it has a lot less recoil for bullets of equal BC.

Well Guys,
Thanks for all of the reply's!I guess my mind is made up, as long as I plan on getting a new rifle, I'll go with the 270. Of course there is still the outside chance it may be a 300WSM!

30-06 drifts more, kicks more, drops more, what's not to like?

Define extended range and what kinds of targets, paper or animal?

Thx
Dober

If ya'll are worried about recoilitis from the '06, get a 270, shoot lightweight Ready Splat (tm) bullets and go forth with the rest of the ladies.

Wayne

Sorry, Bud, but all the ladies in my household shoot 30-06's -- one an old Ithaca LSA 65, and the other a LH model 70. I suggested something a little more "lady-like" and neither of them would entertain the idea. They like the way their '06's lay the moose down in their tracks.

So do I.

Close to a wash, if you compare similar sd's and bullet designs. Example from Federal Fusion ammo:


INCHES AT 10 MPH

100 y
200 y
300 y
400 y
500 y

270 Win. 130-gr. Federal Fusion (sd .242), mv=3050
0.7
3.0
7.0
13.1
21.3

30-06 Spring., 165-gr. Federal Fusion (sd .248), mv=2800
0.8
2.9
7.0
12.9
20.7