Originally Posted by 10gaugemag
Originally Posted by Riflehunter
Originally Posted by 10gaugemag
Originally Posted by Riflehunter
If you are comparing the performance of the 6.5CM to the .270 over normal hunting ranges , here are a few points to factor into your calculations:

1. Use a well-constructed hunting bullet that you can shoot through the shoulder of a deer without it blowing up before getting to the vitals, perhaps compare the 140 grain Accubond or TGK in .270 to a similar CM bullet
2. Use a muzzle velocity that a temperature stable powder gives you such as H4350 or H4831sc that will work well at -4 degrees to 100 degrees without significantly affecting your velocity , pressure and point of impact
3. Use the same length barrel 22" to 24"
4. Do not use a 200 yd zero. Sight your .270 in for 3" high at 100 yds and the CM for the same.
5. Use your accurate load of temperature stable powder which gives a moderate pressure, not the exaggerated published loads of factory loaded ammunition, nor maximum load
6. factor in that the .270 has 10 % more cross-sectional area than the 6.5 for a bigger wound channel
7. Give drop figures at 100 (+3"), 200, 300 , 350 yds
8. State what loads, projectile, barrel length you are using





.277 vs .264 is only about 5% larger unexpanded, same if you use 1.5x for expanded differences.
10.24 % difference in cross-sectional area using formula pi x radius squared...... .0547 square inches for 6.5 (.264") v .0603 square inches for .270 Win (.277")

You got me there. Still not enough to make a real difference in wound channel.

Bullet construction/design would make more of a difference but then it's hard to make an apples to apples comparison on that because 1 make/model can be softer/harder or have different jacket thickness in different calibers.

Accubond in .277 140 may expand more or less easily than .264 140 grain Accubond.

Shoot a deer through the shoulders with any hunting bullet in either cartridge and he will be dead in the shadow where he stood at the shot.

It's all just a pissing match.

.264 lovers won't budge and neither will the .277 lovers. Myself I don't have a rifle chambered in either caliber.

Critters on the other hand can't tell 2 fugging bits difference when hit by either one.


All very true, assuming both bullets hit the same place with requisite impact velocity to expand and penetrate. I've seen enough BG animals killed with both the .270 Win and the 6.5 CM to come to the conclusion that between the two, the cartridge makes essentially zero difference when it comes to terminal performance, and bullet selection dominates that arena. The biggest challenge, and most important factor, in cleanly/quickly killing critters is getting the bullet to hit the right place, and that's where advantages in external ballistics come into play.