Rob96 said:
My efficiency comment was in regards to the comparison of 270 and 308 Win. Very similar ballistics but the 308 uses less powder to achieve it which also results in less recoil.
In terms of recoil, the difference is almost entirely academic.
Using 150gr bullets and Hodgdon's data, the .270 maxes out at 2,940fps and 60.8gr (compressed) of IMR 7977. Most loads are 52-56.8gr and velocities are in the low 2,800 range. The .308 maxes out at 51.5gr CFE223 and 2,974fps. Most loads range from 44-48gr and velocities are generally mid-2800s.
If I input some of the data to handholds.com recoil calculator, using the two highest charge weights for each cartridge and a firearm weight of 7.5lbs, I get a difference of 7.8% recoil impulse, 7% firearm velocity and 16% in recoil energy, all lower for .308. (.308 has 16% less recoil energy)
However, if I happen to be loading my .270 with IMR4831 and my .308 with CFE223, I would have differences of 3%, 2.8% and and free recoil energy of 5.7%, all lower in the .270 (.270 has 5.7% less recoil energy)
Now, 16% is not trivial but we can see that I can completely change the balance by using a different powder.
So, while the .270
generally has higher recoil than a .308, the difference is usually quite small and sometimes it's not even true at all.
reynolds357 said:
All this "efficiency" stuff gets taken too far. A Prius is more efficient than my F-350. I don't intend to pull goose necks with the prius.
Yes, but we're not comparing a Prius to an F-350. This is more like a an F-350 versus a Silverado 2500. Or some other such truck... I know nothing about trucks.
Gunplummer said:
Just judging by people that show up at public and private ranges, I would have to say that the people on these "Ranch hunts" just recently purchased or borrowed the Magnums. Usually they were told they "Had to use a magnum" out west or to hunt caribou. Probably a lot of truth to that, but point being they were probably using a gun that was new to them. I ran into a bunch of guys from a shotgun area at the range one day. Some of them had never fired a high powered rifle before and apparently there was a lot of new guns in the mix. They were headed out west and the range we were at was only 100 yards.
What I'd really like to know from the guy who wrote that article (
the full article is here by the way) is what percentage of the animals that were found and didn't need tracking were shot with magnums. I'd also like to know how he defines "magnum".
I could say something like "90% of lost animals were shot with a .308" but that really only has meaning if less than 90% of ALL animals were shot with a .308. If 95% were shot with a .308 then 90% lost shot with .308 would actually mean it's performing BETTER than average but just saying "90% were with .308" sure doesn't make it sound like it.