6.5-338?
- Thread starter furtaker
- Start date
DAVID NANCARROW
New member
Heard of it....boy-howdy, talk about a barrel warmer!
DAVID NANCARROW
New member
never have seen that 264 Win mag, but that sure seems like a lot of powder behind a tiny bullet.
Ummm, 7.62 08? Are you talking 7.62x51 NATO, aka 308 winchester?
Ummm, 7.62 08? Are you talking 7.62x51 NATO, aka 308 winchester?
.264Win has a case water capacity of 82 gr h2o. For comparison, 6.5-08 is 56, 6.5-284 66.
Taking the average of the fastest loads with a max pressure of 60k psi from QuickLoad with a 139gr bullet, here is the data for h2o capacity vs. muzzle velocity:
.260/6.5-08 - 56gr h2o - 2890 fps
6.5-284 - 66gr h2o - 3091 fps
.264 win mag - 82gr h2o - 3160 fps
theoretical - 92gr h2o - 3200 fps
Going from the .260 case to the 6.5-284 case you get about 20 fps per gr h2o of case capacity. From the 6.5-284 case to the .264WM case you get about 4 fps per gr of h2o capacity. Clearly it's past the tradeoff point where more case capacity given the bore size makes sense.
-z
Taking the average of the fastest loads with a max pressure of 60k psi from QuickLoad with a 139gr bullet, here is the data for h2o capacity vs. muzzle velocity:
.260/6.5-08 - 56gr h2o - 2890 fps
6.5-284 - 66gr h2o - 3091 fps
.264 win mag - 82gr h2o - 3160 fps
theoretical - 92gr h2o - 3200 fps
Going from the .260 case to the 6.5-284 case you get about 20 fps per gr h2o of case capacity. From the 6.5-284 case to the .264WM case you get about 4 fps per gr of h2o capacity. Clearly it's past the tradeoff point where more case capacity given the bore size makes sense.
-z