That will be a nice combo in a carry rifle platform with low recoil.
6.5 Osprey Mag Photo
- Thread starter 03Rick
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That will be a nice combo in a carry rifle platform with low recoil.
calib
Well-Known Member
interesting round, but when you talk about the 7-300 win you don't mention the 180 berger at all and that is what most of us are shooting in them look up a 180 at 3150to 3175
Based on my ballistic software a 7mm 300 Win. Mag. shooting a 180 grain Berger out of a 26" barrel at 3175 fps., would need a load of 75 grains of N165 and the pressure is a whopping 57,950 CUPs or 69,500 psi. which is well over the 50,100 CUP or 58,500 to 59,000 psi. baseline I am using for extended barrel life. The recommended psi for the 7mm Rem. Ultra Mag. is only 65,000 psi. I am curious as to how long a barrel will last at that pressure level?
So comparing the 6.5 Osprey Mag. to the 7mm300 Win. Mag. for target purposes would be as follows:
180 grain 7mm Burger target bullet @ 3175 fps = 189" drop at 1000 yds. and a wind drift, with a 10 mph cross wind, is 52" Using 180 Sierra hunting bullet the drop at 1000 yds is 191" and a wind drift is also 52" .
160 Grain 6.5mm Matrix hunting bullet @ 3125 fps = 194" drop at 1000 yds. and the wind drift with a 10 mph cross wind is also 52".
The 6.5mm loaded to 59,000psi has the same wind drift at 1000 yds as the 7mm loaded to 69,500 psi and only 4 or 5" more drop.
Using a 9.5 lb rifle in this example the felt recoil comparison is as follows:
180 grain 7mm @ 3175 fps the felt recoil energy = 25.3 ft-lbf.
160 grain 6.5mm @ 3125 fps the felt recoil energy = 21.3 ft-lbf.
As I mentioned before this rifle/caliber combo was designed for long range hunting of deer and antelope however the 160 grain Matrix, with a BC of .685, pushed to 65,000psi would yield a velocity of 3275 and would match that of the 7mm 300 for elk or moose hunting out to 1000 yds.
7mm 180 grain Sierra = 1356 ft lbs. terminal energy
6.5mm 160 grain Matrix = 1355 ft lbs. terminal energy
With all this said, there is no doubting that the 7mm 300 Win. Mag. is a fine cartridge.
So comparing the 6.5 Osprey Mag. to the 7mm300 Win. Mag. for target purposes would be as follows:
180 grain 7mm Burger target bullet @ 3175 fps = 189" drop at 1000 yds. and a wind drift, with a 10 mph cross wind, is 52" Using 180 Sierra hunting bullet the drop at 1000 yds is 191" and a wind drift is also 52" .
160 Grain 6.5mm Matrix hunting bullet @ 3125 fps = 194" drop at 1000 yds. and the wind drift with a 10 mph cross wind is also 52".
The 6.5mm loaded to 59,000psi has the same wind drift at 1000 yds as the 7mm loaded to 69,500 psi and only 4 or 5" more drop.
Using a 9.5 lb rifle in this example the felt recoil comparison is as follows:
180 grain 7mm @ 3175 fps the felt recoil energy = 25.3 ft-lbf.
160 grain 6.5mm @ 3125 fps the felt recoil energy = 21.3 ft-lbf.
As I mentioned before this rifle/caliber combo was designed for long range hunting of deer and antelope however the 160 grain Matrix, with a BC of .685, pushed to 65,000psi would yield a velocity of 3275 and would match that of the 7mm 300 for elk or moose hunting out to 1000 yds.
7mm 180 grain Sierra = 1356 ft lbs. terminal energy
6.5mm 160 grain Matrix = 1355 ft lbs. terminal energy
With all this said, there is no doubting that the 7mm 300 Win. Mag. is a fine cartridge.
calib
Well-Known Member
Thanks for the great report with number comparison. That is a appealing round for sure.
