craigrowe58
Member
What kind of velocity can a 30" barrel produce with a tight necked long throated 308 Win??
Velocity with a 168 & 175 gr bullet
- Thread starter craigrowe58
- Start date
QuickLoad
Using QuickLoad, I found that 44 gr of VARGET should result in a velocity of 2787 fps out of a 30" barrel using the 175 gr SMK.
Using QuickLoad, I found that 45 gr of VARGET should result in a velocity of 2853 fps out of the same 30" barrel using the 168 gr SMK.
Both loads are predicted to be just under the maximum SAAMI pressure of 60191 psi but this is a prediction, not an observed and measured load.
BUT REMEMBER, the 168 gr SMK was never intended to shoot supersonic out to 1000 yards.
As always, work up to max loads slowly.
Hope this helps,
George
Using QuickLoad, I found that 44 gr of VARGET should result in a velocity of 2787 fps out of a 30" barrel using the 175 gr SMK.
Using QuickLoad, I found that 45 gr of VARGET should result in a velocity of 2853 fps out of the same 30" barrel using the 168 gr SMK.
Both loads are predicted to be just under the maximum SAAMI pressure of 60191 psi but this is a prediction, not an observed and measured load.
BUT REMEMBER, the 168 gr SMK was never intended to shoot supersonic out to 1000 yards.
As always, work up to max loads slowly.
Hope this helps,
George
E
earl39
Guest
as usual
George is correct but, and there always seems to be a but in there somewhere, with the slow lots of Varget still out there speeds and pressure will vary. With the lot i have i am getting 2920 fps with smk 175's measured with a chrony 15 ft from the muzzle and this also matches my comeups for 1000 yards so it is close. I am just starting to show pressure signs on the primer, not flat but you can tell it is wanting to. When i went up another half grain i had flat primers. I will tell you that I am over max book load so each gun is a rule into itself. I have about a pound left then it is open a different lot and start all over again. In the interest of keeping everyone safe i will not tell the load but will tell everything else. The only real way to know what your gun will do is try it CAREFULLY!!!!!!!
Savage 12 target action with McGowen barrel
Lapua brass cci br2 primers Varget powder smk 175
and a driver that needs lots more practice.
Gary
George is correct but, and there always seems to be a but in there somewhere, with the slow lots of Varget still out there speeds and pressure will vary. With the lot i have i am getting 2920 fps with smk 175's measured with a chrony 15 ft from the muzzle and this also matches my comeups for 1000 yards so it is close. I am just starting to show pressure signs on the primer, not flat but you can tell it is wanting to. When i went up another half grain i had flat primers. I will tell you that I am over max book load so each gun is a rule into itself. I have about a pound left then it is open a different lot and start all over again. In the interest of keeping everyone safe i will not tell the load but will tell everything else. The only real way to know what your gun will do is try it CAREFULLY!!!!!!!
Savage 12 target action with McGowen barrel
Lapua brass cci br2 primers Varget powder smk 175
and a driver that needs lots more practice.
Gary
O
Oaken
Guest
This is the first set of figures with my new rifle, the aim being to compare the velocities I can get out of a 30" barrel compared to load data in the manuals. I hope you find my first post usefull.
F/TR 30” 1:12 Varget, Lapua, Remington 9.5
All seated .010 off lands
Regret only one shot recorded with each load so take velocity as a rough guide only and to cover myself, work your loads up checking for pressure signs.
155gr Lapua Scenar BC .508
40gr 2660fps
41 2715
42 2775
43 2811
44 2881
45 2929
46 2993
155gr Sierra Match King BC.443
43gr 2704fps
44 2777
45 2843
46 2884
47 2993
168gr Sierra Match King BC .447
41gr 2636fps
42 2681
43 2739
44 2787
45 2840
168gr Berger VLD BC .512
40gr 2521fps
41 2638
42 2711
43 2758
44 2790 (flattened primer)
175gr Sierra Match King BC .496
40gr 2596fps
41 2640
42 2684
43 2705
44 2774
45 2792 (flattened primer)
Further experiments have produced one hole, 100yd groups with VLD@40.4gr closely followed by 175SMK@41.5gr.
Oaken
F/TR 30” 1:12 Varget, Lapua, Remington 9.5
All seated .010 off lands
Regret only one shot recorded with each load so take velocity as a rough guide only and to cover myself, work your loads up checking for pressure signs.
155gr Lapua Scenar BC .508
40gr 2660fps
41 2715
42 2775
43 2811
44 2881
45 2929
46 2993
155gr Sierra Match King BC.443
43gr 2704fps
44 2777
45 2843
46 2884
47 2993
168gr Sierra Match King BC .447
41gr 2636fps
42 2681
43 2739
44 2787
45 2840
168gr Berger VLD BC .512
40gr 2521fps
41 2638
42 2711
43 2758
44 2790 (flattened primer)
175gr Sierra Match King BC .496
40gr 2596fps
41 2640
42 2684
43 2705
44 2774
45 2792 (flattened primer)
Further experiments have produced one hole, 100yd groups with VLD@40.4gr closely followed by 175SMK@41.5gr.
Oaken