TheDerkster
Well-Known Member
It just hit me when i chrono'ed the 7mm SS the other day. A 195 eol with 59 gr of R26 which was great on accuracy was pushing past 2900 fps. The ones i tested averaged around 2920-2930. The temperature was around 65 degrees. I didn't hit major pressure signs till around 61.5 to 62 gr of powder. This is a 28 inch krieger.
In contrast, Ive been looking up what people are using as their long range 300 win mag loads. It seems that something like a 210 Berger VLD with 79 grain of H1000 @ 2990 fps is about the best ive found. Of course this is using ACCURATE loads. Not maxing out the velocity. Shooting it at 3100 fps just because doesn't count. Id probably be pushing 3050' if i added that other 3 grains of powder again, but I get primer back flow and ejector marks.
So I guess what im getting at is I dont understand how it does it? 20 grains less powder and only 15 grain lighter, yet still almost at the same velocities comparatively.
I punched everything in to JBM keeping everything constant such as weather, etc except the bullet and velocities. My current set up with the 7mm SS will surpass that 300 win mag load i just mentioned at 700 yards as far as energy is concerned. At 700 yards, the 7mm will have 2002 foot pounds, where as the 300 win mag will have 2000. And the gap just gets wider from there. The drop stays within .1 moa until 700 yards and then the 300 mag starts to fall more quickly. Most of the at distance stuff has to do with ballistic coefficients because the 195 eol is extremely efficient and stream lined.
Still, it just baffles me how efficient that cartridge is. I was just thinking about buying a 300 win mag, but whats the point? I basically have one. Past 700 yards, im putting out more energy anyways. Before that, the numbers are still close. I guess ill just have to go build that 338 lapua and get my 6.5 creedmoor in an AR10 platform and call it good. Or maybe a 20mm as well but thats expensive.
In contrast, Ive been looking up what people are using as their long range 300 win mag loads. It seems that something like a 210 Berger VLD with 79 grain of H1000 @ 2990 fps is about the best ive found. Of course this is using ACCURATE loads. Not maxing out the velocity. Shooting it at 3100 fps just because doesn't count. Id probably be pushing 3050' if i added that other 3 grains of powder again, but I get primer back flow and ejector marks.
So I guess what im getting at is I dont understand how it does it? 20 grains less powder and only 15 grain lighter, yet still almost at the same velocities comparatively.
I punched everything in to JBM keeping everything constant such as weather, etc except the bullet and velocities. My current set up with the 7mm SS will surpass that 300 win mag load i just mentioned at 700 yards as far as energy is concerned. At 700 yards, the 7mm will have 2002 foot pounds, where as the 300 win mag will have 2000. And the gap just gets wider from there. The drop stays within .1 moa until 700 yards and then the 300 mag starts to fall more quickly. Most of the at distance stuff has to do with ballistic coefficients because the 195 eol is extremely efficient and stream lined.
Still, it just baffles me how efficient that cartridge is. I was just thinking about buying a 300 win mag, but whats the point? I basically have one. Past 700 yards, im putting out more energy anyways. Before that, the numbers are still close. I guess ill just have to go build that 338 lapua and get my 6.5 creedmoor in an AR10 platform and call it good. Or maybe a 20mm as well but thats expensive.
