7mm or .308?

[nralifer]

lancetkenyon,

I assume your last post describes the test on the rifle you built in memory of your father-in-law. That was a very touching gesture matched only by the quality and beauty of the rifle. Thanks for sharing. Looks like you have an ideal test facility. A calm day in SD is 10-15 and gusty. I should spend my time making wind turbines instead of bullet testing.

 

For the sake of illustration the 150 BD bullet in my the post that compared it to the Hornady 7mag factory loads, plugging in your atmospheric conditions into the shooters trajectory calculator gives the following result for 500 and 1000yd drop and sight height 1.5"

 

MV 3150 150gr all copper HP tipped BC .480 (measured) 500yd = 33.4" &1000 yd = 242"

 

Clearly the 7mm 180 gr Berger is a superb bullet. We have used Berger as a benchmark to test the efficiency of our bullet designs. By reducing barrel friction and using a more efficient powder the performance of the 308Win is clearly increased. This bullet is stable out of a 1:10 barrel. Eventually we will see what can be done to the 180gr 30 cal bullet to function from a 1:8 twist.

 

Above are some examples of the bullets we have been making and testing. The 30 cal 150BD in question is just to the left of the 155 Amax (red tip far Rt). The 150BD has 20-25% less bearing surface than the Amax. The big one to the far Lt is a 260 gr 338 bullet and the one in between is a 180gr 30 cal solid.

[trphyhntr]

isnt the down range velocity and lbs of energy far greater with a 7mm?

[AverageJoe]

isnt the down range velocity and lbs of energy far greater with a 7mm?

No. A .308 caliber bullet will retain more energy down range than a .284 caliber bullet. Compare a 210 vld in .308 vs a 180 gn vld both fired at 2900 fps and see what you come up with.

 

Now if you are trying to compare a .308 win vs 7mm rem mag then yes the 7mag will win. Seems this thread started out comparing .308 vs .284 and turned into .308 win vs 7mm mag.

[trphyhntr]

 

isnt the down range velocity and lbs of energy far greater with a 7mm?

No. A .308 caliber bullet will retain more energy down range than a .284 caliber bullet. Compare a 210 vld in .308 vs a 180 gn vld both fired at 2900 fps and see what you come up with.

 

Now if you are trying to compare a .308 win vs 7mm rem mag then yes the 7mag will win. Seems this thread started out comparing .308 vs .284 and turned into .308 win vs 7mm mag.

 

oh i didnt even know what i was reading i guess lol.

[80Deuce]

Easy 7mm08

[nralifer]

lancetkenyon,

You offer is very generous. We have the 150,180 and 196 gr 308. From the looks of it you likely have a 30 cal magnum of some type, which would be perfect. My email is shrlandgeo@gmail.com. Shoot me an email with contact information and we can arrange to send you some.