7mm vs 30cal for mile at 1000' Density Altitude

[Hawk45]

Getting ready for my first ELR build. I have all my specs except for caliber. My initial intention was a 300WM, then thought about the 7WSM, now I'm back to the 300WM. My concern with the 7WSM is being that most of my shooting is at 1000' Density Altitude I've read that the 180s can destabilize when transitioning the sound barrier as they go transonic at around 1600yds. I've read the 30cal 208 Amax transitions just fine. I still need to look into if the 7mm 162 Amax will stay stable. But based on the above, should I stick with the 300WM or chance it with the 7WSM? To add, most shooting will be inside 1K, but I want a rifle that while still enjoyable to shoot a 1K but have the stones to get out farther than the .308.

Also, would it be optimal to go with a long action for the 7WSM to maximize seating longer VLD bullets? I don't mind the longer throw as I won't be shooting for speed.

Thanks guys.

 

[bohem]

Re: 7mm vs 30cal for mile at 1000' Density Altitude

The 162 Amax with the new "AMP" jackets has been rumored to transition; I'm going to try it tomorrow at 1200-2000yd and see if I can confirm that it works.

The 180 Berger and Berger Hybrids did not work for me out there at 2000' DA.

I have successfully shot the 208 Amax well in excess of transition at 0' DA from my 30-06.

Either one will treat you REALLY well, there are pros/cons to each but considering the amount of powder, relative bullet cost, brass cost, etc. the biggest "standout" to me is the barrel life difference.

If you're worried about transition behavior I'd take the 300WM.

 

[Hawk45]

Re: 7mm vs 30cal for mile at 1000' Density Altitude

Thanks bohem. To the point of barrel life, I'm guessing the 300 will have a longer life, would that be the correct assumption, all things equal (rate of fire, velocity, etc).

 

[SVG308]

Re: 7mm vs 30cal for mile at 1000' Density Altitude

Don't forget about the new 30 cal Berger bullets as well. The 300 with 208 AMAX makes for a very economical and well performing ELR rig.

 

[Bigwheels]

Re: 7mm vs 30cal for mile at 1000' Density Altitude

I made the switch from the 208 A Max to the new Hornady 225 HPBT. I have had both out to 2000 yd, & hands down the 225's outperform them beyond 1000 yd. Pushing them to 2800+ fps I can reach 2000 yd in 85-90 moa depending on atmos from a 100 yd zero.
300Wm 28" Kreiger 1 in 10 tw.

 

[Wheres-Waldo]

Re: 7mm vs 30cal for mile at 1000' Density Altitude

What about a 7WSM with Bergers' 180 Gr. Match Hybrids?

.674/.345 G1/G7 BC + 3000 FPS goes transonic AT 1760 yds @ sea level....

 

[Jeffvn]

Re: 7mm vs 30cal for mile at 1000' Density Altitude

Since I live in Las Vegas, and shoot locally I can't speak to a DA of 1000, as I have never seen anything that low since moving here 5 years ago.

I can speak definitively to the Berger 180 vlds here in the desert at 2,100 alt and DAs above 3000. They were and are stable to 1,800 yards from my brother's 284 Winchester at 2,850 fps from his 1:9 twist, and have always been stable from my 7WSM with a velocity of 2,940 fps 1:9 twist.

I can't speak to the Hornady 162, as my 7WSM hates them, and my brother never tried them.

JeffVN