.30 cal vs. 7mm

Your 2 links take you to the same page.

I took the liberty of punching a few numbers off the Hodgdon/win/IMR reloading data site.

7mmMag

160gr partition
61.8 grains Sup780
2829 velocity

25ft/lbs recoil energy

300WM

180 grain e-tip
70.0grains SUP780
2840 velocity

32ft/lbs recoil energy

Or about a 28% increase.
 
kman300 said:
Not sure what bullets you are using but a 7mm rm with 162amax/168bergers at 2950fps or the 180 berger at 2850 will be pretty much the same fps and ~150ft/lbs less than the 300 wsm with a 208amax/210berger at 2850.

160gr accubond at 3k and a 200 accubond at 2850fps again has the same fps at 1000 but the 200 accubond has ~200ft/lbs more energy.

Again, not sure what bullets you are using but the 300 short is no slouch.
Click to expand...

There is no way i could get a 210 berger going 2850fps out of my 300 WSM , being 2850 is all i can get with a 165gr acubond. I can only get my 180 berger out of my 7rem going 2750 ... you do the math. I tip my hat to the man that can get accuracy out og a 300 WSM with a 210 going 2850.

Not only that i would have to imagine you would have to go to a tighter twist with a custom barrel to even stablalize a 210gr.
 
pilot2001 said:
There is no way i could get a 210 berger going 2850fps out of my 300 WSM , being 2850 is all i can get with a 165gr acubond. I can only get my 180 berger out of my 7rem going 2750 ... you do the math. I tip my hat to the man that can get accuracy out og a 300 WSM with a 210 going 2850.

Not only that i would have to imagine you would have to go to a tighter twist with a custom barrel to even stablalize a 210gr.
Click to expand...

You are doing something very, very wrong if you are only getting 2850fps with a 165gr nab out of a 300 wsm.

Load data straight from Berger has 4 different powders that give you 2800+ with the 210 vld.

I get 2840fps with imr 7828 out of a bone stock m70 extreme weather. Comes with a 10 twist. Not sure what gun you have but you only need 11 twist for the 210.
 
I agree, something isnt right, 2850 is under starting charge velocities for the 300 WSM with a 165 AB. A 200 gn AB should hit 2850 in most rifles chambered in 300 WSM!
 
joe-nwt said:
Your 2 links take you to the same page.

I took the liberty of punching a few numbers off the Hodgdon/win/IMR reloading data site.

7mmMag

160gr partition
61.8 grains Sup780
2829 velocity

25ft/lbs recoil energy

300WM

180 grain e-tip
70.0grains SUP780
2840 velocity

32ft/lbs recoil energy

Or about a 28% increase.
Click to expand...

Those are some pretty mild loads.
 
And I screwed it up royally anyway! LOL!

Here how it SHOULD read:


7mmMag

160gr partition
65.7grains Sup780
2948 velocity

27.6ft/lbs recoil energy

300WM

180 grain sft scir
70.0grains SUP780
2923 velocity

33.1ft/lbs recoil energy

Or about a 20% increase.

Sorry.:redface:
 
kman300 said:
You are doing something very, very wrong if you are only getting 2850fps with a 165gr nab out of a 300 wsm.

Load data straight from Berger has 4 different powders that give you 2800+ with the 210 vld.

I get 2840fps with imr 7828 out of a bone stock m70 extreme weather. Comes with a 10 twist. Not sure what gun you have but you only need 11 twist for the 210.
Click to expand...

Then again, you can get 3050-3100fps from a 162AM from the 7RM/7WSM, and 3000fps with the 180VLD...
 
Jordan Smith said:
Then again, you can get 3050-3100fps from a 162AM from the 7RM/7WSM, and 3000fps with the 180VLD...
Click to expand...

In reloading many things are possible. 2775fps with a 230 berger for example. The examples I posted are what "normal" data says (berger data). Once you start citing data that people worked up on their own any common ground of comparing two cartridges goes out the window.
 
Sectional density depends on bullet weigh and style, not caliber. The 160 gr 7mm bullet is comparable to a 180 gr 30 caliber for all practical purposes and the slight edge in ballistic coefficient is given up on the other side of the equation when we figure in the loss of velocity due to the smaller bore. More simply put - a 30 caliber 150 gr bullet can be driven faster than a 150 gr 7mm bullet because the 7mm will top out in pressure at a lower powder charge than the 30 caliber. A 7mm mag shooting 160 gr bullets is nearly the same ballistically as a 30-06 shooting 165 gr. bullets but it uses 20% more powder to get the same results. So much for the superiority of sectional density.
 
Cleftwynd said:
I thought sectional density was the diameter of the bullet and the weight? "Sectional"?? and "Density"??
Click to expand...

Yup, pretty much everything that jethunting posted is out in left field, except for the part about being able to drive a 150gr .308" bullet to a faster MV than a 150gr 7mm bullet, using an equal powder charge, but it has nothing to do with topping out at a lower powder charge, and everything to do with the base of the bullet having a larger surface area for the pressure column to push on. Everything else mentioned is erroneous.
 
Jordan Smith said:
Nosler shows R22 hitting 2970fps with a 175gr NP, which has a larger bearing surface than the 180VLD.
Click to expand...

Ah yes. Let's tell people reading this thread to inform themselves that if we take 175gr NP load data from nosler and apply it to the 180vld from berger we can call it published load data for 3000fps for the berger. And of course we will disregard the actual load data from Berger, for the 180 berger because we can just take the 175 nosler data and use that.

Hodgdon shows 2735fps with a 220gr rn for the 300 wsm. Published data for the 230gr at 2775fps then?
 
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