I have been a lurker for some time and I registered just to make this post
@jpattersonnh - You sir, are an ignorant @$$hole. You sit here and flame others simply because they have a differing opinion? You sit here and preach about how "superior" the 7 RM is to the .338 win mag, but you compare apples to oranges... Let us at least compare grapefruit and oranges...
Quote:
Originally Posted by jpattersonnh
The .338WM actually has less retained energy at 1000 yards then the 7mm when using 200gr bullets in the .338. MV is = to or 100fps less. At 500 yards the 7mm has 1525fpe w/ a 160gr, the .338WM has 1585fpe w/ a 200gr. The .338 looses after that. Makes you go Hmmmmm.........
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Energy is only part of the equation, the ability to maintain enough energy to penetrate is also important. I think most will agree that the "standard" which measures a bullets ability to penetrate is sectional density.
A 160 grain 7mm has a sectional density of .283 - a number many consider "adequate" for elk and other medium sized game.
A 200 grain .338 has a sectional density of .250 - a number many consider "marginal" for elk and other medium sized game.
To achieve a SD of .280 with a .338 caliber requires a bullet weighing 225 grains (SD = .281)
So, now let us compare 225 grain .338 WM to 160 grain 7mm RM using published load data. For this I go to Nosler because they happen to make my favorite bullet - the Accubond. I also like the Partition, but I just like the AB more.
To save a bit of time I am not going to post data under 500 yards, because the original thread asked about LONG RANGE
160gr AB over 60 grains IMR4350 (published max) in a 24" barrel = 2998 fps zeroed @ 200yds, 10mph cross wind:
At 500yds we are 37.3" low, windage is 16.2", we have 1635.6 ft/lbs of energy (considered by many to be acceptable for elk), our velocity is 2145 fps, and our time of flight was .591 seconds.
At 700yds we are 98.6" low, windage is 34.1", we have 1213.2 ft/lbs of energy (considered by many to be inadequate for elk), our velocity is 1848 fps, and our time of flight was .893 seconds.
At 1000 yds we are 272" low, windage is 78", we have 756.8 ft/lbs of energy (considered by many to be marginal for whitetail deer), our velocity is 1459 fps and our time of flight was 1.442 seconds.
Now lets move on to the .338 WM.
225 grain AB over 71 grains IMR4831 (published max) in a 24" barrel = 2807 fps zeroed @ 200yds, 10mph cross wind:
At 500yds we are 42.7" low, windage is 17.1", we have 2027.5 ft/lbs of energy (considered by many to be acceptable for elk), our velocity is 2014 fps, and our time of flight was .630 seconds.
At 700yds we are 72.6" low, windage is 25.5", we have 1509.5 ft/lbs of energy (considered by many to be acceptable to marginal for elk), our velocity is 1738 fps, and our time of flight was .951 seconds.
At 1000yds we are 309.2" low, windage is 82.1", we have 955.7 ft/lbs of energy (considered by many to be acceptable for whitetail deer), our velocity is 1383.2 fps, and our time of flight was 1.533 seconds.
Obviously the above numbers ASSUME that your rifle can safely handle, and accurately shoot the max loads... The results? Inside of 500 yds it makes no difference to any elk if you are holding a 7mm RM or a .338 WM AS LONG IT IS LOADED WITH THE PROPER AMMO AND THE SHOOTER CAN PUT 10/10 COLD BORE SHOTS INTO A 7" PAPER PLATE UNDER FIELD CONDITIONS AT THAT RANGE. Out to 700 yds the .338 gets the nod, beyond 700 yards both rounds fall well below Noslers 1800 fps recommendation for the Accubond to reliably expand making both load useless for any big game animal. The drop is irrelevant, because anyone serious about shooting long ranges does not estimate range or hold over. The windage difference between the 2 is minimal, you will make larger errors is estimating wind speed or with multiple winds at those ranges...
7 RM or .338 WM - It really doesn't matter. Pick one, then chose a bullet that is acceptable for your intended quarry. Work up a load that shoots well. Practice with that load under field conditions (improvised rests, multiple elevations, wind etc). While you are practicing you should be gathering data. This data will help you determine the maximum ethical range which you can engage.