Forget factory ammo, compare handload data with similar pressure data and powders, both with 24� barrels:
OK, I will.
From Hodgdons powders:.280 Rem
140 GR. NOS PART H4831 58.5 2927 48,500 CUP
7mm Rem:
140 GR. NOS PART H4831 64.0 2950 50,200 CUP
Note: more powder, more CUP's 23 more FPS
.280
162 GR. HDY A-MAX H4350 49.5 2614 49,900 CUP
7mm:
162 GR. HDY SPBT H4350 58.0 2799 49,400 CUP
8.5 gr. of powder more than .280 and 185 fps more velocity.
Using an A-MAX bullet, that extra 185fps adds 135 yards to the energy, momentum and velocity levels of the .280 Rem. Not a bad trade off for 8.5g powder in my book. My 7mm RM is an elk gun first and everything else second. 160g bullets were my choice for 25 years.
I put two different sized bullets and powders so people can see for themselves:
Like I said the .280 shoots the smaller stuff better,(not better than a 7mm) than the heavier stuff.
The 7mm shoots the heavier stuff better than the lighter stuff.Even better than the .280 but at a cost. More powder, magnum barrel blast.
If a guy was dead set on the heavier bullet weights, then head on over to the 7MM Rem.
Greater case capacity wins every time it is tried. That�s why the .280 Rem cannot keep up with the 7mm RM.
Not true on the lighter weight bullets. 7mm tends to waste powder there.
4100fps �
Also from Hodgdon�s load data:
.280 Rem = 100g Sierra HP, 63.0g H4831 (max load, compressed), 3266fps, 46,000 CUP
7mm RM = 100g Sierra HP, 71.0g H4831 (starting load), 3316fps, 43,300 CUP
Hmmm, can�t get any lighter, the .280 is maxed out due to case capacity while the 7mm RM is just getting started, runs faster and has about 6% less pressure...
.280 Rem = 100g Sierra HP, 60.5g H4350 (max listed load), 3379fps, 49,200 CUP
7mm RM = 100g Sierra HP, 65.0g H4350 (starting load), 3334fps, 44,800 CUP
OK, the 7mm is marginally slower in this example, but again the .280 is at the max listed load while the 7mm RM is again just getting started and is at 9% lower pressures. Of course, that�s what larger cases do for you and the 7mm RM has significantly larger case volume � about 19% greater (67.5g water for the .280, 80.8g for the 7mm RM per AmmoGuide.com).
The 7mm RM�s larger case volume also means the powders that are ideal in the .280 Rem are not necessarily ideal in the 7mm RM and vice versa. While there is some overlap, the 7mm RM shines with slower powders, for which direct .280 Rem/7mm RM comparisons are difficult to come by, particularly if actual pressure data is required (which is why I used the same powders for my comparisons). One can compare the maximum velocities achieved with each cartridge, however, knowing that they data providers kept pressures at or below SAAMI�s maximums.
SAAMI pressure for the .280 Rem is 60,000 PSI while the 7mm RM is just slightly higher at 61,000 PSI. For comparison purposes the .280 Rem AI is, I believe, 64,000 or 65,000 PSI. In any case, the .280 Rem AI version has more case capacity than its parent .280 Rem case and the .280 Rem AI still can�t keep up with the 7mm RM.
[Note: For a more fair comparison to the .280 Rem AI you need to push the 7mm RM to the higher .280 Rem AI pressures. Since the primary difference between the 7mm RM and the 7mm WBY is pressure standards (case capacities are 80.0g water for the 7mm RM, 81.3g for the WBY per AmmoGuide, a miniscule 0.6% difference), and since the .280 Rem AI and 7mm WBY pressure standards are similar (64-65,000 PSI for the .280 AI, 65,000PSI for the 7mm WBY), I�ve included the 7mm WBY in the Nosler data below.]
Nosler 6, fastest loads:
120g
3296fps = .280 Rem, 54.5g W760, 87%
3396fps = .280 Rem AI, 60.0g H414, 92%
3570fps = 7mm RM, 70.05g RL19, 93%
3653fps = 7mm WBY, 84.5g RL25, 108%
140g
3152fps = .280 Rem, 57.0g RL19, 99%
3266fps = .280 Rem AI, 63.0g AA3100, 105%
3340fps = 7mm RM, 67.5g RL22, 94%
3361fps = 7mm WBY, 79.0g H1000, 101%
150g
2995fps = .280 Rem, 55.0g RL19, 95%
3107fps = .280 Rem AI, 63.0g IMR7828, 103%
3248fps = 7mm RM, 63.0g IMR4350, 85%
3302fps = 7mm WBY, 77.5g RL25, 103%
160g
2929fps = .280 Rem, 61.5g MagPro, 103%
3045fps = .280 Rem AI, 59.5g VV N560, 102%
3077fps = 7mm RM, 72.0g MagPro, 92%
3197fps = 7mm WBY, 76.0g RL25, 102%
175g
2760fps = .280 Rem, 52.5g IMR4831, 91%
2828fps = .280 Rem AI, 58.5g IMR7828, 96%
2970fps = 7mm RM, 62.5g RL22, 88%
3061fps = 7mm WBY, 78.0g Retumbo, 103%
Say what you will, Nosler tends to have some of the fastest data available for the cartridges they list. Since Nosler standardized the .280 Rem AI with the introduction of factory ammo and rifles chambered for it, it is doubtful that they sandbagged the published velocities for it.
The simple truth is the .280 Rem can�t keep up with the .280 Rem AI which in turn lags the 7mm RM even though the 7mm RM runs at lower pressures. If you like, you can run through the same .280 Rem/7mm RM comparison exercise with Speer, Hornady, Barnes and other data sources and for each you will find the .280 Rem velocity lags the 7mm RM in all bullet weights.
Although I used 160g bullets in my 7mm RM for many years, these days I�m shooting 120g bullets at 3579fps and 140g bullets at 3358fps � velocities I wouldn�t begin to attempt in a .280 Rem, regardless of the powder.
I�m not knocking the .280 Rem - it�s an efficient cartridge and a very good one. Nevertheless, it cannot keep up with the 7mm RM in terms of velocity due to its smaller case volume.
