CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information.
I thought it's be fun to run some numbers in QuickLoad to get a theoretical comparison at SAAMI spec numbers and equal barrel lengths.
24" barrel, SAAMI max pressure, uncompressed loads:
280Rem
110gr Barnes TTXS, 3,405fps
139gr Hornady SP, 3,085fps
180gr Berger BTHP, 2,722
708
110gr Barnes, 3,246fps
139gr Hornady, 2,972fps
180gr Berger, 2,595fps
So, it looks like the 708 runs right around 125fps behind the .280Rem at almost all bullets weights. Both cartridges will push at least a couple of those bullets slightly faster with compressed loads but neither gains enough to change the numbers to any real degree.
The 708 gets the bullets to speeds with a whole lot less powder though.
Both max out the 110gr with RL17, the 708 using only 49.1gr, the .280 using 57.8gr. The 280 is 4% faster but uses 22% more powder. The 280 is 25.4% efficient, the 708 is 27.9%
With the 139s, the 708 does it with 46.9gr RL17 (an excellent 30.5% efficient) while the .280 needs Ramshot Hunter and is 26.7% efficient.
With the 180s, the 708 likes W760 and is an very excellent 33.7% efficient, the .280 is likes RL19 as is an excellent 29.1% efficient.
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The problem, as you so eloquently put it, is choice.
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Last edited by Brian Pfleuger; November 18, 2012 at 12:52 PM.
