Interesting experiment-terminal performance test

[Mobuck]

In preparation for our elk hunt, Grandson took a turn behind the 7mm08. Not a bad experience although I did force him to use my "Kick-Eze" recoil pad. He handled it well enough at the bench and put both shots attempted from a sitting position using shooting sticks on the 12" plate @300 meters. In order to get an idea of the performance of the 7mm08 Barnes 120 grain TXS tipped, we shot water filled chemical jugs(triple rinsed) at 225 yards and compared results with a 280 Rem using a similar bullet in 140 grains.
7mm08 achieved 24" of penetration with a very uniform expansion and very violent expansion in the first 12"-pretty much what I expected. Quite similar to the performance of my 25/06.
280 Rem was a surprise as it penetrated 32" with violent expansion in the initial 12-16". Unfortunately, we lost that bullet because the force of the impact was sufficient to move the line of jugs enough to overturn #5 before the bullet penetrated it. We're talking about 5x 2.5 gallons of water (approximately 100#) which was sitting on bare dirt.
Moral of the story-yes, the 7mm08 is adequate for our needs BUT bigger is better and the 280 is in a different category of performance.

 

[JCK]

Apples to oranges!
Without chronographing the ammunition and using different bullets, though similar means little.
I've got both a Remington M7 in 7mm08 and a M700 in 7mmRemMag.

Using the SAME bullet, the difference is about 100yds in terminal performance. The M7 will push a 150gr conventional bullet 2,800fps (RL17, 20"bbl.). The 7mag, about 3150fps ((RL22,26"bbl.)
With a monolithic bullet, the 7mag would perform a good deal better as the longer barrel and slower burning powder would be more forgiving. The smaller case will be a handicap. Perhaps 2,600fps vs 3,000fps.

The monolithic bullets cause greater pressure due to higher engraving forces.
The .280 just affirmed this! In a 26"bbl, the .280 is a near equal to a 7mag with a 24"bbl.
I always wanted a .280AI. but a factory complete 7mag was cheaper than just a .280/.280AI barrel.
Likewise, I was going to rechamber the 7-08 to .284win but made the "mistake" of chronographing some PMC 139gr factory ammo. It was running 3,000fps my goal for a .284, so why bother with the expense and maybe mess up a GOOD barrel!

 

[Mobuck]

"Apples to oranges!
Without chronographing the ammunition and using different bullets, though similar means little."
Maybe?
What it did provide was a comparison between an available factory load in a lighter recoiling cartridge versus a known performance load in a cartridge which we deemed presented more recoil than the shooter could handle. We compared a bullet with known capability to a bullet of unknown performance at a distance which one would reasonably expect to make a hunting shot. Already more realistic than a u-toob video of "Jimbo & Larry" shooting at modeling clay @ 50' cause they can't hit the target any further away (which proves absolutely NOTHING).
Chronographing (which I could do) wouldn't add significantly to our knowledge since the FL is what it is and not a factor we can adjust/change. Similar but not identical bullets is also a factor which is not easily subject to change since finding 7mm08 ammo in a controlled expansion variation is questionable.
In addition, firing the known performance bullet into identical 'test media' (a stretch of the term but no less true) gave us a 'calibration' of the 'test media' making the results more informative.