Which just goes to show that the Goat Board, the Pig Board, the European ballistics tests... all have been proven right.
For the umpteenth time.
For some reason that I cannot fathom, the US military mind seems to gravitate to ideas that simply ignore vast amounts of ballistics research over the last 100 years.
The Garand was going to be chambered in .276 Pederson, but MacArthur vetoed the idea, mostly on supply logistics of the 30’s - we had a lot of .30-06 ammo on hand, and no .276 ammo. Simple decision.
When we got to the M-14, we had an opportunity to use superior ballistics, but the Army brass derided anything less than .30 cal bullets as being too small. Remember, it wasn’t that long ago for these guys that they were using .45-70’s in Trapdoor Springfields. So we got the 7.62x51 (.308).
The best exterior ballistics for a battle rifle are found in the .264 to .284 caliber range, depending on the length and configuration of the bullet, and in the 140 to 165 grain bullet weight.
The next “sweet spot” in exterior ballistics is about .338 to .340, in bullets of 300 grains or so. These recoil far too heavily at 2500 fps muzzle velocities, and they weigh too much for supply logistics.
An even more dramatic demonstration of how real thought and design in bullets can lead to outstanding exterior ballistics is the .408 Cheyenne Tactical, out of a private-sector Idaho company. The .408 CheyTac can outshoot a .50BMG for long-range sniper and light armor penetration - out to 2,000 meters and beyond. That’s the result of starting a weapon design with the bullet, and nothing but the bullet, and then once you’ve found the superior bullet, you work forward from there.
The 5.56 round was a ridiculous compromise all the way around, an example of what happens when someone starts a design with the action, then the weapon, then the chambering, then the bullet. It is only today, after 40 years of service, that the M262 round (a 77gr bullet) has appeared to provide some ballistic performance for the M-16.
If we want superior long range ballistics in an infantry weapon, we should start with a 6.5mm (.264) bullet, in 140 to 160grains, like the Lapua Scenar bullets. Then we should decide on how fast we want to push it, (like 2800 fps or so) and decide on a case. Then we should look at a rifle to push it.
Want to see long-range shooting in the private sector?
Look at the 6.5x284 rifles today. Superior ballistics at 1,000 yards and beyond.
Thanks for the treatise on the 6.5.
My 6.5X50R wildcat Contender salutes you.
I 2nd your observations. I think our brass have avoided the 6.5 because the Euro’s discovered it first.
I am a big fan of 6.5’s and am building a couple of converted Mausers in .260 Remington right now. One is for the wife and the other for me. I just turned/contoured/threaded/chambered her barrel. They are gonna be a matched pair, if I can find 2 stock blanks cut from next to each other.
With the addition of the 6.5 Grendel® to the product lineup at Alexander Arms, the history of no compromise design, engineering and innovation continues. The 6.5 Grendel® provides an extreme range capability for hunting, competition and tactical applications at ranges way beyond those previously achievable with this class of weapon. The 6.5 Grendel® has the flexibility to move from lightweight varmint bullets in the 90 grain class, which offer superb accuracy for competition and small game shooting, to mid weight 108/120 grain competition bullets and then on to 130 and 140 grain bullets, ideal for longer range, tactical shooting.
The 6.5 Grendel® is challenging the status quo in Military and Law Enforcement units around the world. First unveiled in May 2003 at the Blackwater Training facility in NC, the 6.5 Grendel® out-shot the 7.62 NATO at range with half the recoil. Still supersonic at 1200 yards, the 6.5 Grendel® delivered superior external ballistics to the 7.62 NATO. Utter reliability, superior external and terminal ballistics than the current state of the art, outstanding accuracy in a lightweight M16/AR-15 platform it is what appears to be the pinnacle for what may be achieved in the M16/AR-15 chassis. The 6.5 Grendel® is not a series of compromises, but rather the perfect marriage of mechanical function, internal, external and terminal ballistics all working in harmony.
Shooting a 123-grain Lapua Scenar with a ballistic coefficient of .547 and a muzzle velocity of 2600 fps delivers outstanding accuracy out to 1200 yards. At 600 yards, tennis ball size targets are no match for this flat shooting round. For extreme accuracy, formidable terminal ballistics and long range applications, the 6.5 Grendel® from Alexander Arms is unbeatable.
Compared to the 5.56 the 6.5 Grendel® with roughly twice the lead mass gives you the potential for twice the mass of fragments, and if maximum fragmentation is coincident with maximum temporary cavity, the terminal ballistics are quite convincing indeed all in a package that shoots flatter, with 50% less felt recoil than 7.62 NATO M80 ball.
Again, Alexander Arms is ahead of the curve. Currently in testing with the US Military for widespread adoption, the 6.5 Grendel® seems assured a place in history.
Very interesting post. Pardon my ignorance ... but what is your definition for “exterior ballistics,” and what constitutes a “sweet spot?”
M262 being hard to get, and M4gery being what many have, does anyone know a good recipie for reloading to M262 specs?