02-27-2014, 07:09 PM
cory Wrote:...If an ammo manufacturer were to offer rounds in that pressure (58ksi), and a box of that ammo was put into the original AR15 design by mistake the weapon would be fine assuming the weapon was built properly. It would take a significant amount of bad decisions to see the problems you mention. What would likely happen is we'd see +P Grendel ammo.Well, one good result of having a bunch of +P (58ksi) ammo around is that owners of short-throated Grendels would have had instant feed back that something was wrong with their rifle as a result of the cratered primers, streaks on the case head, generally abused brass, and lots of broken bolts. I guess that is really a bad thing!
More choices for the Grendel horde, how is this a bad thing?
I recall that there were a lot of broken bolts earlier in the history of the Grendel, and one of our members dug through the posts and determined that the vast majority of these incidents came from handloaders. Speaking from personal experience early in my reloading career, I was also one who wanted the most MV -- call it a misguided manhood thing. One of the probable contributors to broken bolts is that many of these guys were loading to levels where they routinely got classic high pressure indicators and then picked a go to load somewhere at that level, which is well above the 52,000 psi SAAMI ceiling. Bolt fatigue sets in a lot faster when higher stresses are put on it.
Back to the velocity thing, one of the reasons (other than marketing by Big Green) folks took a shine to the 6.8 SPC is that Remington and others did not hesitate to implement lightweight bullets in the .277" diameter. That boosted velocities. It also gave this latter-day recoil-averse shooter softer load options for his .270!
So, a path to velocity is to go lighter. One of the long-standing benefits of the 6.5 bore is the proliferation of heavy-for caliber bullets. This means that the Grendel can take advantage of these good BCs and turn in excellent long range performance. Most hunters rarely take shots out as far as 300 yards, let alone 500+ yards, meaning that the Grendel would be OK with shorter range bullets for most deer and hog shooting. There is, however, some hesitation over going much lighter than standard hunting weights because experiences with the .243 Winchester and 6mm Remington showed us that a 90 grain cup and core bullet presses the light side of what one should consider for hunting the heavier deer.
This takes us to one of the few places where I will grit my teeth and advocate a bullet technology soon to be mandatory where I live. A 75 to 90 gr lead-free expanding bullet is arguably good for all North American deer. The 75 gr lead-free bullet gives a wound channel area that is about the same as a 115 grain classic bullet like the Core-Lokt while the 90 gr lead-free is more the equivalent of a 135 grain classic hunting bullet. Going to these bullets would then allow one to get interesting velocities while assuring decent deer-anchoring terminal ballistics.
A few of us would need to shoot a bunch of these bullets, collect records of harvested animals, and publish results in places where casual hunters start asking where to get this stuff. The challenge is where to get these lightweight custom bullets for load development, ballistics tests, and field results.