6.5 Grendel versus 6mm ARC for whitetail

[Stinky Coyote]

It took awhile, but I finally ran the .243 through the age old formules and here is the same chart with the results: (Note the correction on the 6mm ARC, it was misplotted.)

Outside of the range of 200 yards to 210 yards, where it is either going too fast (meat destruction) or lacks penetrating power (>1300 ft/sec for elk), the .243 is a P.O.S. cartridge and caliber. This is nothing new. I was told that as an adolescent in the 1960's. This chart is just a metaphor for what has been known all along, the 6mm (.243) is not a caliber to be hunting big game with. What was Hornaday thinking when they brought the 6mm ARC out as the panacea for all hunting needs? What are our sporting good suppliers thinking when they dropped the Grendel for the ARC?

If this mindless, erroneous propaganda continues, and it well, the 6.5 Grendel will soon be dead. This winter we have travelled 5,000+ miles, visited 5 gun shows and 20+ gun stores. During that time I bought every grendel that I encountered, a total of three, and one of these was from Gun Brokers. This is commercial warfare, and your forum is the front lines.[ATTACH=CONFIG]19475[/ATTACH]

grendel will survive, so will the arc, these are proper 21st century cartridges, they are just getting warmed up, like the 6.5 creedmoor over the 6....the 6.5 will always get the nod for hunting and the 6 will always get the nod for steel work, funny the 6.5 came first in this so it was a slower start, the arc will help pull it along as there's far more steel/competitive 6mm guys that love the short fats than hunters so the arc (I mean 6mm Grendel ) is a good thing, also, terminal ballistics still largely misunderstood, the best formula to go by at this point is starting sd, construction type, and impact velocity....FOR GAME INTENDED

the best example of why ft/lbs is useless is bell and his 6.5 mannlicher (on elephants) vs the 700 nitro express, the 6.5 mannlicher has higher sd solids launched at higher velocities (I think 156-160 gr, .32 sd at ~2350 fps) and the 700 nitro throwing 1000 gr, .29 sd, at 2000 fps....you've got less than 2000 ft/lbs with one and about 9000 ft/lbs with the other but the mannlicher is more reliable into the brain pan through a foot of elephant skull, and the 700 nitro has been knocking elephants out and they come to and rodeo begins....the sd doesn't change on these solids but it clearly shows that .29 sd at only 2000 fps is not enough penetration regardless the energy behind it, but bell learned long ago that .32 sd launched over 2300 fps is enough

now you look at our game and bullets, we use rapidly changing sd bullets, we currently don't measure the rates of this change to compare, I'm sure we will at some point in this century, but the point is then that we have to visualize that we must start with an adequate amount of sd for game intended and a construction type and velocity range to make the bullet work for game intended, ie; you can have a good starting sd but if construction is too fragile for the velocity range you will have violent damage over too short a distance in the animal (taking only a shoulder perhaps) but the same bullet slowed down can then do the work required over a longer distance....so the Weatherby barnes is an example of one end of spectrum, with bullets retaining what sad sd they start with but driven at wicked speed to make them work better, inefficient especially at the shooters shoulder, but you can take a rapid construction (heavy for cal) type bullet at moderate velocities and have very efficient performance, enter the 6.5's as they have unusually high sd for caliber bullets across the range, so you can do more with a lot less powder burned

anyway, energy is a useless number, I figure it will be used properly at some point once we have sdrr (sectional density reduction rate - a term I coined in 2020) and err (energy reduction rate - also coined in 2020) and it will work like this, we can measure a finished bullets sd over a distance in gel perhaps, then use the impact energy and divide it over the inches travelled to give the err, which would then help explain to folks the likely damage they may see internally over that distance as compared to another cartridge/bullet example, you may have a creedmoor dumping 70 ft/lbs per inch over 22" and a 300 wm dumping 130 ft/lbs per inch over 26"....just random examples, back to the sdrr...it would be a measure of penetration depth it will achieve, so you'd have both measures (penetration and energy) in more objective format!, I feel like this will be coming this century, it must, because the amount of cyberspace eaten up discussing the still subjective subject is proof we have a long ways to go, inflight ballistics we've got down pat to 21st century levels of understanding...not much work left to do there, but terminal ballistics we're still stuck in the 20th century

and a 6 arc with 108's will shine from 200-600 yards no prob, it's got great sd, but agree it's a bit fast on the front end for that bullet so will want to keep it in the ribs on bigger animals, the grendel speeds from muzzle to 4-500 yards is absolutely perfect for 123gr eld/sst bullets construction type, maximum efficient imo, keeping impacts between 2350-1750 fps, no elk/moose will take the 123 well in the ribs at 400 yards, you will get your 20" penetration and necessary damage through that travel, the barnes are too tough for these cartridges imo, really limit their range as they need at least 2000 fps to open up just a tiny bit, you will kill with the barnes but I believe more poked holes and longer follow ups whereas you'll walk right up to your game a lot more frequently with the eld/sst bullets