My take is that the Grendel may be a bit more popular these days and the 6.8 SPC fading. Howa and Ruger have both released new rifles (bolt actions) in the Grendel , not sure what is going on with the 6.8. Casual browsing at the stores seems to indicate that Gendel ammo is now more common (than 6.8) over the counter as well, but I could be wrong about that
This is sort of like saying Tesla is more popular these days and Toyota is fading.
As a Grendel shooter (I have 4 with a 5th on the way) and NOT a reloader, please tell me in what part of the world Grendel ammo is more common than 6.8 spc. There are only a few commercial offerings. There are 2 from Hornady, 3 from Federal of which one is gone until April, Nosler has 1 target load out ($2.17 per round) with 2 more loads to be offered. PPU supposedly will get around to shipping around the end of the year to the US, probably just ball ammo. Wolf has very limited distribution. Alexander Arms has their specialty ammo at $1.50 per round (5 loads). Of these, I have never seen more than 2 offered at the LGSs, Academy Sports, and our local Cabelas carries ZERO Grendel ammo. Then there are a couple boutique offerings with really high priced ammo such as from Precision Firearms (several offerings, well made, not timely, ~$2 per round).
Grendel popularity is growing, but it is a slow growth, which is part of the reason why (ammo) manufacturers have been slow to embrace it. 6.8 spc is still more popular.
Comparing ammo from ammoseek.com, Grendel has all of 217 listings right now from just a few manufacturers...
https://ammoseek.com/ammo/6.5mm-grendel
6.8 spc has many hundreds from a whole bunch of manufacturers.
https://ammoseek.com/ammo/6.8mm-remington?ca=brass
The 6.5G is sort of the quirky, delusional cousin of the 6.8. I have two (18" & 20") that are neither as accurate or functional as the ARP 6.8.
This isn't a caliber issue. That is a gun/barrel/ammo issue.
Unlike the Grendel or the Blk Out, the caliber doesn't have a manufacturer pushing the caliber for sales.
Every company that makes 6.8 spc is pushing the caliber for sales. It is how the business works.
I also read where another country plans to adopt the 6.8 caliber for its military. The caliber is definitely not fading.
When you talk about "the caliber" of 6.8 and the discussion here is of 6.8 spc, which country has already adopted it and which country is planning on adopting it? The US isn't adopting 6.8 SPC and I don't see where any other countries have either.
Looking at Wiki's page on military calibers, I don't see a single 6.8 listing. There are 6 for 6.5, but none are Grendel.
https://en.wikipedia.org/wiki/Category:Military_cartridges