I recently came across an article on TheFirearmBlog about an ultimate caliber, discussing the push for an new intermediate cartridge for military use, found here: http://www.thefirearmblog.com/blog/2014/09/30/weekly-dtic-2/. The article also linked to the OP's personal blog, with a post from late last year: http://196800revolutionsperminute.blogspot.com/2013/11/the-case-against-general-purpose.html. I'd like to share my own opinions as well as see what the rest of you might be thinking as far as a new military cartridge goes. While I don't necessarily disagree with the author on many of his points, I felt that he was being a smidge too close-minded about some of the more recent developments in cartridge design as well as some of his complaints. Specifically, his dislike of the 6.8 SPC and 6.5 Grendel, in the role of a military caliber. The main issue I see with both of these calibers is that they were designed as a retro-fit conversion to an existing system, the AR-15 platform. Simply put, if Bill Alexander or Remington hadn't concerned themselves with fitting these rounds into an AR-15's action, holding to the overall PSI of 55,000, or in a stanag magazine dimension, they would be very different in O.A.C.L. as well as case capacity. Looking specifically at the Grendel, with an overall max length of 2.260" the case only holds 30-34 grains of water. Simply increasing the overall length to 3" would allow for a decent increase of capacity, but would negate any chance of utilizing the caliber without a tailored rifle design. The only downfall is that if the military decided on a brand new caliber, they would also need a new rifle design. I agree with the author on his rejection of an ultimate, single caliber for every job, but do believe that there're superior alternatives to our current military cartridges. I also do see the utility of the 6.5 grendel, specifically in a military setting. However, it would require considerably more training on the part of the armed forces to use those benefits, and there would be considerable diminishing returns for this kind of ranged training. I still think this cartridge does hold value for the military, simply because the range would be there, if necessary, without much in the way of downsides. He also comments on the fact that current factory offerings are anemic in velocity and performance, the grendel's SAAMI spec 30 degree complex throat, the lack of ability to utilize tracers or non lead based projectiles as well as being a straight walled cartridge. To all of these, I think he is making mountains out of mole hills. If the Grendel ever reaches mainstream acceptance, factory loads would become exponentially better, also allowing for tailor made powders and projectile combinations, simply through supply and demand. Both Barnes and Nosler make 6.5mm lead free offerings, both of which are quite effective in both expansion and penetration, though our military forces will probably never use expanding ammunition in general practice. And while a tapered case allows for more reliable extraction, the 5.56 NATO is a straight walled case, I don't see the relevance here. As for the complex throat, decide which grain weight of projectile(s) you want to use, and make a new throat to accommodate only those. What do you guys think? Is there a caliber or cartridge to rule them all? Are my points valid or are the blog postings correct, there really is nothing better out there than the 5.56 and 7.62x51?