The only problem there is why did they need a 140 grain 7mm bullet for that? A US study in 1930 showed that a .20 cal high velocity round was the best choice for within 500 yards:
They screwed up by trying to make their new cartridge a universal cartridge and compromised their basic premise and in fact ensured the death of their project by US demands. They should have pushed for a two caliber standard, one for their 400 yard max range (what they actually wanted, not what they scaled up to to appease US demands), and one for their MMG/HMG/long range rifles. Of course they could have just used the .25-3000 as the conceptual basis for a cartridge, as they could neck down the 7.62 case to 6.35mm and standardize on one case to cut cost, but still have all the benefits of a light, fast bullet that would dominate out to 500 yards. While certainly not as good as the 5.56 in that role, it still would be much better than the .270 or .280. Conversely they could have also have done what the US ended up doing with their 7.62 NATO cartridge in Vietnam: make a very light bullet for it and use the same case:
What if in order to deal with the problem of automatic fire controllability the M14 was adopted with the US low recoil 7.62 cartridge? Apparently it was fully comparable in effectiveness to a regular 7.62 NATO cartridge out to 500m, had 37% less recoil, and made the weapon controllable in full...
www.alternatehistory.com
The US demands made more sense in the context of a universal cartridge for all roles, but that universal cartridge concept was bunk and proven so in combat relatively quickly.