My undersanding is that tradeoffs must be made between range, accuracy, weight and barrel life.
e) Denel, the South African gun maker, that had emerged as the single vendor for the tracked version, was blacklisted in 2005 on another deal involving anti-materiel guns.
Especially with those anti-matter shells! They probably create mini-black holes with each impact!
The EFC (equivalent full charge) life is shorter on some of the “tighter” barrels. Some of these countries don’t practice like the US, so barrel life isn’t the concern that it is in the US and other countries.
That's true enough, but the sad fact is that the US Army's gun artillery is not the best there is. Hasn't been for a very long time - even when I was on active duty as an artillery officer in the 1970s, that much was clear. Sure, our logistics, fire control, radar, etc. are excellent, but in a gun duel, I wouldn't want to have the US tubes at longer ranges.