As an aside I generally assign type of cartridge by TL, so they change, with no alteration in price/availability, like so:
TL 5-8 brass casing
TL 8-10 caseless
TL 11-13 caseless OR binary
TL 13+ = gauss always.
This does nothing in a weapon's performance vs. armor either, it's just my way of acknowledging TL change.
I thought about that, but decided that a colonist with a TL 5 lever rifle wouldn't be comfortable trying to use TL 9 caseless rounds, even if it ought to work (not likely, IMO), and that that TL 9 version would have more muzzle energy, which might be unsafe for his rifle. So I assumed that the Imp standard version is the TL5 brass case version, available throughout the Imperium - at least in Starport extrality zones, if nowhere else. That meant the caseless or binary (or plastic Dardick trounds, if you remember them!) versions would be local manufacture.
So PCs revolving around a handful of worlds near each other might look for a TL 9 caseless 9mm Magnum, because they like the higher damage, but wide-ranging Travellers who rarely step foot on the same world in a year would buy the more widely available .357 magnum brass rounds to use in the same gun.
I went by the principle of lowest common denominator of user for the product. Caseless and binary would be driven by military and law enforcement needs in more sophisticated societies, and by the time those are as perfected as brass cartridges, gyrojet/accelerator weapons, snub guns, and gauss weapons will be overtaking the technology (I call the first 2 TLs gyrojet or rocket, and switch to accelerator for the more proven later TL versions).
I also really liked the 2300 AD FTE-10 - a honkin' huge gauss rifle, firing a big, relatively slow (in comparison to 4mm needles) round. The stock gauss rifle is based on the assault rifle concept. Civilian needs would mean semi-auto versions and varied calibers, not just high-cap, high-speed sliverguns. Gauss shotguns, big game hunting rifles/sniper rifles, and other LE applications, such as anti-civilian vehicle guns would proliferate within short order.
On a different note, I think the Imperium would mostly not be very concerned about modern assault rifles - too old and settled a tech. Weapon control advocates in the Imperium would look on those as the sort of thing to get around to banning some time after the sexier, more modern and potentially dangerous lasers and gauss weapons. The average citizen might intellectually realize they're all deadly, but who really thinks about muskets and arquebusses as threats today? Similarly, I think the real world, modern fetish for assault rifles, battle rifles, smgs, and similar auto-capable weapons will pass, and by the 58th century, an AR-15 or AK-47 will be thought of much as we now think of a percussion revolver or Quigley's Sharps rifle.
Thoughts?
