[Ultra Tech] Increased Firearm Power with TL

[Rupert]

Originally Posted by Varyon

Although maybe part of the necessary changes to get better performance is a heavier (and thus probably longer, given constant caliber) bullet, which may not feasibly fit in a typical cartridge?

A longer case, and/or overall cartridge length is not an issue in terms of the tech. It's a small issue when it comes to use (but really not one at all for battle rifles and machineguns). Mostly it's an issue with manufacture because it means all new receivers and bolts, etc., and the US arms industry is very heavily invested in standard M16 sized parts, and they don't have enough length for a longer (say .30-06 or 7.62x54mmR) cartridge.

There may be issues with exceeding certain speed limits, in which case you'd increase kinetic energy by using a heavier bullet instead.

Barrel wear is the big one, it it'll be worse when gaining your velocity through pressure rather than through long barrel length and slow-burning powders (the invention of which in the 50s and 60s had a lot to do with the proliferation of big magnum hunting rounds, BTW).

I think the .220 Swift is regarded as the fastest bullet on the market, and is typically around 4,000 fps (a 23% increase compared to the XM193, 33% compared to the SIG Fury), while there are apparently 4,250 fps (31% / 42%) versions available, and apparently handloaders can get it up to 4,500 fps (38% / 50%).

Barrel wear is ferocious, you need a long barrel (26" is standard, as I recall), and the Swift is simply not as accurate as the .22-250 (though the latter's more modern case design doubtless helps with that), a comparable though slightly less powerful cartridge.