Good time of day, y'all!
I'd like to hereby open a rant'n'rave topic concerning rimfire cartridges as a weight-saving measure compared to centerfire ammo, as kind of an alternative to the LSAT program with (probably) lower development cost and weapons of more conventional setup.
I estimate the weight difference due to to be around 30 % due to the thin cartridge base of a rimfire (on a centerfire, it weighs a lot), but I could be wrong.
Feel free to carry together your thoughts as to why such a thing could or could not work, as well as what could be done to make it work.
Some things to think about, pro:
In the past, rimfire ammo was made in calibers up to .50 ballpark, the .44 Henry being a prominent example.
.17 HMR is a rimfire cartridge that pushes its pills at a speed of around 3000 fps, so speed which is very important today seems to be doable with a rimfire; if heavy projectiles that seem to excite all the general purpose cartridge proponents are used along with docile powders and long barrels to make full use of these, it would keep the pressure down.
For military, lower weight means lower log cost, also, the grunts would be happy.
Rimfire tech is well-known, so quicker and cheaper development than for LSAT and little if any development of the weapons firing the rounds.
Lead-free priming compounds seem to be possible today.
Some things to think about, contra:
Priming is less reliable on current rimfires compared to centerfires.
Extraction tends to be less reliable. Both things are a liability, but with a bigger cartridge base diameter, may it be you'd profit from positive scaling effect?
Rimfire, nomen est omen, necessitates a rim that is a bad thing to have on a mag-fed firearm - although this seems to be the smallest problem, as seen on a galore of mag-fed rimfire weapons, mag capacity ranging from five to hundreds (for the American 180).
According to Wiki (yes, I know... But proper info on anything rimfire seems to be so arcane for some reason...), priming compounds for rimfires need some kind of frictionator which consists, mostly of ground glass - not good for barrels, probably also not so good for the shooter if the glass particles exiting the barrel get inhaled.
So, what's the state of the art and what's in the making with rimfires?
EDIT: For clarity, i don't mean existing rimfires such as the .22 LR but rather theoretical cartridges analog to current centerfires.
Edited by Blunt Eversmoke, 22 July 2017 - 0601 AM.