Not really. Most CF filaments are PLA with a chopped strand fibers added in, and the strength gains are marginal.

You can get CF-impregnated ABS/ASA but it’s really hard to work with and liable to be weaker unless you get everything perfect.

Ultimately the best approach is to go the same route as the Defcad people, printing the lower receiver of an AR and paying cash for the rest (or maybe also stock and frame. The important bits line the breach block, barrel and other things that get hot would still be metal.)

The thing with that is that the LR is technically “the firearm” as far as the ATF is concerned.