Found the following.Sounds complicated.

A method of forming rifling, including that of a gain twist configuration, the chemical milling process in the bore of a barrel which may include a liner of a refractory material. A template rod made of an acid resistant material which is radially compressible and which has a diameter slightly greater than that of the bore is pressed thereinto so that liquid tight contact is made between the surfaces of the rod and bore. A plurality of spiral channels and uninterrupted areas are formed in the rod to image the desired rifling configuration. A closed circulatory system delivers fluid acid to one end of the channels, and the rifling grooves formed thereby, and after passing through returns the acid to the pump for recirculation. A pressure gage between the pump and barrel may be used in lieu of an elapsed time for chemical reaction to indicate when the rifling grooves are formed to the desired depth.

This is one of a number of new "modern" designs, desperately striving to create a new generation of what Kalishnakov already created. An efficient battle-rugged combat rifle. But what Kalishnakov could not do with his technology was build a light weapon with hightech adaptability.

As far as "new" manufacturing technologies... {yawn}... with our current manufacturing technologies (although this acid technology is creative) the main issue is mostly a weapon system design problem.

Here is the thing: Ever since the invention of our current copper-cased gunpowder and lead projectiles, the design of weapons has been around this type of ammuntion. And there is only so much you can do to maximize this type of ammunition.

Think about it. Through time, the greatest technological jumps in weaponry have been new developments in projectiles and ammunition. The delivery system improvements that follow have been little more than gradual improvements on existing technology.

Let me ask, what is the greatest improvement from Springfield 30-06 to the AK-47? Same caliber and same basic ammunition technology, and similar basic combat ballistics. Only significant combat advantage is that AK-47 shoots faster.

AK-47 to M-16? Main advantage to the M-16 is weight and cheaper ammunition. In combat the AK-47 still has better effective combat ballistics.

The Kel-Tec RFB referenced? It is lighter and compact, and hopefully more accurate that an AK-47. But in combat, effective ballistics is still relatively equal to AK-47.

So... until I see a major advance in ammunition technology these new weapons and manufacturing advancements are not necessarily all that impressive when it comes down to basic combat effectiveness.

To be sure, there's only so much you can do with a bullet. I think the next innovation will be some sort of electromagnetically accelerated bullet, if battery technology improves enough.

The beauty of this weapon is its simplicity compared to the M16 and even the AK47. There is no long hollow gas tube. It works with a short-stroke piston like the AK, but there's no rotating bolt assembly - just a simple tilting block. You probably don't need a lathe to make it except for the firing pin and gas pistons. Machining the bolt could possibly even done with a dremel and a bunch of bits. No large blocks of metal appear to be used for the receiver, so the rest of the work could be done on a very small mill, one just large enough to machine the bolt. A FAL bolt could possibly even be used since a FAL works on a tilting block action of the same caliber. The bolt carrier is "trapezoidal sheet metal." I think the receiver is sheet metal as well. Though it can be tricky to bend sheet metal, but it can be done by hand.

BTW, don't 7.62 X51 mm rounds have about twice the energy of the 7.62 x 39 mm rounds that the AKs use?

Very true, Walt. This Kel-Tec RFB represents a number of significant improvements in design and manufacturing.

My main point which I bury in my diatribe is that we are still pushing a 30 caliber lead bullet at the enemy. (A range of 20 to 50 callibers, in general). Regardless of how we launch it the results at the end are relatively the same.

Significant improvements in my book are:
-Launching pre-formed metal balls instead of rocks or wooded shafts.
-Gunpowder
-Rifled gun barrels
-Mini" ball.
-Brass cased ammunition.
-Breach loading.
-Engineered ballistic bullets.
-Multi-loading "repeaters"
-Automatic "repeaters" (eg: AK-47)
-Armor piercing and depleted uranium rounds.
-Automated and/or high-tech targeting.

I am not including "Weapons Systems" in the above list. While being obvious advances in weaponry, they require a crew and extensive support to deploy and operate.