Maxim explained us several times that balanced actions are not enough for energies much higher than 5.45 ones.

I wonder if a short recoil variant of a based on a reduced-rate gast design would do the trick: since barrel and bolt carrier would return during some distance and at the same time other barrel + bolt carrier group would advance, it would compensate much more than just short recoil design as Beretta's, right?

Besides, two pencil barrels would add a little weight, not much more that a heavy-profile barrel, and such weight increase would help in taming recoil

I think that double barreled assault rifles were not a thing because of the 2300-minus recoil. But now...

Welcome to the mad ideas club! This is truly fascinating. How would you feed it?

two straight magazines inserted into two magazine wells. Something like TKB-059, but optimized for recoil mitigation instead of rapid salvos a la SPIW. Indeed it would be optimized for semi auto fire instead of auto fire, specially coupled with future FCS. Recoil mitigation would reduce fatigue and time between single shoots

two barrels = inherent problems with single-shot accuracy and expensive and complex co-zeroing process.

No headpats.

I thought about some general principle comparable to AEK-971: two or more syncronizing gear, but this time between barrels. Optic mount should be in the middle of both barrels, and each barrel would shoot offset to the right or left. It should be assumed that, all other things equal, impacts would be inside an ellipse equivalent to the distance between barrels' centers. Such ellipse shouldn't vary with the distance unless I didn't consider some factors (something actually probable :) ).

Something like a gilboa snake, but with a short recoil  + gast system and the two pencil barrels synchronized and with smaller distance between them

Even assuming that you could get this to work you're still creating a lateral distance in both barrels and mechanisms over your hand and wrist which will induce some interesting torquing effects etc.

Bottom line here is that this is bound to create a whole bunch more problems than it could ever possibly solve.

In semiauto this is going to be even more pronounced.

To be blunt, this is the kriss vector all over again only worse.

Hey, thanks. I appreciate a blunt but solid criticism. I was conducting a non-calculus gedankenexperiment with some abstract pieces and principles.

They have to do something new with such 4 kJ

Now, if gears are quite separated from the shooter, as close to the muzzle as physically feasible, then torque would work against body mass instead of against the hand at the pistol grip.

But if short recoil work with the entire bolt carrier + barrel block for a while, part of the recoil energy will be invested during that part of the returning movement. And if another block is working on the opposite sense, then what would happen with the energy when bolt carrier strikes the buffer?

I think that no matter how you tried to arrange it you'd get weird off axis torques and acceleration which likely wouldn't be helpful...

But let's step back from the gast mechanism for a minute and look at the ngsw itself and it's 4000 joules.

Once you combine a smuzzle type suppressor/brake hybrid with even an fg42 style stock buffer along with any number of other strategies in the gun design itself (as an example the textron guns extremely light operating parts group) you come up with something that's very much in the manageable range.

At absolute worst you always have the option to decrease the suppressor efficiency and thereby increase the amount of recoil your muzzle brake can bleed off. 

Because all of the ngsw guns are working with pretty significant muzzle pressures you could conceivably bleed very high double digit percentages of the recoil energy off while still keeping the guns hearing safe at the ejection port.

And realistically that IS an option. The days when electronic ear protection and shooting eyewear were expensive and hard to mass issue are gone. Granted, if you find yourself in this situation you're gonna get fairly unpleasant over pressure "slap" especially in certain shooting positions but not so much as to make it unworkable.

Since I brought up electronic ear pro I'll add one other factor that's likely to aid greatly In making a 4000 joule fire breather have good usability.

The ngsw fc with it's disturbed reticle, built in range finder, digital hud, and etc will also very much help guys make quick and accurate follow up shots. Put simply, technology may actually sufficiently compensate for a hard to handle gun in conjunction with the other factors to still make it usable and even competitive.

Finally you have the armor and etc guys wear these days which will also help take some sting out of whatever excess recoil energy other stuff doesn't mitigate.

Im not in any way saying that any part of ngsw is ideal by any means. 

But it's also not so far out there and potentially unmanageable that it will require radical solutions like a gast mechanism.

roguetechie said:

At absolute worst you always have the option to decrease the suppressor efficiency and thereby increase the amount of recoil your muzzle brake can bleed off. 

My original thought was a G11 style mechanism that allowed it to fire full auto as soft recoil and single shots as dampened.  Basically a 3 to 4 cm movement of the barrel, action and magazine with the movement being backwards a few cm to mitigate the peak recoil of single shot and on the forward movement on full auto as soft recoil. The CT round is reasonably squat so a rotating chamber and vertical feeding from a magazine parallel with the barrel could well work. 

Still an incredibly stupid and over complex idea, but workable. The main advantage being less muzzle blast being directed back at the shooter because the muzzle brake is not as critical.