>Well, aside from disadvantages of gas systems with their tubes, gas ports and such, i don't the intertwined nature of such systems, they all have to be too fitted together and have all these spaces, grooves and cavities inside that i don't really trust. That's why i like blowback systems - they don't require you to modify the barrel, keep pieces isolated, separate and simple, so that you can approach the weapon part by part and fit or overview any of the elements separately. Maybe it's irrational but i just don't find gas systems as trustworthy.
That's understandable to a point, I guess. I do agree that blowback and delayed-blowback are criminally underrated systems and need to be looked at more, but we shouldn't overlook the fact that gas operation and gas-delay have their place. In longarms, the gas piston–or more correctly, the many-lugged rotating bolt that gas systems operate–lends itself very well to accuracy, because the lock-up is just so damned consistent. Since blowback bolts just rest against the breach with no real locking mechanism holding them in place, they have a less consistent lock-up, which lends itself to worse accuracy. Obviously, this is partially offset by the weight of the gas tube interfering with barrel harmonics, but this can be mitigated by supporting most of the piston weight from the receiver, or indeed moving the piston inside the receiver completely. This is what the Stoner gas system, with its piston integral to the BCG, does. The gas tube and block weigh almost nothing, so they contribute almost nothing to barrel harmonics. And you can see this reflected in the precision of ARs–you can get sub-MOA performance out of the box from a $600 rifle. Don't get me wrong, delayed blowback is definitely better for an SMG than gas. Just don't discount it entirely, the system has its place, as overrated as it is.
As for gas-delayed blowback, I think it can be especially useful in pistols, because the piston directs its force in a direction opposite the movement of the slide, which reduces recoil. Seeing as the pistol rounds this project is using are on the hotter side (not unmanageable but definitely snappier recoil), I think there's some merit to using gas-delay in the pistol, especially if the frame is lightweight polymer.