"The heavier bullet has greater inertia and generally a longer bearing surface and thus resists being accelerated to a greater extent than a lighter one. This means that the pressure will drop off from peak chamber pressure at a lower rate than with the light bullet.A higher port pressure will still be harder on the gas system, even if the port is only open for an instant, because the gas pressure will accelerate the piston more rapidly and thus strike the operating rod more forcefully during the brief period that the port is open to the barrel and not closed off by the piston"
I thought about this... In the same way that we vary the powder loads to regulate chamber pressures, the bullet also controls these pressures. The heavier bullet requires less powder to get the same pressures due to the longer burn time.
I suppose it could be tested whether pressures are still climbing by stretcing a cloth about 3" in front of the muzzle and shooting through it with both heavy and light loads. My guess is that there will be more residue on the cloth from the lighter (bullet) load, indicating more unburnt powder. If that is the case then the heavier load burns cleaner, and the pressures are quicker to reach maximum and stop climbing. Of course this could be better tested with guages, but we don't all have those...plus the guage will only tell you pressure, not anything about the burn.
May have to try that. At this point, merely for curiosity purposes.....
I thought about this... In the same way that we vary the powder loads to regulate chamber pressures, the bullet also controls these pressures. The heavier bullet requires less powder to get the same pressures due to the longer burn time.
I suppose it could be tested whether pressures are still climbing by stretcing a cloth about 3" in front of the muzzle and shooting through it with both heavy and light loads. My guess is that there will be more residue on the cloth from the lighter (bullet) load, indicating more unburnt powder. If that is the case then the heavier load burns cleaner, and the pressures are quicker to reach maximum and stop climbing. Of course this could be better tested with guages, but we don't all have those...plus the guage will only tell you pressure, not anything about the burn.
May have to try that. At this point, merely for curiosity purposes.....
