Whenever thoughts have to do with balancing acts, I refer to my old stand-by, the baseball bat. I think it's appropriate for this situation.
The only thing you're trying to do is balance the bat, on end, in the palm of your hand.
- With the heavy end down, it's really difficult for any length of time and invariably gets out of control.
- With the light end down, it's quite doable for a lengthy amount of time.
Now lets add a pin perpendicular to the side of the bat about a quarter of the bat's length from your hand. We'll imagine the bat is a bolt carrier with an attached gas key.
Again, do the balancing act. This time, however, apply an upward force to the pin with your other hand, mimicking pressure exerted on a gas key during the bolt cycling.
- With the heavy end of the bat down, the force you exerted on the pin quickly destabilizes the bat before any appreciable lift is transmitted to the bat itself.
- With the heavy end away, and the pin on the light end, the bat is cleanly lifted from your palm.
What this demonstrates to me is that the rear of a bolt carrier needs to be heavily weight-biased to address any concerns of balance.
It's about controlling the pitch or levering off axis, is it not?
At that rate, and considering the design of the carrier, I don't think they can put enough weight on the rear of the carrier.
........
The baseball bat analogy, if you will, originally came about when discussing motorcycle dynamics. Some were saying you had to put weight low, others said it was better to have it high. The baseball bat immediately demonstrates the fallacy of putting weight low on a motorcycle if you understand the principles that keep it upright.
Extrapolating from the errant motorcycle designer's mistakes and applying them to a bolt carrier, perhaps they thought lighter was better.
"Sure, we can improve cyclic rates, wear-n-tear, etc."
Did they take into account side loads when they considered reducing longitudinal loads? I think they've only served to relocate the wear-n-tear, and increased side loads is not something I want running down my rails, if that's the result of weight reduction.
I consider myself a smart guy, albeit, uneducated. Regardless, the original designers of such great platforms as the AR, 1911 and M2 had to have made compromises in the designs. What is acceptable wear? What can be done to mitigate it? Does that adversely affect other components?
These original thinkers, I'm sure, asked themselves way more esoteric questions than I can even begin to imagine. To think that new technology somehow makes things better is arrogant without going back to the drawing board of the original design and understanding why the compromises were made. Yeah, making a trigger slicker makes sense, to a point.
Making a bolt carrier lighter and slicker seems to make sense too, but what have you done in consideration of the rest of the action and its new affect on the platform?
I think you could have a serious conversation with these guys. Popping a new idea, or another way to think, into people's heads is not unheard of even if the recipients are "industry experts".