So everyone knows, I never meant for my last post to be a statement of impossibility, just that I didn't realize the plausible value of such a rifle, and the fact that a bolt-action .300 is the largest i have dealt with. You could always use a piston system for it instead of DI, eliminating the need for a vent. Seeing as I have never actually fired an 82A1 (as much as I would love to), I can't really relate to the felt recoil element of it, unless someone could make a comparison between an 82A1 and a 6-7 lb .300 Win. I would think the side charging might be best, as optics on the rifle might make it a bit difficult to reach a standard charging handle, unless you mean top charging like the HK93 or FAL.
I have to agree with you on trying to make it to prove it can work instead of simply saying it can't based on theory, but with one caveat. It's best to prove it by the attempt, so long as it doesn't blow up in your face. I'd love to help if I could, and more power to you if you can make it work.
Don't worry. I caught where you were coming from. I was just trying to stop a routine debate before it gets started. I'm use to being told things can't be done and usually prove them wrong anyway, leaving the debate a pointless conversation. It's getting old and routine and I don't have much energy for these debates anymore so I was just making sure one didn't get started.
I would think that an AR platform .416 Barrett rifle with a 25in barrel and weight of 15-17lbs would be extremely handy. For one thing it'd be allot cheaper. I am looking at a total budget of less then half of what a Barrett 416 costs and that's for a 1 time build and all the research that goes in to it. I should also mention that I am looking in to make my own magazine out of plexiglass and replacement Barrett innards, leaving a much smaller and easier to handle/carry magazine then the 82A1 mag. You'd be looking at an all around more practical and mobile rifle.
The 82A1 is a push. The day I fired it we had an M-4 carbine at the range as well. The 82A1 was obviously heavier but the M-4 clearly had more punch. Think of a big 30lb crutch scooting back at you as if someone tripped and fell against it and you'll have a good idea what the 82A1 kicks like. I've never fired a .300 Win Mag rifle but from what I've heard about it, it sounds far worse then the 82A1. The M-1 Garand is probably 3x as bad as the 82A1.
The reason for side charging is due to the outer layout of the gun. The same stock set I am doing for the AR-15, I am going to build as part of the design of this gun, if I build it. The AR-15 stock set got allot of time on the drawing board dedicated to making it work with the AR-15's charging handle and ultimately made some sacrifices to make it work. If I'm building a unique rifle system that isn't compatible with others, then I am going to do as originally intended rather then make sacrifices.
Piston systems are heavy and I only know one manufacturer who has managed to make a gas piston AR type rifle that uses a gas piston system without sacrificing accuracy. On top of weight savings and accuracy benefits, a side-venting DI system will probably be allot easier to pull off, especially if it uses a side-charging handle, which is probably half the work by it's self. People blame DI for the reliability problems with the AR-15s in the past. After looking deeply in to the weapon and how it works, I've found allot of areas it's reliability could have been jeopardized by cutting corners, but never any evidence that DI alone is going to have any significant effect on reliability. At least for 1500-2000 rounds. FWIW, I personally have a gas-piston AR--15. Even though it's a gas piston rifle, I actually chose to go with it mainly because of my familiarity with the makers and trust in them, the parts quality, method of construction and overall performance of that particular AR variant. The only thing the gas piston really means to me is that I have to clean it less often.
BTW. The .416 Barrett, at least from what I understand, has very similar gas pressure to the AR-15, so very little about the gas system would actually need to be changed. Even so, the beauty of gas systems is you can tune them to work for just about any pressure, so long as it's enough to charge the action. You can always vent it down to whatever recoil force you need.