1)POINT OF IMPACT: In another post, someone claimed that putting pressure on non-ff handguards would cause a shift in impact of 6" at 100 yards...If true, would you call that significant?
[b]Half that is deffinitely true and very signifigant (without FF guards you have to concentrate on not putting pressure on the HG's) [/b]
2)COOLING: Do ventilated ff tubes cool better than the standard HG's? Do aluminum FF tubes act as a heat sink, or is that canceled out by the radiant heat of the barrel?
[b]Yes, Yes, and your better off if it is a highly ventilated FF RAS[/b]
3)WEIGHT: I know that each system has a different weight, but we must also consider the weight of the standard HG parts...in this reguard, Do you think a weight increase of between 1/2 and 3/4 lb. would be justifiable?
[b]Deffinitely you add rails for attachment of flashlights, grips and IR lasers, and you get the benefit of FFing the barrel[/b]
4)STURDINESS: How much abuse can the typical FF tube take? How about simply dropping it: would that cause a breakage?
[b]Dropping it won't break it. I don't really drop my guns often nor does anyone I know so I don't know how many times you can drop them from say 6ft without breaking one (I don't want to drop my rifle hundreds of times to find out either)[/b]
5)CLEANING: I have not heard this adressed. How does one clean the barrel exterior on a FF tube that is not removable?
[b]This is a pain in the ass. you can take your cleaning rod with a patch on it and run it down the RAS and spin it and it will coat the barrel with protecting oil. or if you have a RAS mounted front sight and low pro gas block you can just loosen the collar and take the RAS off. clean it and then put it back on and tighten the collar.
downside to that is that you never have a better than hand tight RAS collar, which means there will be more flex in the RAS than neccassary.
If only they made a rifle length RAS II. that would solve the problems.[/b]
One upper will be a 14.5' light weight barrel "assault weapon" with M68 Aimpoint,
[b]If you never intend to use anything but reflex sights the SIR is a good choice (esspecially the bi-level SIR) but if you even think for a minute you might switch to an ACOG you better get an RAS II or FF RAS MRE, the SIR changes mounting height of the ACOG and that is BS. I really like the SIR but I like the ACOG better, get the MRE if you may want to mount a Bi-pod[/b]
on which I might add a forward grip, and possibly a tac light in the future. The second will be a 20" heavy barrel "designated marksman" type rifle with a TA-31F ACOG, which will prbably also have a harris bipod.
[b]This is pretty simple, KAC FF RAS rifle length, or PRI SPR RAS system.
The PRI system costs more. FFing the barrel is more important when you plan to use a bi-pod - or your prone unsupported and bi-pod supported zeroes may very well be different
If you used a SIR, you would probably wind up wanting a cheekpiece and that may or may not be possible while still providing clearance for the charging handle.[/b]