I have a BM carbine w/ the short legnth gas system and I was thinking about using a heavy weight buffer and a pigtail gas tube to slow down cycle speed a little to the effect of improving reliability and wear on my brass.  What do you guys know of the pig tail gas tube and what do you think of such a scheme?  I just want this thing to run as good as my SP1 and I hear that M4's and what not are a little finiky from having been retro engineered from a rifle leghth gun.  

What about using an adjustable gas block to ease the impulse a little?  

Holy sh*t!  They want $90+ for that gas tube!  Must be patented or something.