Need FN/FAL advice

I recently traded my AMD 65 plus about 1k rounds and 8 mags for an imbel build. The rifle has had the barrel cut down to 17", a vortex flash hider added, and a VLTOR rail and foreend put on. The rifle seems to be a dream, perfect length, 20 round mag, rails, etc. The issue I am having is that it either seems to not want to extract cartridges, or it rips them in half. Turning the gas pressure up towards zero rips brass in half, but if I don't have it high enough to rip the brass, the rounds won't extract. In fact, it takes some downright arm muscle to rack the bolt to the rear after firing. All of this is leading me to believe that there is a headspace issue that is causing the cartridges to expand more than they should, and inhibit ejection. Is this a common problem? The ammo I used was Federal xm80cl 149grain, and some Tula steel cased 147 grain. Any advice is appreciated!

Need FN/FAL advice