AR15 pistol upper build

[RoadRunner]

I am planning to build a 10.5" pistol upper. The only 10.5" barrels that I can find have a carbine length gas system. Will this cause a cycling problem?

 

[CyberWolf]

I am planning to build a 10.5" pistol upper. The only 10.5" barrels that I can find have a carbine length gas system. Will this cause a cycling problem?

Not necessarily, no (should be fine).

Obviously there's a handful of variables involved, but I've got a similar build that runs like a top (chopped a 16" bbl with FSB/carbine-length gas down to ~10.5")

 

[RoadRunner]

Not necessarily, no (should be fine).

Obviously there's a handful of variables involved, but I've got a similar build that runs like a top (chopped a 16" bbl with FSB/carbine-length gas down to ~10.5")

Thanks.