I have purchased multiple batches of Remington 870P 14" barrels from AI&P Tactical in the US. They were all "Mod" choke. Here is a quote from the AI&P website:
"14" factory 12ga 870 Barrels. Note these are for NFA weapons only. You may purchase one if you are pending your ATF approval if it is legal in your state to even posses the barrel. However, the second you put this on a non ATF approved shotgun you commit a felony. Don't risk your freedom, money and right to own firearms for lack of a $200 tax stamp; Note: All come with fixed Modified choke as that is all Remington Offers. All 14" barrels are Police barrels and have the barrel ring detent plunger. No Remington Police barrel are threaded for choke tubes, none."
Perhaps you have mainly seen the Remington Express 14" barrels. They are more common in Canada, and I believe they are "CYL" .