So I brought this post to Seekins attention. First and foremost Justin is the FNG and was only replying as he was instructed about available inventory.
As for the reply itself, yes he needs to work on his bedside manners.
Due to the current SP10 Rifles using the same barrel contour as the SP10M the allocation of available barrels to the general public has changed, and has affected current inventory.
What Justin said is true, the SP10 can be easily be rebarreled with a wide array of barrels that are available.
@Jsp556 if you would like me to rebarrel your upper id be more than happy to discuss it with you. Just cover parts and shipping.
Jake