I think someone mentioned this but I couldn't find the post. 2 of the barrels I just got happen to be on the recall list. here is the info from their website. They also have a precautionary recall listed in small print at the bottom of the page for other barrels . If you have any drop-in Green Mountain barrels for your gun you might want to check the serial number. They don't seem to be contacting anyone, I just happened to be on their site looking for another barrel. Here's the info
Notice to owners of our Black Powder "Drop-In" barrels: There is a possibility that the nipple on your rifle is defective. Metric threaded nipples were inadvertently installed in some barrels instead of the proper 1/4-28 threaded nipples. The serial number range in question if for percussion barrels # 030672 - 031352. Do not fire this rifle. Please contact us at 603-447-1095 x18 or
ksmith@gmriflebarrel.com to arrange return shipping. The barrels will be inspected and if found compliant returned. If they are discrepant the breach plugs will need to be replaced so bear with us as this may take a while to complete. We apologize for the inconvenience.
This is the info on the precautionary recall:
Product Recall Notice Green Mountain needs to do a precautionary recall on some of our Thompson Center drop-in barrels. If you have a barrel in the following Serial Number range 026220-027303 please contact Kerry Smith at (603) 447-1095 x18 to make arrangements to have your barrel returned for inspection. Thank you and we are sorry for any inconvenience this may cause.