Could be as little as 2 weeks or as long as 6 to 8 weeks, also depends on whether they have the barrel in stock, sometimes they run out and won't have it available for a while. They've been running 2 to 4 weeks, but with their current shut down, it may be a bit longer for the next few weeks. Give em a call or email next week and ask em, give em your serial number too, the *.243 barrel can't be fitted to all frames.
hr1871@hr1871.com
(978) 630-8220
Tim