That would be my guess as well. I know I have several rifle barrels inletted into stocks waiting on me to get to them. When I do this I mark the barrel & breechplug the same, because each plug is mated to each particular barrel & I want to be Sure they go back where they are intended. I usually put the serial number the rifle will be on the barrel bottom flat & the breechplug, then put the breechplug in a container with the lock & all the other misc. parts for that build.
One time I had 6 stocks shaped & barrels inlet, but forgot to mark the plugs & barrels. So I had to take them all back out of the stocks, fit each plug to Be Sure it was right, etc. From then on I mark the barrel & plug when I take the breechplug out.
Keith Lisle