As a further footnote, A DRY chain will stretch enough in 500miles to jump a tooth on your front sprocket (and break your clutch pushrod)
That happened to me when I first bought my bike. My Scottoiler ran out on my way back from Hamburg. I think the previous owner had been using old engine oil in it, which is way too thin, so once empty the chain dried very quickly. My clutchrod went just as I got to the M25.