I agree the the majority of nail stubs used for Forging stub barrels were of the used variety. I can say this because I have had the opportunity to examine a specimen similar to that illustrated in Akehurst book.
This a subject I have researched in the past. Here a couple of interesting findings:
1/ The gun makers of the period used only the best British made horse shoe nail stubs for barrel forging. This was because they were produced from Iron smelted from imported Sweedish ore. The imported ore was for all practical purposes pure iron. Thus by using selected nail stubs the risk of contamination from undesireable elements was minimised. William Greener describes the importance of sorting of nail stubs to eliminate those made from malleable iron. In addition he also desribes the cleaning of the stubs to eliminate contaminates prior to welding.
2/The gunmakers observed that pulled nails were a lot harder than when new. This was important to them because this was property they wanted to develope in their finished barrels. This increase in hardness we know today as, work hardening.The barrel makers learned to recreate the increase in hardness by cold hammering after the barrels were welded.
From some Birmingham price schedules, horse nails were one of the cheapest products that could be purchased from the mills. I have often speculated that the "pulled nail" may have been a combination of pulled and new nails to supplement demand.
Pete
