John. Burnham/McGuigan's Facts lists and trivia p188-190 says head gear was funded by the regiment (Colonel) not the government so there was a little flexibility perhaps. They don't give the frequency of replacement of shakos but state a dragoons 'watering cap' (quite close in design and manufacture) was only replaced every four years. Paul

I think that it seems a reasonable proposition that the regiment was using up old caps from store/

My understanding was that caps were part of a soldier's necessaries, (i.e supplied by the Colonel acting for the government but paid for out of the soldiers' pay), meanwhile the grenadier caps- for example- were regimental property. However, that might have changed during the period.

In any case in the regulations drawn up in 1802, it was ordered that:

"Caps made of Felt and Leather with a Brass Plate, Cockade and Tuft (conformable to a Pattern left at the Controller Office for Army Accounts) to be Worn, instead of Hats, by the Non-Commissioned Officers, Drummer Fifers and Privates of the Guards and be every Description of Corps of Infantry, excepting the Highland Corps, who are, when in Europe, N. America, to continue to wear the Highland Bonnet, but when in the East and West Indies, are to wear the Felt Caps similar to other Regiments.

They are to be made of sufficient Size to come completely on the Head. To be worn Straight and Even and brought well forward over the Eyes. The Felt Cap and the Tuft is to be supplied annually. The Leather Part, Brass Plate & Leather Cockade once in every two years. It is permitted to Engrave the number of the Regiment of each side of the Lion, on the lower part of the Brass Fronting and those Regiments that are entitled to Badges are permitted to bear them in the Centre of their Garter."

(SEE: Carman, W. Y. (1940), ‘Infantry Clothing Regulations, 1802’, Journal of the Society of Army Historical Research,
vol. XIX, pp. 200– 235)