These fit mt DIY rods in Hickory and black GRP can be tipped with a covered screw or a shotgun ram.
Ampco, a product of the the American Alloy manufacturer of that name, is used in rifle, pistol and musket/shotgun nipples and come in 40 sizes/thread variations.
Ampco is a tough copper based alloy, with a tensile strength of 118,000 psi for resisting repeated hammer blows, somewhat higher than most steels used in muzzleloading barrels. High thermal conductivity gives fast heat dissipation, reducing erosion, and the small base hole (28 mils / 0.028 inches, Pedersoli use 25 mils in their Beryllium nipples but they cost at least twice as much) reduces blowback and cap disintegration. These are very popular with Ruger owners, replacing hex with standard Nº. 11. I pop mine in the lathe and make the tops conical for quicker, easier capping. Good fit to replace .225” - 32 Original Colt and Remington nipples and Enfield 5/16 x 18. These fit Monkey Tails, in both No.11 and Top Hat.
Pyrodex users may need to increase the size of the base hole to achieve reliable ignition. Five vents are also available.
I have some of all three types of nipples for the Beaumont Adams (as originally manufactured by Adams, Callisher & Terry and Pryse & Redman) using one of the harder Ampco alloys.
With the increasingly high cost and rarity of good flint Agate flints are worth a mention because they can be resharpened on a diamond stone which is also available at a surprisingly low cost.
Ted Cash makes No 10/11 cappers in matt or shiny brass and German Silver for the Rifle (holding 75 caps) and the Curly (100) for revolvers, TC is no longer available. Cash Straight line come as Winged (12), 209 (12) but I prefer the Brass Pedersoli Remington (20), they also do them for Colt (20) and Zouave (approx 12) for musket caps without wings.