I have tried the Hornady 6.5 (.268) ammunition in two Carcanos. A Carbine and a short rifle. The Little carbine ( folding bayonet) shoots to the sights well and groups very well. the other shoots erratic. I have not signs of pressure. i have not used it hand loading. I have some other custom made .266 diameter spires that I have tried, but not with these rifles. The short rifle I have tumbles with Privi, Norma and any .264 load I have tried. The Privi ammon in my rifles show much in the way of pressure sign.