Maybe not in the right section, but I'll carry on anyway. I fancied converting my Feinwerkbau P44 to full length with Carbine Cylinder but couldn't source a second hand barrel and a new one was £234 (which made the conversion non viable). How easy is it to machine ports into a Barrel (at the Breech end for air inlet and along the Barrel length for "braking Muzzle Flip") ? I've got a Milling Machine and Lathe and various tooling for both, but am wary of leaving Burrs inside the Bore and seek advice as to "drilling" a hole with a perfect "break through" to the bore. I've thought about tight fitting Brass or Lead Slugs, but is there any other way to do it that I should consider.

Thanks in advance for all helpful suggestions.

Vic Thompson.