ORIGINAL: DarZeelon
DS,
Also, because it has an ABN piston-and-liner set, you cannot successfully port it...
The electro-less nickel coating relies on surface continuity, for its integrity.
If you Dremel the ports, this continuity will be broken and the mediocre bond-strength of the nickel to the brass, will allow the nickel to peel off...
If you do think porting the sleeve is within your scope of possibilities, start with a true-chromium P+L set, such as the one for a Magnum/ASP .40 Pro (made by Sanye in China).
The chromium has a superior bond strength to the brass and will not peel off.
Dar, I can't agree with that blanket statement(red).
Myself and others have successfully ported ABN liners, but it is risky for all the reasons you gave. I have raised the exhaust port (and other improvements) )on a OS 55 AX and that was several years and many gallons ago.
A sharp (fresh) diamond burr and diamond jewelers files are the tools of choice. Knowledge of filing direction and how to break the edge of the of the nickel plating may increase the chances of success.
To those that are contemplating porting to the liner AND crank. If you don't know EXACTLY why and what you are doing, chances are that even small changes will do more harm than good, everything is a balancing act. The nickel plating lowers your odds even more. If you are willing to accept this, go for it.