I would never exceed the manufacturer's recommended maximum charge without working up in .2 gr increments using new or once-fired brass, all of the same manufacturer and lot. Inspect each and every spent case for signs of excessive pressure at each .2 gr developmental increment. Cartridge overall length becomes critical as the load pressure reaches the operating maximum pressure. Use a chronograph to check velocities and stop when you have achieved your velocity goal. Loads developed over the maximum recommended charge weight should never be fired in an alternate firearm without redeveloping the load. Likewise, if you change primer brand, case brand, powder lot, or ambient air temperature, you must redevelop your load. Unless you have a firearm with a compensator such as a USPSA Open Division handgun, I would not even go to all of the trouble.
A better solution is to pick a powder that you can use to achieve the desired bullet velocity without exceeding the manufacturer's recommendations. I prefer handloads that duplicate factory specifications in both pressure and velocity. Making major power factor can sometimes be a problem with certain firearm/ammunition combinations but a chronograph will provide the necessary reassurance that you have the velocity that you need to make major with a given bullet. For some of us, finding a place to use a chronograph can be a problem as busy public ranges often slow productivity to a crawl. Also, not all powders are readily available.
Select a suitable powder/bullet combination and do your homework! Good luck and safe shooting.