Now I am still "green" however I do believe the issue you described would be what you think not enough force driving the slide etc. However I DO NOT think the answer is going to close to max right off the bat. I would think the better idea would be to work up as is suggested in all the reloading manuals I have read. It could be simple as just .2 more of a charge and you would be golden for reliability not always for accuracy. I would work up a couple loads of differenct charges.
But just jumping to near max could be very bad of a idea as your weapon may not be able to hold that pressure very well. Hope this helps and is close enough to correct to cause a issue.