Not getting questions wrong is the best way I know of to score full UMS.
Depending on the paper one has to get so many raw marks to get a E, a few more gets you a D etc. all the way up to A (which is 80% of full UMS). OCR don't (to my knowledge) publish how many raw marks one needs to get to score 90% of UMS or full UMS.
BUT, if you look at the raw marks for each grade boundary, you'd find that they line up very closely to a straight line. If you extrapolate that, you would find the 90% and full UMS raw mark requirements. Doing this for every paper set, you'd get full UMS if you got the following raw marks: 94, 94, 94, 85, 92, 97, 96, 94, 99, 93 (mean 93.8). Not that this means much for this year, but doing some dodgy statistics, suggest that, in answer of your question, getting 94/100 on F322 was on average, maybe, enough to get you full UMS. Similar analysis suggests that 58.6/60 was required to get full UMS on F321. Which does tie in nicely with my earlier claims about how many of our students got full UMS last year.