Kassim Ouma threw quite a few, maybe Paul Williams, and one that often gets overlooked, Sweet Pea in his prime could very well throw 75-100 punches a round.
Tommy Cordova and Danny Lopez regularly threw over or close to one hundred punches a round. I also recall seeing several instances where both Myung Woo Yuh and Thierry Jacob easily threw well over 100 punches a round in some of their bouts.
Rocky Marciano threw 96 punches in the 15th round after 14 gruelling rounds with hall of famer ezzard charles. when you consider about 80 of them were power punches, its simply amazing. Anyone know how many punches rocky threw in round 6 vs archie moore? had to be close to 100.
Jimmy Carruthers is alleged to of thrown 110 punches in 100 seconds in his one round beating of Vic Toweel.
HW Rocky Marciano is said to have the quickest hands but there are no stats. Cristobal Cruz threw the most in a championship bout: 1,580! Willie Pep is said to have thrown 200 punches one round.
One that was pretty amazing to watch was one fight between Philip Holiday and Ivan Robinson, about 10 years ago, where I think both were doing close to 100 punches per round, every round. Robinson finally started to fade a bit in the last couple of rounds and Holiday outlasted him.
I believe the heavyweight record for most punches thrown in a single fight is still held by David Bostice. In a 10-round win over Ed Mahone, he chucked 1044. An average of 104 per round of course, and he'd have to have had several rounds with more than 100 thrown to get that. No other heavyweight, even in 12 fights, have thrown more than that. But bear in mind that's only on official record... Seem to recall Sedreck Fields threw an ungodly about of shots at Shannon Briggs too. Rahman had 933 against Toney in their first fight for an average per round of 78. Lou Savrese had a high figure against Foreman too. Have to dig around for some. See if I have any stats for exact rounds as well.
Okay...here's a load of heavyweight stuff I dug up. It's not inclusive by a long shot, for example I don't have the stats for the busy Round 10 of Holyfield-Bowe I, but it's what I've found from the stats I've got. Some numbers to add to the mix, and I'd be more than happy if anyone has any data to add or overrule anything here. ---Highest punches per round--- Bowe vs Holyfield III 45/91 (Round 3) Grant vs Savarese 56/90 (Round 10) Bowe vs Holyfield II 38/90 (Round 4) Bowe vs Holyfield III 57/89 (Round 5) Bowe vs Holyfield II 30/87 (Round 10) Lewis vs McCall II 34/78 (Round 3) Bowe vs Holyfield III 33/76 (Round 4) Lewis vs Briggs 52/74 (Round 4) Grant vs Wooden 47/73 (Round 8 ) Lewis vs Tua 25/73 (Round 1) Others : Holyfield vs Bowe II 43/70 (Round 4) Tyson vs Nielsen 29/63 (Round 1)
And some fights with a high average of punches per round... ---Highest average--- Ibeabuchi vs Tua 27/81 (12 rounds) Rahman vs Toney I 23/78 (12 rounds) Savarese vs Foreman 28/73 (12 rounds) Bowe vs Holyfield II 29/66 (12 rounds) Tua vs Ibeabuchi 24/63 (12 rounds) Bowe vs Holyfield I 30/59 (12 rounds) Wladimir vs Byrd I 20/59 (12 rounds) Lewis vs Tua 25/56 (12 rounds) Lewis vs Holyfield I 29/51 (12 rounds) Holyfield vs Foreman 30/49 (12 rounds) Holyfield vs Holmes 21/45 (12 rounds) Holyfield vs Bowe II 21/43 (12 rounds) Bostice vs Mahone ---/104 (10 rounds) Fields vs Briggs ---/89 (10 rounds) Rahman vs Lawrence 34/82 (10 rounds) Rahman vs Tua I 30/76 (10 rounds) Grant vs Abdin 25/69 (10 rounds) Rahman vs Sykes 22/63 (10 rounds) Grant vs Savarese 27/59 (10 rounds) Lewis vs Mercer 24/53 (10 rounds) Grant vs Wooden 26/51 (10 rounds) Tyson vs Green 28/46 (10 rounds) Holyfield vs Mercer 22/44 (10 rounds) Tyson vs Tillis 18/44 (10 rounds) Bowe vs Golota II 24/53 (9 rounds) Bowe vs Holyfield III 32/66 (8 rounds) Rahman vs Maskaev I 23/60 (8 rounds) Lewis vs Jackson 31/59 (8 rounds) Bowe vs Coetzer 35/61 (7 rounds) Wladimir vs Brewster II 33/72 (6 rounds) Wladimir vs Mercer 32/72 (6 rounds) Tyson vs Ferguson 27/44 (6 rounds) Grant vs Izon 22/65 (5 rounds) Holyfield vs Czyz 34/64 (5 rounds) Wladimir vs Brewster I 24/62 (5 rounds) Lewis vs Briggs 33/52 (5 rounds)