I did this the entire way to completing both of the overkill challenges (tier 6) and ended up with 1660 bullets. It's not that effective.
The best thing to do is stand in front of sentry guns, but even then it is going to take a long, long time.
I am currently working on this myself, if i still had to prestige i would not normally bother,but getting to 20th the game seems a bit stale so all thats left is the titles and challenges of weapons i would not normally bother with,its actually quite fun once you get used to the shield, i often hear the player i have just knocked down cuss, lol
They sure do cuss us riot shielders alot bet most of them were probably snipers.
Since undertaking this challenge I've found a few ways to help speed things along. Below are 3 setups I'd recommend using depending on how you want to play the game. All setups are for dropzone and all killstreaks are set to assault with sentry gun, attack helicopter and pave low (not sure if this matters so much in dropzone but I like to think it increases my odds of these showing up in a game).
#1 : Riot shield with melee + a pistol + throwing knife + smoke grenade, sleight of hand + blast shield + steady aim (This setup allows you to gain control of the dropzone)
#2 Riot shield with melee + pistol + throwing knife + smoke grenade, scavenger + blast shield + sitrep (This setup allows you to gain control of the dropzone + detect enemy traps + If your good with knives humiliate the enemy)
#3 Riot shield with speed + a silenced pistol + throwing knife + smoke grenade, sleight of hand + assassin + steady aim (This setup allows you to concentrate on deflecting bullets from killstreaks while remaining under the radar)
P.S. 47545 bullets deflected sofar ( only took 2 months & I'll be finished in 2 days max )
got mine in a few hours in clan ops, because when our team was active we had only one shooter and the rest would have riot shields lol that way you destract the enemy players to try killing you other than the one without a RS :-D
its a good tip, get a team of 6 and try it out
Can't believe they still haven't fixed this; either tone it down to a more reasonable number (5-10k bullets), or at least make the count persist through prestige. 50k bullets is order of magnitudes greater than completing the other two shield challenges (block 50k damage, and deflect 100 explosions). I hit 50k damage blocked while only having 1150 bullets blocked....ridiculous. Please fix it devs.
I was 10th Prestige, the highest Prestige level at the time and I had about 8,000 bullets to deflect left before earning the Title. Then Infinty Ward added five more Prestige levels and I was dumb enough to Prestige right away before considering the consequence of the Riot Shield Challenges resetting.
I really regret that.
Seriously....I'm about to hit prestige 18; there's no reason that any of these title counts can't be made to roll over when you prestige, such as the weapon kill counts do. First time I started working on some of the support titles I got a rude awakening when I prestiged with 135 recon drones called in... I figured sweet, I'll prestige and pick up the next 15 then have my title and move on to something else. But sadly, it started from 0 all over....calling in 150 recon drones isn't fun.... neither is trying to pick up 50k bullet hits on your shield when if you're lucky you might pick up 200 hits a game. Please fix this devs.