Call of Duty: WWII

This is easiest solo since the zombies won’t split after another player when trying to group the horde around the bomb.

Easy solution: Re route power from the laboratory to the morgue and open the door to the salt mines. 3-5 bombers will come strolling out. Lead them up to the main area where you turn the valves. Activate camouflage. Shoot off their small heads, which will make them drop the bomb. Their small head only takes one bullet. Once you have all 4 bombs on the ground, you have multiple opportunities. Get a full horde trained up and blow the bonb up once all of them are circled around the bomb. I did it on round 11. After helping some people out it seems there has been a patch that nerfed the bombs power so do this on round 7 or 8, as early as u can set it up. I got 13 kills off of my first bomb. According to dj koolade, insta kills don’t work on this achievement.

heya guys ... so this achievement can be tricky but you just got to open up the salt mine doors then you will have 4 bomber zombies spawn , so shoot them , train zombies around their bombs that drop and then just shoot the bomb ... sounds simple but its more tricky so i made a video guide showing you how its done :)

Edit: I finally got it by accidentally shooting a bomb on the ground. This achievement seems very glitchy.

A bomber is the zombie with a bomb on it's back that explodes when you get close, explodes when you shoot the bomb on it's back or drops the bomb on the ground of you kill it without hitting the bomb. I've killed groups of more than 10 zombies by having the bomber blow itself up and me shooting the bomb on the ground and not gotten the achievement. This leaves only the option of shooting a bomb while it's still on the bomber and killing 10 or more zombies (the hardest of the 3 options). It's best to do this early on so you can actually kill zombies with a single explosion. The easiest places I've found to train in early game are in the open area on the side of the command room that the mystery box is on below the staircase and out by the hole in the ground in front of the big door to the command room.

So I was following the guides in here and never got the achievement. I don't think it's glitchy, but it's tricky to make 10 zombies stay really close to a bomb on the floor so that they are killed (and don't start crawling). Gladly the game has an item that can help you: the monkey bomb. So the plan is basically the same as in other guides:

Preparation: Do this solo, it's easier and you can redo it as many times as you want. You don't need specific items beforehand but the 1911 pistol is really good and the values below are based on it. Camouflage makes it easier to shoot the bombs from the bombers (you just need to headshot the head on the back, the one linked to the body holding the bomb). Mugged is a really good talent too as it allows you to get extra jolts from the zombies when killing them with the melee attack. So this is how it goes:

0. This is ammount of shots you should take on a zombie leg before meleeing him:
wave 1 - 2 shots
wave 2 - 4 shots
wave 3 - 6 shots
wave 4 - 8 shots
wave 5 and beyond - 10+ shots
Farm the early rounds as the zombies are slower and it allows you to get the jolts without a hassle. After the first pestilence wave that is way harder so don't stress with melee after wave 4.
1. Open the village gate and light all the 3 pilot lights;
2. Clear the sewers and open the bunker;
3. Open the morgue and the lab doors and active the switchs on both sides;
4. Spend jolts on the Mystery box until you get a Monkey Bomb - If sucessfull skip to step 6;
5. If you can't get a Monkey Bomb on the Mystery Box you can either open the doors to the others Mystery Box locations or restart the game - It's really fast to get to the Mystery Box in the Bunker so I suggest you to restart the game and then repeat steps 1 - 4.
6. Open the Salt Door Mine and let the Bomber Zombies come out. Lure them to the Village and make them drop their bombs. If you have camouflage, activate it and headshot the second head.
6a. Now you should be around wave 6 or 7. The window for this to work is until the 10th wave. "Train" the zombies until you can get at least 15 of them together. Some zombies are faster than others so just take your time and kill the fast ones so you have control over the "Train".
6b. It would be smart to get a backup Weapon. There is a Weapon inside the bunker, on the opposite side of the Salt Mines Door, that has low damage and can be used. This will give you a higher chance to hit the bomb when proned.
7. When you have enough zombies close to you and to a bomb (do this by leading the "Train" on a line that has the bomb on it) throw the Monkey Bomb on the bomb. Immediatly Prone and change to your pistol. When the zombies group up, which shouldn't take long, start shooting the bomb. If you miss don't worry, your pistol have such low damage that it won't kill them. You can reload your pistol once and still have time to shoot the bomb. You can also change to your backup Weapon. If you fail, don't stress. Try again with another bomb. Above Wave 11 the zombies are stronger and the bomb blast might not kill them.

Got it on my first try with a Monkey Bomb.

Here's the way I did it - I tried the other solutions, as well as my own methods, and none of them seemed to work out. I did a solo custom game on Xbox LIVE.

Turn on power, open the vault door, route the power switches to the salt mine, and open the Sewers.

I didn't bother with the salt mine bombers, instead I opened the salt mine, killed all the zombies, then went to the Sewers and ran a train around pack a punch, with MP40 and Jack in the Box. Once at least 10 normal zombies and a bomber had spawned (I killed all Pests), I threw a Jack in one of the clear parts in the Sewer room, and before the Jack exploded, I shot the bomb WHILE the bomber zombie was still carrying it. Achievement unlocked on Wave 9.

Prior to this, I tried the exact same strategy with bombs on the ground instead of being carried by the bomber zombie, and got nothing, of course making sure to check my kill count before, and after the explosion.

TL;DR - Train zombies in the sewers, use a jack in the box once you count 10+ zombies and a bomber, then shoot the bomber.

I got the Achievement solo on wave 13.
My loadout was Frontline with Specialist Training, Fully Loaded, and Resourceful.
I only opened the first gate that leads into the town. I didn't activate any gas, open new gates, or explore. I stuck to the main, open area, bought shields as often as needed, and bought the instant revive (the green blitz) as soon as I could/had to.
I just killed wave after wave and on wave 8 the bombers started to spawn.
I tried two different methods and got the Achievement after I did the 2nd method so I'm not 100% sure which one worked.
One method I used was to shoot the bomb while it was still being carried. It was a little difficult but I was using the Type100. The idea was to activate Frontline and get as many zombies to chase you as possible, running around the sewers where the pilot light is. Once there were enough I shot the bomb.
The second method was much simpler: I just shot a bomb that had been dropped on the ground. Again I just activated Frontline with a full shield and shot the bomb as soon as I hit the ground.
The Achievement popped after I tried this method but it might have just been delayed after the 1st attempt.

To actually kill the zombies with the bomb instead of making stupid crawlers then use this character build.
1) shellshock to freeze the zombies in place while applying small damage.
2) attach the "sustain zone" mod so a area Is created near you that keeps the zombies within the train you created stunned/frozen in place.
3) the most important mod to attach is the "exploit weakness" which causes any zombies that are affected by Shellshock to take triple damage from any action including explosions.

By round 6 you should have the salt mine doors opened if you meeled for maximum points as you progressed. Lure the four bomber zombies from there back to the room you got to the salt Mines from because a tighter train space means the zombies are closer together. One you have all the zombies in the map at once then use the Shellshock once they are ALL on top of a bomb and shoot the bomb. They will be weakened to the point that the bomb kills them ALL and leaves no crawlers thanks to the effects of Shellshock and the mods.

You're welcome!