by Tom Gaylord
Writing as B.B. Pelletier

Umarex Legends MP40 BB submachinegun.

Part 1
Part 2

This report covers:

  • Other interests
  • Hornady Black Diamond BBs
  • Semiauto?
  • Umarex Steel BBs
  • Full auto
  • Back to Hornadys
  • How many BBs?
  • Shot count
  • Summary

Today is accuracy day for the new Umarex Legends MP40 BB Submachinegun. I’ve read reviews that say it is surprisingly accurate, so I was hopeful.

Other interests

Besides velocity, you readers had several other things you wanted me to try. I tried a few and will also report those results. Let’s go!

Hornady Black Diamond BBs

First up were Hornady Black Diamond BBs. I loaded just 10 into the magazine, because I wanted to shoot a 10-shot group. The MP40 stops shooting after the last BB is fired, so there is no risk of dry-firing and wasting CO2. The gun already had two mostly fresh cartridges in the mag from the end of the last test, so I went with those until they were exhausted.

I shot from 5 meters, using the UTG Monopod as a rest. The stock was extended and I have to say, the sight picture is very clear and sharp. It reminds me of a 9mm H&K MP5 I once shot — very easy to aim.


When the first BB fired I was surprised because it felt like a short burst instead of a single shot. The gun vibrated like many shots were firing. I actually walked to the target to make sure there was only one hole it it, and there was. Also, I counted the next 9 shots and after they were gone I pulled the trigger one more time. Nothing happened, as it shouldn’t. So, semiauto feels like full auto. That is a real plus!

The first round hit the target below the bull. I aimed at the 6 o’clock spot and I would say the BB hit about 1-3/4-inches lower.

After 10 shots were fired I looked at the target and was pleasantly surprised to see a tight little group. It’s in line with the center of the bull and measures 0.525-inches between centers. That is one of the smallest 10-shot BB groups I’ve ever shot with any gun except a Champion 499.

MP40 Hornady target semi
Ten Hornady Black Diamond BBs went into 0.525-inches at 5 meters when the MP40 was fired semiauto.

Umarex Steel BBs

Next up were 10 Umarex Precision steel BBs. I raised the rear sight leaf that gives a little elevation for this group. It moved the strike of the rounds up about one inch at 5 meters, but as you will see, it’s still a little low. Ten BBs landed in 1.012-inches at 5 meters. If I hadn’t shot the Black Diamond group first, this would be one to shout about.

MP40 Umarex target semi
Ten Umarex Precision steel BBs went into 1.012-inches at 5 meters.

Now we know the MP40 is very accurate. What’s next? Well, there was some talk about how large the groups would get when we fired all shots full auto, so let’s try that. I loaded 10 Umarex BBs and set the selector switch to full auto. Time to rock and roll!

Full auto

Ten Umarex BBs fired full-auto went into 1.128-inches at 5 meters. As you can see, they landed in the same place as when the gun was fired semiauto. Considering the way the gun bounces around, that’s pretty darn good!

MP40 Umarex target full
Ten Umarex BBs on full-auto made this 1.128-inch group at 5 meters. Not too shabby!

Back to Hornadys

I thought Hornady Black Diamond BBs might do even better, since they did in semiauto, so I loaded 10 into the mag and attacked another target. This time the gun got away from me and I knew it as I shot. Ten Black Diamond BBs landed in 2.85-inches at 15 meters. This was all on me! You have to hold those subguns tight if you want them to shoot.

MP40 Hornady target full
Yep! The MP40 got away from me. Ten Black Diamond BBs in 2.85-inches at 5 meters.

How many BBs?

Another question we had last time was how many BBs could be loaded into the magazine. And I discovered something. I thought people were saying the magazine would jam if the mag was overloaded, but they weren’t! They were just saying the mag would not accept 60 BBs. That’s all. No jamming. I misunderstood.

I discovered this when I tried to load 60 BBs into the mag. Remember that picture in Part 2 where I showed all the BBs stacked in a neat double stack? What I didn’t tell you was it took me several minutes of fiddling with the follower to get even that few BBs to organize correctly. Sometimes they just want to leave a hole for a BB, and there is no easy way to get a BB into that place. If you pull the follower down again you may fill that gap, but you will create two others somewhere else.

I was able to get somewhere between 52 and 55 Black Diamond BBs into the mag. It’s next to impossible to say how many there were for certain, but it was more than 50 and less than 60. When I fired in three long bursts, all the BBs came out as they should. Man was that fun! So, it’s the mag that has trouble filling all the way. That’s a relief!

Because of that I found it unnecessary to try Crosman BBs or to oil the mag slot, like some readers suggested. Whatever I could put into the mag shot out without a problem.

Shot count

Which brings me to the shot count I reported so dutifully in Part 2. I said 70 full-power shots were possible, but in this test I started with 10 on the CO2 cartridges already, and I shot a minimum of 90 more today. That’s 100 shots and the gas was still holding. So I reloaded a mag of Umarex BBs — 50+ more, and fired again. All 50 fired with power. That’s 150. Then I shot about 15 more before the gun ran out of gas. Let’s call it 160 shots to be safe. That’s a lot more than I shot last time.


I am still impressed by this BB gun. It is proving to be more fun than I anticipated — and I don’t like full-auto guns!