The BB Conundrum Part 2

The BB Conundrum Part 2 Part 1

Smart Shot, lead, steel and dust

By Dennis Adler

The best all around choice for a CO2-powered, blowback action air pistol, the Umarex S&W M&P40 proved to function flawlessly on Smart Shot copper plated lead BBs. These make the training experience that much better since Smart Shot can be used on reactive metal targets.

The number one choice in blowback action CO2 pistols for training with a reactive or metal target has to be the Umarex S&W M&P40. So this is where we begin the search for a blowback action pistol with a self-contained CO2 BB magazine that will function correctly with Smart Shot. For whatever reason, the copper plated lead rounds, although heavier than steel BBs, get driven down into the magazine channel when the pistol fires. This compresses the follower spring and can force one round out of the loading port and jam the magazine. If there is no loading port nothing happens, and the Smart Shot functions perfectly. In semi-auto designs where jamming happens, it becomes continual making it impossible to use Smart Shot. But do all blowback action (or non-blowback action) semi-autos with self-contained CO2 BB magazines have loading ports that allow this to occur? The answer is not all, and the first and best example is the M&P40 which has one of the smallest loading ports and heaviest follower springs of any self-contained CO2 BB magazine.

Why does Smart Shot work in the M&P’s self-contained CO2 BB magazine? The staggered column M&P mags are notoriously hard to load because they have a heavy follower spring, a small follower and very small loading port; exactly the recipe for loading Smart Shot. The follower spring is too strong to allow the BBs to be pushed down very far (if at all) when the gun is fired and even if the bottom one or two get even with the loading port, it is too tight for the BB to push out and jam the follower.

Loading steel BBs into the M&P40 magazines, as everyone who has one knows, is hard. The follower tab is almost flush with the magazine, it is small and the follower spring is heavy. Compounding this is a loading port half way down the follower spring channel that is barely the size of a .177 caliber steel BB. This may be good news if you want to shoot Smart Shot and use the M&P40 for training with reactive or metal targets.

The M&P40 functioned without any hiccups in the action and maintained an average velocity of 258 fps with the heavier copper plated lead Smart Shot, compared to steel BBs, which average 302 fps. You sacrifice about 40 to 50 fps to gain the ability of shooting with reactive metal targets.

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The M&P40 CO2 BB magazines are the air pistol equivalent of a double stack in that the BBs stagger rather than being in a solid vertical column. The M&P40 holds 15 rounds. The heavier 7.4 gr. copper coated lead BBs averaged 258 fps from the M&P40 which sends steel BBs downrange at an average of 302 fps, so again about a 50 fps reduction in velocity compared to the lighter 5.1 gr. Umarex Precision steel BBs. With the Umarex HK USP the difference between steel and Smart Shot was 64 fps but the non-blowback USP was still sending the heavier lead rounds into the target at an average of 352 fps. The blowback action M&P40 doesn’t have that much power to spare, but is still pretty snappy with Smart Shot, and due to the irritatingly small loading port and heavy follower spring there is no issues with Smart Shot backing out and jamming the gun. The M&P40 is Smart Shot ready for the reactive target test range.

There is a third option with the M&P40 which also works flawlessly with frangible Dust Devils molded composite BBs. Again there were no malfunctions and the M&P40 picked up 62 fps with the light weight 4.35 gr. Dust Devils, for an average of 320 fps.

The second round is the M&P40 with Dust Devils for a run at maximum velocity. The Dust Devils are cast and as previously noted have a small ring around their circumference (like a single ring around Saturn), and that may or may not affect the operation of the M&P40 magazine. With a fresh CO2 cartridge in the M&P40 magazine the 4.35 gr. Dust Devils clocked an average of 320 fps. Not as significant an increase as with some of the other air pistols tested, but 315 fps plus with the frangible rounds makes them ideal for training on hard targets with the M&P40. Next up; the popular Sig Sauer P226 X-Five.

The same test performed with the Sig Sauer P226 X-Five had even better results with the Sig maintaining an average velocity of 281 fps with the Smart Shot and 340 fps with Dust Devils.

Internally, the Sig shares much in common with the M&P40 CO2 model and uses a similarly designed magazine; however, the Sig’s does not have a loading “port” per se, but rather a locking follower with a wider channel above it that allows loading BBs when the follower is pulled down just a fraction below the catch. Like the small loading port on the M&P40 mags it is unlikely a Smart Shot BB will back out and jam the follower. This magazine also has a comparatively strong follower spring.  The Sig is a pretty powerful CO2 pistol and the heavier Smart Shot does not fall too far below 300 fps maintaining an average velocity of 281 fps. Again, no issues with jamming or blowback operation using Smart shot in the Sig.

Like the M&P40 the Sig has a staggered column, heavy follower spring and a small loading port. This combination worked with both blowback action CO2 pistols. The same results were achieved with Dust Devils, which delivered the highest average velocity.

Switching to Dust Devils, velocity from the full size P226 X-Five was an impressive 340 fps average, no issues with feeding or the blowback action. So here again you have two viable non-steel options for use with reactive targets and Sig even markets their own targets (which we will get into later this spring).

The Swiss Arms P92 (Beretta 92FS design) is a natural for the Smart Shot as it has a fairly heavy follower spring and no loading port at all; BBs are inserted into the firing port. The Smart Shot ran perfectly. The Dust Devils also delivered excellent performance but caused two failures to fire (slide locked back like an empty magazine) which was corrected by removing and reinserting the magazine and dropping the slide.

Finally, a blowback action pistol with a self-contained CO2 BB magazine that can’t fail with Smart Shot because it has no loading port; the Swiss Arms P92 (Beretta 92FS design), which loads BBs directly through the firing port. This is also a staggered column magazine so capacity is a copious 21 rounds. The P92 is another full-sized duty gun that is rated with .177 caliber steel BBs at 312 fps. Dropping 21 Smart Shot copper coated lead rounds into the magazine returned an average velocity of 271 fps. Once again we see about a 30 fps average loss in velocity but capability to shoot with reactive metal targets as the tradeoff. Switching to Dust Devils the Swiss Arms slammed the lightweight rounds into the target at 330 fps so there is a noticeable gain in velocity once again.


The culprit with either of these two non-steel rounds is that they are “magazine specific.” Not so much the airgun design, but rather how the BBs load, the size and placement of the loading port, and the resistance of the follower spring. The larger the port, the easier BBs are to load and the easier it is for Smart Shot to cause a jam, doesn’t matter if it is a stick magazine or a self-contained CO2 BB magazine. A heavier follower spring also helps minimize the problem. A magazine with a large loading port and low resistance follower spring is a Smart Shot non starter.

What works and what doesn’t? At left, the self-contained CO2 BB magazine from the Umarex HK P30, at right the magazine from the Umarex S&W M&P40. Notice the size of the loading ports (red arrows), the large beveled port on the HK P30 makes it easy to load. This can (and does) allow one Smart Shot round to push out of the port and jam the follower, stopping the gun from firing. The second and equally important detail is the size and strength of the follower springs. The P30 has a smaller sized spring that does not apply significant pressure on the follower. Again, this is easy to load, but problematic when using Smart Shot instead of steel BBs. This same style magazine is used in a number of CO2 pistols and most will have the same issues with Smart Shot. The follower spring on the M&P40 magazine, as well as the Sig and Swiss Arms mags, is heavier and more tightly wound. It has almost twice as much resistance as the HK magazine when loading.

As this review has shown, there are plenty of top notch blowback action CO2 pistols that perform well with Smart Shot. Now how about the new Dust Devils? Again we have seen no failures with operation, the molded composite rounds stand up to follower spring tension even in staggered column magazines, (if they broke down under pressure they would not have been able to chronograph consistently), so here we have the best of both worlds, a higher velocity frangible BB that can be used for shooting with metal targets and metal pellet traps and the lowest possibility of ricocheting since the Dust Devils literally turn to dust on impact with a hard surface.

Dust to dust. At right unfired Dust Devils, at left traces of particles found at the base of the target stand where Dust Devils disintegrated on impact with heavy cardboard target backers. They do, nevertheless leave an imprint on Shoot-N-C targets, as well as dimple the cardboard and have enough velocity to move a reactive metal target before disintegrating into small fragments you can sweep up with a whiskbroom. No ricochets here. (Notice the small ring around the center of the Dust Devil BBs. This is part of their construction).

Even with the heavy cardboard front panel on my baffle box, which is always penetrated by steel BBs, pellets, and even Smart Shot, a good majority disintegrated against the cardboard surface (unless hitting a spot already split by previous hits) and deposited a layer of grey particles on the floor in front of the target stand. Dust Devils will be the reactive target BB of choice for BB revolvers, blowback and non-blowback semi-autos…if they prove accurate.

In the Part 3 conclusion all of the models tested go for accuracy at 21 feet with Smart Shot vs. Dust Devils.

5 thoughts on “The BB Conundrum Part 2”

  1. Since misdeeds are mentioned today please excuse my off topic question.
    A new Swiss Arms 1911 jams very often, usually with smart shots but not only. Tried also a magazine with shortened spring, no cure. Any help would be welcomed.

    • If it’s getting jammed by the slide getting stuck or not going all the way forward, this has happened to both of my Swiss Arms 1911. I fixed it by using moly grease on the frame and also a some moly grease on the small spring under the black plastic near the back and underneath of the slide. I don’t know what this part is called but the sprIng being dry will cause the slide to not go fully forward after firing a shot and hence jam. This was the case with both my pistols right out of the box and a third one for a friend.

  2. I’m looking forward to the accuracy test next article as it probably pertains to my question. Does the loss of 40-50fps have any notable effect on trajectory when shooting from 21feet? I know this is the territory of ballistics but at the short range involved is this even a factor with a fresh c02? Likewise would the slightly higher FPS of the dust devils change the POI at short distances.

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