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Education / Training Beretta PX4 Storm pistol – Part 1

Beretta PX4 Storm pistol – Part 1

by B.B. Pelletier

The Beretta PX4 Storm pistol is a full-sized, semiautomatic pistol that’s now available in three calibers: 9mm, .40 S&W and .45 ACP. It’s based on a polymer frame and incorporates features like removable backstraps to tailor the pistol to the individual shooter’s hand. It’s both single- and double-action and features a high-capacity, double-stack magazine.

The airgun version of the PX4 Storm is available in .177 caliber and also shoots steel BBs. It has a 16-shot magazine that has 8-shot clips at either end. When one clip is finished you drop the mag out and flip it over for the other clip. The pistol operates on a 12-gram CO2 cartridge that provides power for the projectile as well as a realistic slide blowback.

Semiautomatic or blowback?
Blowback is a big deal because not very many pellet pistols have it. There are several with semiautomatic action, but true blowback pellet pistols are scarce. I think the Desert Eagle is the only other one. Do you know the difference between blowback and semiautomatic? A semiautomatic gun makes itself ready for the next shot by indexing or loading the next round and cocking the trigger using the power of the previous shot. A semiautomatic generally has a light trigger pull.

Blowback is when the slide of a pistol is driven backwards by the force of a shot. Blowback can cock the gun for the next shot and also index the next pellet, so a blowback is often a semiautomatic, too, but a semiautomatic pellet pistol does not need blowback to function. The Drulov DU-10 pistol and the Crosman 600 pistol are both true semiautomatics and neither one has blowback. The Crosman Nightstalker is advertised as blowback, but all that moves backwards is a small operating handle on the left side of the gun. And, the next pellet is not indexed at that time. It takes the force of the trigger to index the pellet, so the Nightstalker is technically not a semiautomatic – though that’s shaving hairs and I don’t suppose most shooters know or care about the difference.

The magazine
The magazine is really the heart of this pistol. Much of the functioning depends on the mag. It’s also more complex than other mags because it’s double-ended. There’s an 8-round circular clip at either end of the mag, so when the first 8 shots are finished, you remove the mag, flip it over and reinsert for the final 8.


Eight-shot clip is rotated by hand to load the chambers. Only one side of the mag has the pellet graphic shown, so that’s the side you load. Two projections on either side of mag are the spring-loaded ears that cause the mag to eject from the pistol when the button is pressed.

Two spring-loaded projections on the sides of the mag at both ends had me puzzled for a moment, because the owner’s manual doesn’t appear to mention them. They’re simply connected to springs that eject the mag when the mag release is pressed. You don’t have to do anything with them – the gun takes care of everything.

The circular clips are held captive in the mag. You load a pellet or BB from the correct side, then index the clip to the next empty chamber. A graphic at each end of the mag reminds you which side is correct and which way to load the pellet.

While the firearm PX-4 has an ambidextrous safety located at the top rear of the slide, this CO2 version has a separate safety located on the right side of the gun. It’s got a sawtooth central locking lever that must be slid back against spring pressure while the safety lever itself is pushed up or down. It takes force to operate and cannot be worked with just the firing hand.


Sawtoothed block is pushed back to allow safety lever to move.

The sights are a wide blade front and a notch rear. Both are cast into the slide, so there’s no adjustment. There are three dots – one in front and two in the rear – so the sight is meant to be tactical, which is suited to the pistol’s purpose. The owner’s manual shows the sight picture for shooting a target pistol, so you have the option of doing either, and that will give you two different aim points.

CO2 installation
A 12-gram CO2 cartridge is inserted in the back of the grip, once the removable backstrap has been popped off. What would be the floorplate of the magazine is actually a cammed CO2 cartridge-locking mechanism that pushes the cartridge up into the piercing pin. There’s a tensioning adjustment wheel inside that must be run up tight against the cartridge before the floorplate is swung round to cam the cartridge up. Don’t forget to put a drop of Crosman Pellgunoil on the tip of each new cartridge before you pierce it.


With the backstrap off, the powerlet is pressed into the grip. Tighten the tensioning wheel, then rotate the mag floorplate back to the closed position.

Judging by the rate at which these pistols have flown off the shelves, there are a great number of them in the hands of our readers, so please feel free to chime in with your observations.

author avatar
Tom Gaylord (B.B. Pelletier)
Tom Gaylord, also known as B.B. Pelletier, provides expert insights to airgunners all over the world on behalf of Pyramyd AIR. He has earned the title The Godfather of Airguns™ for his contributions to the industry, spending many years with AirForce Airguns and starting magazines dedicated to the sport such as Airgun Illustrated.

61 thoughts on “Beretta PX4 Storm pistol – Part 1”

  1. BB,

    With regards to Pellgunoil, do you suggest using it in the Drozd as well? I would think so, but I can’t get the fact that it’s battery operated out of my head. I have battery bias. I also love my Drozd and want it to be happy.

  2. I got one of the first PX4 Storms Pyramyd sold. Mine is fun to shoot, but accuracy is not great due to the fact the front site is not fixed to the slide, but a separate part that wiggles excessively. I have not figured out a way to keep it still. Maybe a drop of superglue? Also I tried about 10 different pellets since most caused jambs. The best I found were the Benjamin 7.9 gr and the RWS Supermag 9.3 gr.

  3. A bit off-topic but the rws 350 thread was a ways back now and I’m a new reader.. Just acquired a new RWS 350 and wondering what the currently-recommended 1-piece mount, scope (around 3-9x) and ammo is .. I’ve read back and seen good things said about Crosman Premier in a cardboard box, and that the C-mount is no good.

    I currently have an accushot medium height 1-piece w/ pin and a Tasco Golden Antler on a gamo black shadow supreme and seems to be good but I think the 350 is a much harder kicker, so…

    I did see some mention last July of a new mount pyramid was working on/evaluating.. What came of that?

  4. Marc,

    I’m still working on the new mount.

    The problem with RWS Diana guns is they shoot low. Sometimes the scope will no adjust enough for the gun, which is when adjustable mounts have to be used.

    There are many generations of RWS C-mounts. The once made in Australia and Korea don’t work well, but the current ones are made by B-Square and work fine.


  5. ok thanks for the reply – what is the best way (or is there) to determine if you have found one from B-square? Should I presume that the crosman premier and any leapers TS scope would be best in this rifle? thanks

  6. Marc,

    B-Square has been making the C-mount for several years, so if yours is new, it’s theirs.

    What caliber is your 350? That makes a big difference.

    A standard-length Leapers scope would work, as long as the objective bell has clearance over the spring cylinder.


  7. The 350 is in .22 I was looking at the this scope: /product/utg-3-9×40-ao-rifle-scope-illuminated-mil-dot-reticle-1-4-moa-1-tube?a=659

    and was kind of in the air about which mount to use. I have to revisit the question, but visually is there any way to tell if b-square made any given c-mount?

  8. Adding to the discussion of mounting a scope on a RWS:
    I was considering to buy a 34 panther in .177. I have a 3-12X44 scope that I would want to put on it. Assuming I use the proper mount, would the gun hold this scope well? And finally, would a C-mount work well with that size scope?

  9. BB – I was just curious about something. The other day I bought a Crosman Storm XT from my local discount store. The stock and sights are definitely as advertised, but at the rear of the spring cylinder it says Crosman Phantom. It doesn’t really matter, as I assume they all come out of the same Chinese factory and are nearly identical, but I was just wondering whether you’ve heard of this and if it’s common.

  10. One last thing,

    Being a fourteen year old boy, this all looks expensive.
    Is there a reason why the c-mount is so pricey? ($55)
    Is it the only mount that will compensate for how the rifle shoots low?

  11. Hi BB

    I think your last reply was for someone else (c-mount price)..

    One last question, does the standard ‘hang the pin in front of the scope rail still apply with the newest Cmounts as well?

    The idea of drilling the stop pin hole in the rail a bit deeper does sound like a viable alternative. Wonder if that rail is easily removeable?


  12. My teenage sons each have a PX4. They seem to get two full clips, or 32 shots per powerlet. Most of their use has been in cooler temperatures which may affect the number of shots.
    Their may be a few more shots in the cartridge after the second clip but it is convenient to change the co2 when one is reloading the magazine.


  13. B.B.,Regarding scopes/mounts/droop issues on Diana rifles: I have had very good results following your advice hanging stop pip over front of rail. To address droop issues on my 34/48/460/54 & a 54 I recently set up, I have simply installed a carefully cut to fit aluminum shim & placed under scope at rear of 1 pc. Accurest mount. Dont know exact thickness,(common construction alum. flashing). Have you ever shimmed a scope like this? Promise it is working fine on all my Dianas & my friends new 54. Thanks. Tim.

  14. As my last post, (really)

    When I order the 34 panther, I understand I will need the c-mount to adjust for the barrel drop. In addition to the gun and mount, (and scope that I have) is there anything else I will need to compensate for the low barrel?

    Thank you,

  15. BB, a couple of questions for you. I know these are off topic but I can’t find this info.

    First I have a Drozd which is several years old and probably out of warranty. It has stopped working. The solenoid no longer functions. Where can I get it repaired?

    Second you recently reviewed the Beeman duel caliber rifle and had a problem with the power plant giving erratic velocities. I have a Silver SS1000T Duel caliber. I chrongraphed it and got shot variations from 367.7 fps to 669.4 fps with .22 Crossman Premier HP’s. I purchased this gun about a month ago. I notified Air Gun Warehouse Inc I wished to return it for a full refund and they keep stalling me. It is now a week past the 30 day return and no rma. My first contact was at least a week before the end of the 30 day return period and I even called them at 28 days and no resolution.

    Whom should I contact to resolve this?

    Did you ever discover the cause of this? Bad spring? Leaking seals? Bad design? Could the pellets be bad? This tin looks great. No deformed skirts, bright and shiny and they look very uniform.

    Thanks for your help.

  16. Hi BB., this is unrelated, but I need to know if the pivot pin on the barrel of the 890 Gamo rife is (left handed or right handed thread, in other words do screw it in to the right to tighten or the does it tighten to the left)? Thanks Buddy

  17. Great info the PX4, but I was even happier that you advised that the Nightstalker is not true semiautomatic. I was just about to buy one – but I’m not wanting a “revolver”.

    For me, semi-auto is either locked-breach recoil or gas-operated, (FX Revolution). Blow-back does the job but, in airguns, they’ve got to let a lot of gas out to make it work. My guess, (never seeing one), is that these guns are directing some of the CO2 directly into the action – technically not recoil action, so technically only “reproduction” blow-back.

    I’d love to see a reasonably-priced semi-auto air gun that is actually accurate and powerful. Seems like only FX can make them.

  18. B.B.: Thanks for your responce. Yes I did bend the tubes on some of my “disposable” scopes in the begining. My 34 req. 2 shims & bent 2 scopes. My 54 & 460 needed only 1. Last weekend I changed my friends scope on his 54, he purshased a better one, I did not detect any deformation at all & he sold me the old Night Pro for 25 bucks! Guess I shoul get a C-mount to put my new N.P.on my 460,,Naa, Ill stick w/ what works for me— untill your new mount becomes available & Ill mount a really nice T.S. scope! Thanks B.B. Tim.

  19. pcp4me,

    That’s the problem with some dealers. They don’t back up their products. This won’t help you now but Pyramyd AIR would have taken care of this for you.

    I don’t know anyone at Airgun Warehouse Inc..

    And, yes, I had the exact same thing happen during a test I conducted for this blog, and everyone now knows about it. It’s too bad because in many ways that rifle is a good one. But the Chinese have problems with their springs.

    As for the Drozd, give the Pyramyd AIR techs a call. I think they can fix it for you.


  20. Oh Nooooo, not the dreaded ridged safety lever again! I have what looks like the same one on my Walther CP99 Compact. It does indeed take two hands to work, and it hurts my thumb to use it as well.

    Also, the gun seems to also share the same powerlet piercing system as the Walther (are they made by the same factory?) Frankly, I have little confidence in mine, and can rarely seem to get the piercing mechanism to function as it should. That’s why the CP99 Compact is the very LAST air pistol I reach for when I want to have fun shooting.

    Just my 2 cents; but buyer beware.

    -Joe B

  21. PS to above: The CP99 C IS a nice gun in many respects. I love the slide release lever on the left side…way cool. But the above problems I have with it, not to mention that I have to yank the trigger (if i release it slowly and the barrel is aiming below level, the BB drops out the end of the barrel!) to get it to fire properly, make it less than satisfactory for me. That’s why I haven’t used it in many moons. If this were a self-defence firearm and it acted this way I would be REALLY uncomfortable with it.

    -Joe B

  22. Hi BB, your note dated:

    At October 22, 2006 3:39 PM, Anonymous B.B. Pelletier said…

    None of the Leapers scopes changes impact with power adjustments. In fact, that problem has just about been erradicated by modern scopes. It had to do with placement of the elemenets inside the scope, but modern scopes are all fairly immune to it. Perhaps some very inexpensive scopes still do it, but not the good ones.


    I have a leapers 4-16 and it seems like above 7x the point of impact drops .75″. I just noticed that tonight shooting in the basement at 40′. back to 7x is on, 10x plus is 0.75 low. Groups are 1 hole at either magnification. Gun is RWS48.


  23. What is a spot weld? I tried benching on sand bags, picking a spot on the target and changing the magnification but I can’t precieve the optical change in the cross hairs on the target. I have the adjustable mount (tight) and the knobs are about in the center of the range.

  24. Mark,

    Spot-weld is the military term for locating your eye in the same place every time. You do that by locating your head in the same place.

    When your eye moves, the reticle also moves in relation to the target. That’s called parallax. The adjustable scope can eliminate a lot of it, but not all. You have to place your eye at the same place every time to eliminate it completely.


  25. For DCS;
    I have four magazines that I use in my Storm. I routinely shoot with RWS hobbys in a basement that is about 70°. By then the blowback is no longer cocking the pistol. The gun is ideal for early training for firearm recoil.

  26. Dear B.B.,
    Not to inflate your ego or anything, but “you da man!”
    Before I buy any airgun, I scan through your blogs to see what you had to say about it.
    I really enjoy your articles about how more airgun manufacturers should produce some good-quality, modest-powered plinkers.
    I had a beautiful Beeman R-7 that I got stupid and sold in my “quest for more power.” (stupid dave, he always was a dumbass =>).
    Anyway, I would like to get something like that again; I was thinking to get another R-7, but I came across your 2005 review of the Diana model 27:

    That’s some review, so now you have me thinking I should get one of those. Since they are out of production, where is the best place to find one? Also, I assume they have leather seals? If so, no big deal to make one (I saw your article on that, too).

    Keep up the good work; it is much appreciated by your readers.

    Take care & God bless,
    Robins Air Force Base
    Warner Robins, Georgia

  27. CWI,

    The two full clips or 32 shot number we came up with was based on everything working properly. After the second clip the blow back does not function properly 100% of the time and velocity seems to drop. So to revise my comments we are getting 32 consistent shots, and up to 16 erratic shots. I bet in warmer weather our numbers would be very close to yours.


  28. What a great site.

    What is the difference between a Gamo Big Cat 1200 and the Shadow Sport 1000? The only thing I could find different was the price ($99 vs. $149)

    Also, are RWS C-mounts prone to having the screw heads stripped? Either the allen wrench they supplied was wrong, or the material is super soft and junk! I have a brand new C Mount I can’t get tightened on my Big Cat.

  29. The big Cat has a plastic barrel sleeve. Other than that, not a lot of difference. Gamo just prices them differently.

    The RWS C Mounts are made by B-Square from 6061 aluminum. They are not soft. But the small screws cannot take a lot of torque. That’s why they all have locking screws. Don’t over-tighten the screws and make sure the gimbal screws are entering the divots of the hardened steel split-ring.

    I have C-Mounts that are 6 years old and have been on and off dozens of rifles and they are still tight. It’s simply a matter of using the right amount of torque.


  30. Hey! Thanks for this blog, although I bought the gun without seeing it (=

    I own Beretta PX4 Storm Air Pistol, it is a great gun, however the magazine is poor quality thus it jams the gun. I had to throw mine away. Now I’m surfing the web for the magazine. It would be great if I could find a steel one instead of plastic ones.

    Does anyone knows where I can get spare magazines?


  31. Ali,

    You have only read part 1 of the report. Go here (part 3) and there are links back to parts 2 and 1:


    Pellets are discussed, though you will see this isn’t the most accurate pellet pistol.


  32. The Storm felt very real, along with very decent recoil and realistic weight.

    The only things that somewhat bothered me about the gun was mediocre accuracy, the lack of a driftable rear sight, and the absence of a realistic and usable safety (unless you like breaking off your thumb's finger-nail by using the annoying serrated safety!).

    However, my biggest problem was the Storm's inability, at least in my case, to survive more than six or seven thousand rounds: The internal trigger linkage broke, and now the gun is a paperweight (ten days AFTER the expiration of the 3 month warranty).

  33. i brought a beretta px4 storm air pistol,,its very powerful an accurate but allready when i put a fresh co2 canister i can here it leaking is this a easy fix,would it be under a manufacters responsibility,or i am i gona have to pay for it to get repaired????

  34. First question is, are you putting a drop of Crosman Pellgunoil on the tip of the new cartridge? That is very necessary to keep the gun sealed.

    Don't try any other oil except 20-weight motor oil.

    If the gun still leaks, the dealer should replace it. Pyramyd AIR will do so.


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