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Education / Training Sig P320 pellet and BB pistol: Part 2

Sig P320 pellet and BB pistol: Part 2

by Tom Gaylord
Writing as B.B. Pelletier

by Tom Gaylord
Writing as B.B. Pelletier

Sig P320 pistol
Sig P320 pellet and BB pistol.

Part 1

This report covers:

  • Loading
  • Is there a magnet?
  • Mag feed direction
  • Velocity
  • Air Venturi Steel BBs
  • Pellets — RWS Hobbys
  • JSB Exact RS
  • Air Arms Falcon pellets
  • Yes, BB, but how fast is it?
  • The trigger
  • Evaluation

Today I test the velocity of the new Sig Sauer P320 pellet pistol. But before I get to that, I need to address loading the magazine. Some people find the 30-shot belt daunting to load because it doesn’t move easily for them. Sig sent me some additional instructions and a short video to describe the process.

Be sure to allow time for the video to upload! It might help to refresh the page.


To load the 320 magazine, the back cover is lifted up, giving you access to the pellet chambers that Sig calls “seats.” A pellet or BB is pressed into each of these, and because you are loading from the back, put the nose of each pellet in first — in the direction you want it to come out of the muzzle. BBs are spherical, so the orientation doesn’t matter. Let’s look at the video.

Notice the hand on the right that’s holding the mag seems to be pinching the sides of the magazine together. That’s not what is happening. Those fingers are actually covering up holes on either side of the top of the magazine, to keep the belt inside. It’s flexible and if it pops out one of those holes, it tends to bind and stop the movement. Covering those holes frees up the belt for easier movement.

Sig P320 pistol mag hole
I have popped the belt out the side of one of the holes in the top of the P320 magazine, to illustrate what your fingers are preventing.

Is there a magnet?

I asked Sig if there is a magnet in the belt to hold the BBs and they told me there is a magnet at the top, where the projectiles fire. I found it difficult to shake BBs out of the belt once they were loaded, but it was possible. So, have no fear of loosing BBs before the cover is closed, and after it’s closed they cannot escape.

Mag feed direction

One last thing. I noted that the belt feeds or advances counter-clockwise, when viewed from the back. I needed to know this because I wanted to test just 10 shots with each projectile, and there are places for 30 of them. So load on the right side of the belt first and it will advance up and over the top as you fire. You can even rotate the belt so the first pellet sits at the top.


Now we will look at the P320’s velocity. Sig advertises the maximum at 430 f.p.s., and since this pistol shoots both BBs and pellets, that has to be the velocity with the lightest ammunition. If that holds true, I would expect to see a lightweight lead pellet like the RWS Hobby go out at around 350-375 f.p.s. We shall see! Let’s start with BBs.

Air Venturi Steel BBs

I used Air Venturi Steel BBs for the test. Other premium BBs will give a different velocity, but it should be within 10-15 f.p.s. or so. That’s based on all the testing I have done.

In the Sig P320 pistol steel BBs averaged 379 f.p.s. they ranged from a low of 375 to a high of 385 f.p.s., so a 10 f.p.s. spread. This average is quite a bit slower than the advertised 450 f.p.s. velocity, so I will see whether lightweight lead-free pellets go any faster at the end of today’s test.

Pellets — RWS Hobbys

RWS Hobby pellets averaged 323 f.p.s. They fit the belt chambers tightly and I confirmed that each chamber has 4 thin ridges down the side to grab the pellet.

The spread with Hobbys went from a low of 305 f.p.s. to a high of 346 f.p.s. That’s 41 f.p.s. The P320 does loose velocity with every shot, so the cooling effect is at work in this pistol.

JSB Exact RS

JSB Exact RS pellets are a little heavier than Hobbys (7.33 grains, compared to 7.0 grains) but they fit the belt chambers better.I can’t call them loose because of those ridges, but they don’t take as much force to seat.

You would think this pellet would be slower than the Hobby, but it wasn’t. It averaged 366 f.p.s.for 10 shots. The low was 349 and the high was 389 f.p.s., so a 40 f.p.s., spread. I think the extra speed is because of the fit in the chambers.

Air Arms Falcon pellets

The last pellet I tried was the Air Arms Falcon dome. It weighs the same as the JSB RS, but it’s sized smaller, because they were easier to load than the JSBs. That’s probably due to a smaller skirt, because the Falcon’s head is sized at 4.52mm.

Falcons averaged 335 f.p.s., but a curious thing happened during the string. The final shot did not register, but I could tell the CO2 pressure was diminished. It was like a switch had been thrown. The range of velocities I did record ran from 309 f.p.s. on the first shot to a high of 359 on the third shot. That’s a 50 f.p.s. difference.

Clearly the gas had run out on shot 47. There were other shots taken prior to the test for different reasons. The CO2 cartridge that was in the gun is one I put in last week. So, I loaded 5 more JSB Exact RS pellets (averaged 366 f.p.s.). See how they ran.

2…………….DNR (did not register)
4…………….DNR (did not register)

The slide blew back all the way for 10 more shots, then it came back a lesser amount for the next 15 shots. But since blowback has nothing to do with the shot, I would stop after 50 shots.

Yes, BB, but how fast is it?

And now, for all those who just HAVE TO KNOW, I installed a fresh CO2 cartridge and shot 10 Sig Match Ballistic Alloy pellets. They averaged 431 f.p.s. and the spread went from 421 f.p.s. to — wait for it — 452 f.p.s. So, despite what you might have heard, Sig nailed the velocity of their P320 air pistol. And this pellet that weighs 5.25 grains is heavier than a steel BB.

The trigger

You readers were right about the trigger. It does advance the belt and is, in fact, a double action only trigger. It breaks at around 6 lbs. 9 oz. which is light for a double action pull. It sounds heavy, but only in comparison to a good single action pull.


So far the P320 is delivering everything I expected, other than the trigger. It acts like a semiautomatic, but one with a long DAO trigger like a Glock. Velocity is where it should be and the only thing left to test is the accuracy. Naturally I will do that with both BBs and pellets.

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.

54 thoughts on “Sig P320 pellet and BB pistol: Part 2”

  1. I like the belt magazine, especially in a pistol. The windows in the sides that you must cover while loading are interesting. If they do not serve any purpose, one has to ask why they are even there. Just one of those 20/20 hindsight design moments I suppose.

    Good Day all,… Chris

      • RR,

        Interesting. I figured that there would be a “cog” of sorts that would drive the main “wheel”. The 92FS I have has the circular clips that are driven by a finger that engages some “teeth” on the clip. Much like ratchet.

        • Chris same on the 1077 and Wildfire. Also the Colt Python and Brodax.

          Pretty common on quote “semi-auto” Co2 pistols. And revolvers.

          The semi-auto guns need some way to advance the clip. They don’t have the gun powder percussion to cycle the action.

            • RR
              The semi-auto Monsoons I had don’t cycle the same as what guns I mentioned.

              And the Evonix are battery operated​. I know I had one too.

              But anyway cool that they are making these type of semi-auto guns.

                • RR
                  I need to see if I can find the schematics. Like to see how they are doing it now.

                  Don’t think I’ll be getting one soon. But if they end up making a PCP that can fire semi-auto​ for 9 shots I just might change my mind.

                  Well if it’s accurate that is.

                  • GF1,

                    LOL! You don’t want much do you? I don’t know what you consider accurate, but there are not many production air rifles in .45 that I consider accurate, no matter what type of action. Although now that JSB is making a pellet in that caliber, it may not be too far off. I consider 1 MOA or better accurate.

                    The Evanix is going to be offered in .177 and .22. It may be offered in .25, but I am not sure. They are also going to be offering it in side lever.

                    • RR
                      Haha I know.

                      And you know I been thinking about this too. Well first off to say I’m on a Co2 kick here lately. But I wonder if one of the 20 oz. paintball Co2 bottles could power a gas operated PCP gun instead of hpa. And know you know what I mean by saying gas operated. I should say air operated and not a mechanical trigger operation.

                      If it could fire a .177 pellet and get a fair shot count I think that would be a cool gun to have.

  2. It sounds like the belt fed design is always going to require a dao trigger. Why couldn’t stick mags, or the mag like is in my Umarex Colt Commander be designed to feed pellets? I would rather have a more realistic trigger pull than high capacity.

  3. Good morning B.B./anyone,

    Here’s an interesting question…

    Do you think it might ever be possible to make a big bore Colt SAA airgun in .45 or .357 caliber? Perhaps with dedicated, and therefore light weight, non-lead bullets.


    Joe on Maui

    ps. Still waiting for that .22 caliber Umarex Colt SAA with 4 and 3/4″ barrel. :^>

  4. I feel that there are only two reasons people buy guns like the SIG P320. First is the person who desires a particular gun and can’t own it for what ever reason, be it age, lawful restrictions, or whatever. Second is the person who wishes to practice various shooting drills, as well as handling techniques which requires a very close copy or clone of a specific firearm. The SIG P320 misses this mark on more than a few points such as non working controls,a magazine design that doesn’t allow for tacticle reload practice, non adjustable sights on a rifled pellet pistol, trigger pull, even the shot count could be seen as a liability for practice . I personally would be willing to pony up more for more realistic features.

    • My thoughts as well. In fact, a person who uses the P320 airgun will be misled into thinking he knows the real P320 as well. He might be surprised to find that he had to rack the slide on the real P320 to get a round into the chamber.

      • The airgun is very similar in size to the real P320. The magazine release on the airgun is similar in position to the real gun. Most importantly the sight picture is very similar. I can leave the unloaded airgun around and pick it up to acquire a target whenever I like.

        The similarities, and my very favorable view of Sig Sauer, are why I spent more money to get the P320 airgun. It is good practice for the real thing. It saves trips to the range and money on ammo even using the alloy Sig pellets.

        Anyone who buys an airgun and thinks they know how to handle a real firearm is not long for this world.

    • Sal
      To give some realism or should I say similarity to the firearm recoil.

      I have one of these.

      The reason I got it was for fast action shooting. And basically I want to feel the gun bump when I shoot. And with your question it gives the person shooting the gun that feel and is a way that the gun can still seem to the shooter it’s semi-auto and have the recoil of the blow back.

      • GF1,

        I see that HAM did a head to head match of the Benjamin Maximus and the Beeman Chief. Pretty equal, but I think the Maximus edged out a win. For me, the lighter weight, new barrel and plain good looks,.. the Maximus would still be my choice. Not to mention,… parts availability. Just an FYI for anyone pondering a (near future) choice between the two.

        • Chris U
          I saw the head to head. You know me. I can’t say one way or the other until I get the opportunity to have each one in my hand and spend some time with each.

          And I heard something today. Crosman supposedly got bought by someone. And don’t know if that’s a good thing or a bad thing yet. Supposedly the person involved was a owner in Crosman in some way.

          But that’s the first thing that came to my mind when I heard about Crosman today. Hope they will still have digrams and parts available to the general public.

          And as far as the Chief. There is probably as much aftermarket​ parts for them as there is for the Crosman guns. Plus I know a few places that I won’t mention here that have factory replacement oars for them.

          So with that said. We’ll just have to see how it goes.

          • GF1

            “oars”,…. ? How many extra FPS you gonna’ get with oars? How would that even work? 😉 I am not familiar with the Beeman brand,.. but that is good that parts will not seem to be an issue. Interesting news on Crosman. Yes,.. I do hope that parts availability do not change. Do not mess with a good thing.

            • Chris U
              I know I saw it but didn’t have time to post then to correct myself.

              Suppose to say parts. Thought you could decifer that stuff by now after reading my replys for 3 years. 😉

              And yep if they cut off parts supply to the general public in my eyes that will be a disaster on their part. Bad consquenses would follow I’m sure.

              And yep I messed with some of the QB guns. But that was before Beeman started putting their name on them.

            • Chris USA,

              Given that the Chief has been produced since 1955, the Maximus will be long off the market before it’s parts availability is equal to that of the Chief right now.



                • Yes a lot more, takes some time to look it up but the bottom line is we will not know how it will change Crosman till the changes happen.

                  Compass is all about making the money, I just hope it works for them and Crosman, more importantly the Crosman employees.

                  • Mike
                    Some of the articles I seen showed workers assembling 760’s.

                    Hope it does work out for the good.

                    First Daisy by Gamo. And now Crosman. At least this person has worked for Crosman. But whatever that might mean. Like you say we will have to see what the change means.

                    But you know people will be watching now. If they make changes and people don’t accept. Then the sale was useless for profit. It didn’t gain anything for anybody then.

                    • Gunfun1,

                      I had a great uncle and two cousins who worked at Sheridan. That would be when Sheridan was Sheridan, as in Racine, WI and pre-Benjamin.


                  • Mike,

                    “Compass is all about making the money.”

                    Well, there is nothing wrong with making money, but your comment about them makes me think if there is any Crosman product I wish to someday [purchase, perhaps I ought to do so sooner rather than later.


                    • Crosman makes money so as long as that continues I do not see Compass changing things. But you never know.

                    • Michael
                      I like to hear when people do something with their guns. Sometimes it don’t seem right to me when they comment. But then when I think about it. It does make more sense the more I think about it.

                      But about your comment about buying a Crosman product now more than later. Well in this case I hope your totally wrong.

                      That will be a crying shame if they ruin what Crosman is today.

                      But on the other hand maybe they will drop all those silly Chinese break barrels they make. Sorry but to me they are useless guns. Yes that’s right boat oars. 😉

                  • Mike,

                    My concern would not so much be in terms of quality of product but in terms of lesser-performing (in sales and/or profit margin) products being dropped from the line.

                    My prediction is that boxed Premiers, which must provide tiny margin as they are hand sorted, will be the first product dropped, the proverbial canary in a coal mine. You read it here first.


                  • B.B., Mike in Atl, Chris USA, and Gunfun1,

                    Space about Compass acquiring Crosman was getting scarce above, so I posted the following down here.

                    Crosman Premier .22 in the box have already been discontinued:


                    And it seems only remaining retailer stock of Premier .177 in the box are available, as the two largest air gun online retailers are out of them presently. Also, if you own a Sheridan and like the Benjamin .20 cylindrical pellets, I’ll act soon. For all anyone knows the last-ever batch of those has been shipped to retailers, P.A. and A.D.

                    It is quite possible Crosman dropped those from the official (i.e. “The Books”) product line because they are very low margin. This has the effect of making their literal margin bottom line more delicious to a potential bigger fish when that bigger fish looks over their accounts. It’s a corporate way of putting on make-up before the date, so to speak.



                    • Follow-up — go to crosman.com, then to “Ammo,” then search for Premiers and try to find them in any caliber in the box. .177 has been taken off of their search engine, so it has been discontinued. Benjamin Cylindrical .20 are still officially available using that ol’ detective trick.


                    • Michael
                      I was going to comment about that.

                      One of the articles I read about this recent buy out mentioned they made 6 million pellets a day. Yes a day.

                      Here’s the link.

                      So maybe certian pellets that have not been selling needed to go. You know the Premieres​ in the box use to be the feild target pellet the shooters bought by the “lot”.

                      Well now the pellet that a lot of the feild target shooters use is the Air Arms or JSB 10.34’s.

  5. B.B.,

    So the P320 air pistol is really a revolver (but not a Colt, given the counter-clockwise rotation ;^). Considering the iffiness of most multi-shot pellet actions that are not really revolvers, that is probably a good thing!


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