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CO2 Sig Sauer P320 M17 CO2 pellet pistol: Part 3

Sig Sauer P320 M17 CO2 pellet pistol: Part 3

by Tom Gaylord
Writing as B.B. Pelletier

Sig M17 pellet pistol
Sig Sauer P320 M17 pellet pistol.

Part 1
Part 2

This report covers:

  • Correction
  • Sig wonders why we want to disassemble the gun
  • The test
  • Sig Match Ballistic Alloy
  • Rifled barrel
  • Magazine gas loss
  • Air Arms Falcon pellets
  • Crux Ballistic Alloy
  • Blowback
  • Trigger pull
  • BBs
  • Daisy BBs
  • Smart Shot a no go
  • Beeman Perfect Rounds
  • Shot count
  • Discussion
  • Summary

Today we look at the velocity of the Sig P320 M17 pellet pistol. But there will be more to this test than just three pellets. Because readers wondered if it could also shoot BBs and I learned that it can, I will test them, as well. As long as I’m testing BBs, I will test lead balls of differing sizes, because when we get to the accuracy test I’ll want to test them as well.


I told you in the last part that the magazine cap has to be removed to insert a CO2 cartridge. That was incorrect. Just remove the mag from the gun and insert the cartridge by following the directions in the manual. Leave the cap alone.

Sig wonders why we want to disassemble the gun

Sig asked me why anyone would want to disassemble the gun for any reason other than clearing a jam. I explained that, like airsoft, these lookalike pellet and BB guns are attractive to shooters who cannot own the firearms they represent. For shooters in places like California, New Jersey, Illinois and New York, the gun laws are very restrictive. It might be impossible to own an M17 firearm in those states because it has a magazine that holds more than 10 rounds. A pellet gun might be as close as they can come. I think this view is one that a company gets as they continue in the lookalike field. I remember when I asked Wulff Pflaumer, the owner of Umarex, to make a single action revolver that looked like it had been well-used — he was amazed that anyone would want such a thing. But twenty  years later Umarex can’t keep up with the demand for guns that have the “battlefield finish.”

The test

Okay, let’s start testing. I will shoot 10 shots with each type of projectile and record the results. Because this pistol if powered by CO2 I will wait at least 10 seconds between shots, unless I say otherwise. That keeps the gun from getting too chilled and affecting the velocity.

Sig Match Ballistic Alloy

First up were Sig Match Ballistic Alloy target pellets. They averaged 368 f.p.s. over the chronograph. The spread went from a low of 359 f.p.s. to a high of 387 f.p.s. That’s a spread of 28 f.p.s.

Rifled barrel

A couple readers asked whether the M17 has a rifled barrel. Yes, it does. Dani Navickas of Sig sent us a great photo of that.

M17 barrel
Yes, the M17 barrel is rifled.

M17 pellet
The rifling only touched the pellet lightly at both the head and the skirt.

Magazine gas loss

Each time the magazines is removed from the pistol there is some loss of gas. The magazine pops out of the gun because of its internal gas pressure and you can hear a small pop, which is the gas escaping. Because of that, I loaded 20 pellets or BBs into the magazine each time it was out of the gun to minimize the number of times the magazines had to be removed.

It was easy to index the magazine belt so there were 10 of the same projectile to be tested. When you look at the back of the mag the belt climbs on the right side, so just set it so the last pellet that you don’t want to chrono is in the window at the top and when you pull the trigger the next pellet, which is the first one of your string of 10, will move into position. After those, of course, the next 10 will be the next pellets or BBs to test. And after that it’s time to remove the mag and reload.

Air Arms Falcon pellets

Next to be tested were 10 Air Arms Falcon pellets. These are lightweight lead domes. They averaged 319 f.p.s. with a 37 f.p.s. spread, from 295 to 332 f.p.s.

Crux Ballistic Alloy

Next up were some Sig Crux Ballistic Alloy domes that are made from pure tin, like the Match Ballistic Alloy pellets. This is a pellet I haven’t tested yet. This is the first time I have tried them.

They averaged 359 f.p.s. in the M17, with a 31 f.p.s. spread that went from 347 to 378 f.p.s. If you look at the specs you will see that the Crux weighs a little more than the Match pellet, so a slight velocity drop is to be expected, I guess.


The M17 has full slide blowback, so the feeling of recoil is realistic. And the gun doesn’t use the slide to cock the hammer or to advance the pellet in the magazine, so it isn’t using as much gas as some guns do.

Trigger pull

I measured the double action only trigger pull at 6 lbs. 4 oz., which is very light for a double action pull. The trigger stacks (increases in pull weight) at the end of the pull, so you can control the pistol quite well.


Now let’s test some different projectiles — starting with a steel BB. I chose Daisy BBs for this test. They load into the magazine well and do not fall out when the mag is turned over, so there must be magnets in the plastic chambers of the belt.

Sig M17 mag
Looking at the back of the magazine with the loading door open, the belt moves counter-clockwise.

Daisy BBs

Daisy BBs averaged 331 f.p.s. for 10 shots. The range was 36 f.p.s., going from 321 to 357 f.p.s. I think these BBs are so small for the bore than gas passes them and they lose velocity. Let’s try something else.

Smart Shot a no go

I tried H&N Smart Shot next but they were not retained by the magazine. When I tipped it over they fell out and I didn’t want to jam the gun, so I didn’t shoot them . However, there might be a solution.

Beeman Perfect Rounds

Beeman Perfect Rounds are a true .177 caliber and they fit snugly into the chambers in the belt. Nothing fell out when I turned the magazine over. They averaged 252 f.p.s. in the M17. That’s slow, but these balls weigh more than 8 grains.

Perfect Rounds are no longer offered, but Gamo Round Lead Balls should be essentially the same. I don’t know why anyone would want to shoot them in this pistol unless they are incredibly accurate, but they do work.

Shot count

At this point in the test the gun has been fired 51 times on the same CO2 cartridge. So I loaded a magazine of Sig Ballistic Match pellets to see what the remaining velocity might be. Instead of an average, I will show the entire string.

Once I saw what the first round did, I decided to shoot as fast as I could and still record the numbers. That put 5-8 seconds between each shot.



Looking at these numbers I feel the gas ran out somewhere around shot number 12 on this string. That would be a total of 63 shots on a cartridge. But I continued to shoot, just to see if that was right. I was certain the gas was gone, so I loaded 5 more of the same Match Ballistic Alloy pellet and recorded the velocity. This time I allowed a minute to pass between each shot, to give the gas every chance.

2……………..241 gun got very quiet from here on

As you can see, the gas has run out. But because of how the gun is designed the slide is still blowing back with every shot.


Okay, now we have a good idea of how various projectiles perform in this pistol. I guess all that’s left is the test it for accuracy. Yippie!

42 thoughts on “Sig Sauer P320 M17 CO2 pellet pistol: Part 3”

  1. Good morning to you all.
    It is surprising to realize the possibility of executives working for such a great gun company don’t know about the restrictions existing. Not so promising for the future of arms generally, but for understanding the needs of their clients also.
    P.S. Is it really necessary to have the presentation of the topics since it takes so much space? We all enjoy your thoughts and need as much as you can offer.
    Best regards

    • Bill,

      LOL! Here we go again! This has been discussed back when. The table of contents was added because there are those who like to know what’s coming.

      Don’t sweat it. Space is not an issue. Volume (think number of words) is where any restriction may arise. Just do like I do and scroll on by. Skip the appetizer and go straight for the entrée.

      • B.B.,

        I almost always look to the Table of Contents first. I often will then skip to one or two sections that pique my interest the most, and then start over and read the whole thing.

        I, for one, have come to find it quite useful.


    • Hi Arcadian,
      Welcome. =>
      Sadly, it’s not just gun companies that are this way.
      Judging by the companies for which I have worked, I think some execs may get to be execs
      because other guys who are already execs look at them and say,
      “Hey, that guy has an Ivory Tower mentality just like me; let’s promote him to be an exec, too. Yippie!”
      Don’t get me wrong.
      Some execs are awesome and in touch. According to workers on the floor to whom I have spoken,
      Chuck Buck, CEO of Buck knives is “the real deal;” he walks the production floor with NO entourage,
      and talks to EVERYONE. He listens to people, hears their concerns, and keeps up on where his
      company should be going.
      It would be nice if more execs followed his lead; but then again, his company also made
      God their Senior Partner, so I guess their success should come as no surprise. =>
      take care,

  2. BB
    I don’t want it to sound like I’m putting the gun down because it seems like it’s efficient, especially nice that the blow back keeps operating at low Co2 pressure and respectable trigger response and pull weight and that it does shoot pellets. And I really like all that.

    But “you” know what’s next. Accuracy.

    This is a training gun so to speak. What’s bothering me is Sig didn’t go one step farther and offer adjustable sights. At least for windage anyway. I don’t mind compensating on my elevation holds but still would like to be able to adjust windage as well as elevation.

    If Sig is aware. To me that’s something that shouldn’t of been overlooked.

    And I want to end my comment on a positive note. The pistol is nice to look at the lines as well as the color. And again. It shoots pellets.

    I just hope the sights and gun are good enough to hit a tin can at reasonable distances. If it can do that. Then I believe it stands a chance as a trainer. Or I guess I should say. A practice gun.

      • BB
        I didn’t know if the firearm version had adjustable sights. You never mentioned. I was going to search it and see.

        So did they qualify the firearm version? What I mean is do they build the pistol to hit in a certain area by aim point? Or do they leave it to the shooter to figure out the sights for that particular gun.

        I’m sure most will figure that out if they shoot enough. But adjustable is the way to go in my opinion for the nice package they put together.

        I would think that Sig would of went one step beyond if you know what I mean.

          • BB
            That’s nice they do the same.

            I’m waiting to see how it does when you shoot it.

            I really would like anoher nice action pistol. My oldest daughter likes the pellet shooting Python we have. She’s actually pretty good with it. But also it happens to be pretty accurate for a bargain priced gun.

            I have to ask this though. You mentioned the gun discharges some Co2 when a clip is released. But it seems like it’s not much.

            What I would like to know is how many usable shots does it get out of a cartridge. Or am I jumping the gun. Maybe that will also be answered when you shoot the group test.

            But for sure interested too see what happens.

            • GF1,

              One of the things that makes that Python so much fun to shoot is those excellent adjustable sights that bit sports. The same FULLY adjustable sights that are on the even CHEAPER BB version of the gun. I agree with you, the airguns of this action shooting ilk should at least have a driftable rear sight. Most all of mine shoot low left or low right and I just don’t see why it would have to be that expensive to correct. My two cents.


    • Gunfun1,

      I’ve got the M17 pellet pistol. It actually shoots reasonably well with just a little holdover for me.

      I’ve also got the Sig X-Five pellet pistol which does have the fully adjustable rear sight. The adjustable rear sight on the X-Five pellet pistol really didn’t help me very much.

      • Cstoehr
        From what you said that makes me think the guns and sights are made pretty consistent.

        But still I’ll take adjustability over none adjustable. Everyone shoots a little different and being able to fine adjust the gun in makes all the difference in the world.

        And I guess I should ask what distances were you shooting at?

        • Gunfun1,

          With pistols I start at 18 feet, even with pellet pistols. I want to see how wide the shots will go at a short distance first before moving back to 10 meters with a pellet pistol lest at 10 meters I completely miss the pellet trap because the shots are going far to the right or left.

  3. I just recieved a Beeman P17 from PA. I really liked my Marksman 2004, but gave it to my son. The P17 has fiber optic sights yuk. I removed the fiber optics and with some JB weld and a file was able to get the target sights back. I filled the holes on the rear sight and made the front sight back into a square post. One new good thing is both the windage and elevation screws on the P17 rear sight now have detents.

    The first thing I did was check the compression cylinder for burrs this one looked like there was better quality control on the cylinder than was typical years ago. It was smooth with no sharp edges especially around the air intake hole. So far so good.

    I hope it is as accurate as has been typical over the years.


  4. FYI, for the airgun community,

    I was saddened to see that Kenny Kormendy had passed away on Aug 30. Kenny was another great airgun reviewer and gave very honest reviews of many airguns. His video reviews are being kept online by his daughter. Here is the link to his YouTube channel: https://www.youtube.com/user/myairgunreviews/airgun-videos

    Kenny had been battling cancer for the past year and even though he has left this world to be with his heavenly father, his work will live on though these videos.

    • Geo,

      I have caught a few of his. The one thing that stands out in memory is that he was (super) down to earth. I wish I had more time to keep up on all of the good stuff (videos) out there. Daystate had a big get-together in Arizona? recently and was providing regular video updates and it was surprising to see many of the usual You-Tube reviewers were out there covering the event. Quite refreshing and I wish them all the very best.

      This is my go-to site, but it is nice to see multiple reviews even if it is the same thing getting covered. Unless I am wrong,… I think most,… if not all,… of these guys have regular jobs and yet still spend the time to thoroughly review air guns which can be a full time job in itself. Not to mention the expense.

      I am not sure of what their end goal is,… ( maybe a job/contract like B.B. has?),…. but I seriously appreciate their time, effort and cost incurred.


      • Yeah, I just learned of his passing this week. I was wondering about him because I hadn’t gotten any notifications from him about new gun reviews. The last video I watched brought tears to my eyes. I think he was planning to do a review of the Urban next because there was one on his stand. He was just too weak to get it done. Cancer is such a horrible disease, and he suffered terribly in the last few months. 🙁

  5. BB
    What did you do to remove the barrel as in the photo, Part Two I think?

    This pistol is screaming for a fake silencer with an inner barrel extension to increase the FPS and I was thinking of threading the inside of the outer barrel if it will work. I did it to my pellet firing Barretta and it worked fine. Also considering disabling the dysfunctional blow back action for a few more FPS.
    Evidently it releases CO2 out the rear of the firing pin pushing back and sealing off the intermediate pin in the slide and pushes it rearward.

    Wasn’t long before I figured I may be able to convert the hammer to full auto then it hit me, trigger activated belt !
    It may sound cool and waste CO2 but it would never launch any ammo after the first shot.
    Bob M

  6. Thanks for the discussion of BBs…
    Looking forward to seeing how inaccurate they will be.

    The first shop that I ordered the pistol from would not ship it to me…
    Apparently, 20 pellets in the magazine is potentially against the law in CA.

    Interester in:
    I’ve read somewhere that Sig considers a combat zero to be 10 yards, not 7. So if the sights are set for 10, would you be shooting low at 7? (I keep seeing complaints about the gun shooting low and wonder if this is the reason…)

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