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.

Loading

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.

Velocity

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.

Shot………Velocity
1…………….301
2…………….DNR (did not register)
3…………….278
4…………….DNR (did not register)
5…………….262

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.

Evaluation

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.