Just picked up a P320 XCarry Legion and am wondering what the most recent suppressor experiences are. Looking on the web, I’ve seen a bunch of experiences:

P320s are only reliable with certain suppressors and bullet weights

They only work reliably with the 8oz Sig ModX-9.

Need to use lighter weight recoil springs.

Gun needs to be broken in 200-1000 rounds first.

A few say they haven’t had any problems using non-Sig suppressors.

Looking at using my Gen 1 Osprey 9, or perhaps Obsidian 45, but the Osprey would be my first choice.

There are gazillions of 9mm suppressors. You can find good info here, PewScience, NFATalk, and YouTube. Personally, I just got a Dead Air Wolfman and Dead Air Mojave out of NFA jail, but I haven't had time to try either yet.

As far as ammo, 147 grain 9mm ammo will be subsonic. When you're lookimg at ammo, if the velocity is lower than 1080fps (the speed of sound, varies depending on altitude) it will be quieter.

Why? There are two sources of sound when a gun is fired - the sound of the explosion of the gunpowder and the sonic boom caused by a bullet passing through the air faster than the speed of sound. Using subsonic ammo eliminates the sonic boom, and using a suppressor reduces the sound of the explosion. So whatever caliber you're using, if the fps is less than 1080, your shots will be quieter.

If you can only afford 1 can, go with a larger caliber. If you can afford more, the caliber of the can closest to the caliber of the bullet will be quieter. Shooting 9mm out of a 9mm can will be quieter than out of a can made for .45 caliber. Likewise, .300BO will be quieter out of a 7.62 (.308 caliber) can than a 9mm (.38 caliber) can. Weight may also be a consideration.

I hope that helps.

Thanks, but my question has nothing to do with how good a suppressor is or the need to use subsonic bullets to prevent the sonic crack. I know how suppressors work, what ammo to use in them, and already have the suppressors that I have. The question is suppressors that will work reliably with a P320 carry and not cause issues like stove piping or other feed issues.

Although a common misconception and it’s not directly related to the question so please pardon the drift, but for those interested the speed of sound in air is dependent primarily upon temperature, not altitude.

“The speed of a sound wave in air depends upon the properties of the air, mostly the temperature, and to a lesser degree, the humidity.”
https://www.physicsclassroom.c...2/The-Speed-of-Sound

Statements like the above appear on many sites.

One source of confusion seems to be the assumption that increase in altitude automatically results in decrease in temperature. That’s evidently because of the use of “standard” temperatures for various altitudes in calculations, but of course that’s not always true. Where I live at 10,000 feet, for example, the standard air temperature is 23.3° Fahrenheit, but today it hit a sweltering 76° for a few minutes ( ).

https://physics.stackexchange....ough-the-air-density

One study I found indicates that the speed of sound at very high altitudes varies independent of temperature, but they’re not the places anyone will be firing a suppressed pistol.

You're overthinking this! The P320 X-Carry Legion comes with a Threaded Barrel and you indicate you already own an Osprey 9, and possibly an Obsidian 45 as well. I'd lean towards the Osprey myself as it's a lighter can and a VERY good performer, plus it looks BadAss on most any Pistol. Just head to the range, thread on your suppressor and shoot it...Then report back!

I'd go with 147gr ammo as it's subsonic by design, and that's the whole point if you want to suppress it anyway. Yes, 'your' gun may need some break-in before it shoots 100% reliably, but that 'can' be the case w/ ANY pistol, and you won't know until you shoot it. Go have fun with your new gun!

Just another point. 147 gr 9X19 ammo is NOT ALL subsonic. There are defensive rounds that are supersonic. The routine practice 147's and even many of the SD 147's are, but you should check the ammo speed before assuming it is subsonic.

I would be interested in you naming a brand (or multiples if they exist) of ammo that is not subsonic in 147g at std. conditions of temp/altitude with a non +p or +P+ round.