I have a hybrid 46 and really like it. I really like the fact I can use it on pistols and rifles.
However it is a little large and heavy on the pistols, though I have not a single issue with it on the pistols I have tried it on.

I was thinking about another can.
My question is, how does the sound reduction/performance of a dedicated 9mm can compare to a similar size/shape/length 45 can on the same 9mm?

Would I be better off getting dedicated cans for each caliber (something I may not be able to afford to do), or can I use the 45 can on the 9mm without much loss of performance?

I have shot my hybrid 46 on my 9mm, but I do not have a dedicated 9mm can to compare it to, to know how much difference there would be.

And on that note, if it would be a better choice to use a 45 can on both 9 and 45, what good suggestions are there?
Length is not really a concern, but smaller diameter and lighter weight would be a good plus.
Looking at the silencerco osprey 2.0 in 45. Seems like a decent choice. The numbers on their site show very similar performance between the 9 and 45 versions. I also like the fact you do not have to have suppressor sights and it is a good bit lighter than my hybrid 46.

a few things you may find telling are that, .45 cans are almost always longer in the same product line, some companies that make short and light versions of their 9mm cans don’t bother doing so with their .45 cans, and modular .45 cans’ short and long configs tend to straddle typical 9mm cans’ lengths, with short config being very close to a typical 9mm full size.

You’ll get less blowback in my limited experience, though that doesn’t seem to be a huge problem with most pistol/can combos. The likelihood of 9mm baffle/cap strikes goes down.

I mostly tend to use .458 cans on PCCs and 9mm cans on pistols.

I'm glad I went 45 can for all my pistol needs. Because really the joy of shooting suppressed pistols is small, the real world use of it is almost negligible. So I get to shoot my revolution 45 on 1911s for fun, and it can live on a 9mm PCC for HD if needed.

I reached the same conclusion so I bought a Sico Maxim 9.

If you don't mind a bulky pistol can that has other uses the YHM R9 can do centerfire rifle.
Mine is on a 350 Legend.

I have 1 of each. I have not mounted my 45 can on anything but a 45 though, so can't really offer comment on the performance. The 9mm can lives on a PCC and being 3 lug it hasn't been moved to anything but an MP5 clone.

TBAC Fly 45. If you can swing the dollars, it's very light and I am told quieter than the Fly 9 on a 9 mm host.

Go dedicated. You’ll likely end up doing it eventually anyways.

I like 9mm cans on 9mm. They generally sound better and are smaller/lighter.

I used to feel that way till I switched my pistol cans to Ez-lok. Constantly tightening, needing multiple pistons to use them on multiple hosts at the range that day. It made shooting pistols suppressed kind of a pain.

EZ Lok on a .45 can means you never have to swap pistons for sub calibers. You just need the muzzle adapters.  Other than a little more length & weight the 45 can suppresses fine on 9mm with potentially less noise at shooters ear and less blowback.  With conventional pistons loosening risk, the over bore is a safety margin for front cap strikes.

If you’re only going to have one pistol can I’d definitely buy a 45 silencer.  I’ve shot my Obsidian 9/45 back to back and I could tell the 45 was slightly louder but bystanders couldn’t tell a difference.

Someone above mentioned the Fly 45 is quieter than the 9mm version.  On my Henry X lever shooting 38 specials the Obsidian 45 is quieter to my ears than the Obsidian 9.  Just another positive to go with a 45 can.  That said I’m addicted to suppressors so I have to have multiples of everything.

Looking at silencerco's website. They list the osprey 9mm as average Db 129.5. They list the osprey 45 with 9mm as 128.9 (and 45 as 130.4)

So they are showing almost the same performance in 9mm with the 45 version as they do with the 9mm version.

Weight of the 45 version is 9.2 oz which is pretty significant compared to my hybrid 46 at 14.1 oz.

Depends a good deal on the design. I have a SilencerCo Octane 45 and Octane 9 and really cannot tell the difference with 147gr or 158gr subs. I will say that my Griffin Revolution 45 is a little louder with 9mm than when I use the 9mm endcap, but there's more blowback.  It seems, logically, that the dedicated can will be quieter, but its really dependent on too many factors that go beyond the caliber.

Was doing a little more looking online and ran across this old silencerco video where they shot different calibers through the different models.




Shooting the 9mm through the 45 osprey was around 127db.
Shooting 9mm through the 9mm osprey was around 124db.
The 9mm through the 45 can had a louder first round pop than when shooting it through the 9mm can.

Not having been around many suppressors, can anyone tell me how big/noticeable of a difference there is with 2-3db?

2-3dB is minimal. Also, those appear to be numbers at the muzzle. .45 cans often do better at the ear with 9mm than dedicated 9mm suppressors but are a tad louder at the muzzle. I tend to care more about ear numbers. The video, below, is a good illustration. The Fly 9 and Fly 45 are two of the best pistol suppressors out there:

The reason for the 9mm performance is that the Osprey 45 is longer and has an additional baffle stack, and that counteracts shooting 9mm through a .45 hole in the Osprey.

My vote would be to buy a good 45 can and do either cam-lok or EZ-lok.  My SiCo Octane 45HD with Griffin's Eco-flow baffles sounds absolutely spectacular on 9mm and 45 ACP.  I hardly ever shoot my Optimus 9 in pistol configuration, or at all for that matter.

On a handgun, weight REALLY matters if you are going to shoot a lot. So I think the few ounces you save on a good 9mm can are definitely worth it. FWIW, I also own the Hybrid 46, and love it, because it is good at just about everything EXCEPT on handguns.

Well stopped into my local gun store on my way home (where I got my other two suppressors) and low and behold, they had a osprey 45 setting on the shelf. They had just got 2 of them in.
I had just asked about them a couple weeks ago and they did not have any, but said had them on order and no idea when they might show up.
I was able to compare it side to side with a hybrid 46 and the weight difference is substantial.

I said screw it and bought it.
Maybe I'll get lucky like some of you and get my approval in a few days. But knowing my luck, it will be another 7 months.

That's what I ended up doing.  My son just ordered a 9mm pistol can after shooting his .45 pistol can on 9mm and .45.

Not sure what this is worth because I can only compare my Obsidian 45 in short configuration to my Odessa 9 (I prefer seven baffles) but honestly the sound is about the same to me, as is the blow back.  
I do like the Odessa due to the smaller diameter but am very happy with both on pretty much any handgun that I've run both on. That includes my SIG P365XL, Beretta 92FS and M&P 2.0 in 9mm.  

The Obsidian 45 is a bit much on the 365 though.  Larger than the gun....

Shaw Arms makes one that does both. Kind of hard to explain, but it has baffles that are cleared for .45 and then cups that fit into them that restrict the opening down to 9mm. If you take the cups out, it clears .45. Put the cups in to optimize for 9mm.


https://www.shawarms.com/products/thundercan-41242-11894-5176