Best caliber for use with suppressor, 9mm or .45acp?

.9, Smaller round, smaller sound

.45 is slower though.

Cavalry, the 9mm is actually louder than the .45 out of similar barrel lengths.


The .45 is easier to supress, but both are easy enough to do. I'd personally go .45.

I'd say 45. Low pressure round and most loadings travel below the speed of sound so the sonic crack is not an issue.

If you are using standard pressure rounds then a .45 ACP will be more quite then a 9mm which you will have to deal with the sonic crack.

If you wanta 9mm to be anywhere near a .45 in sound suppression you will have to use subsonic ammo which is much more expensive than standard 230 ball .45 and still isn't quiter.

You will have to use a 147gr bullet to really suppress a 9mm shot. At least that is the popular one. That will slow it down a bit and make it a bit less effective.

Silencers are nothing like in the movies. Think more like a muffler in your car, much quieter, but you've still no problem hearing them when they drive by.

I've shot a slienced Glock in 9mm. Its pretty quiet when you are behind it, but when the owner was shooting it ~30' down the firing line there was no doubt a gun was going off to my right even with my hearing protectors on.

IMHO not worth the cost,tax, and hassle of the ATF paperwork. I'd rather have more guns and ammo to shoot instead. YMMV.

--wally.

I am curious, if you pay the tax and get one suppressor, is it ok to have more than one gun threaded to take the suppressor?

If so you may want to think about what carbines you will or mo=ight want to own.

The 9mm really needs velocity to maintain it's effectiveness, but for a non-defensive gun, the 147 grain loads are just fine. The .45 has a lot of effective loads under 1,100fps and you wouldn't be losing anything by suppressing it.

wally, for the most part you're correct. However, using 230grn loads in a 45ACP, you'd be surprised. Not really louder than a well-suppressed .22lr. (basically, you hear a click, then the thump of the bullet)

I am curious, if you pay the tax and get one suppressor, is it ok to have more than one gun threaded to take the suppressor?

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Yes they don't care what gun you're putting it on, they just want to register the suppressor for 'tax purposes'.

It's like registering a box of band aids.

Todays suppressor technology allows supersonic cartridges to be used with acceptable reduction in ballistic signature.

High velocity .45 acp cartridges appear to be more effective that high velocity 9mm cartridges when used in conjunction with a suppressor as long as there is no need to defeat ballistic armor.
9mm cartridges work better in this context and the 5.7X28 FN cartridge and the 5.56 are even better still while maintaining an acceptable reduction in noise level as long as an urban setting is not mandated.

I'd choose .45, but I'm biased.

I'd say 9mm. Fired side by side, the MP5SD is much quieter than my Mark 23. The bigger the bullet the bigger the boom.

I may have the numbers a bit screwed up but the MP5SD suppressor will reduce the sound signature by 32 decibles compared to unsuppressed signature.

The MK23/Knights Armament suppressor will reduce the signature by 23 decibles compared to unsuppressed signature.

Comparable suppressors mounted to comparable weapons firing comparable ammuntion will reduce signature by comparable levels.

In other words, a .45 acp cartridge moving at 1100 feet per second will sound comparable to a 9mm cartridge moving at 1100 feet per second and both will sound very similar when fired from identical weapons using identical suppressors.

If the .45 is moving at 850 feet per second and the 9mm is moving at 1050 feet per second and both are fired in identical weapons using identical suppressors the sound signature will be less with the .45 because there is no supersonic crack.

The Mk23 will produce a louder sound signature than the MP5SD because there is less barrel and suppressor length to absorb the gasses generated by cartridge discharge regardless of cartridge selection.
Even so, the MK23 with suppressor is pretty darn quiet.

I'm not some sort of specialist here, but my understanding is that if you use a silencer then you want to use sub-sonic velocity ammunition.
The reason being that it is difficult to muffle the sound of the sonic boom that the bullet creates as it whizzes by.
For this reason alone, I would go with the "Slow but Heavy" route and pick the .45.
Sub-sonic 9mm would be going the "Slow but Lightweight" route, which is not really that desirable of a way to go.

I'd say 9mm. Fired side by side, the MP5SD is much quieter than my Mark 23. The bigger the bullet the bigger the boom.

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Comparing an SMG with an SMG suppressor to a pistol with a pistol suppressor sounds like apples to oranges. Also, the pressure and velocity of .45ACP is lower than that of the 9mm.

I asked this a while ago. The general consensus was that in order to suppress well, the bullet should be subsonic. The .45 ACP round is essentially subsonic to begin with. The 9mm would require subsonic ammo, which would decrease terminal performance. You can debate 9mm vs .45 ACP all day long in standard velocity ammo. I, personally, prefer 9mm. However, if I had the choice between standard pressure .45 ACP and subsonic 9mm, the .45 ACP wins, hands down. Ergo, if I was looking to suppress a pistol round, I'd suppress a .45 ACP.

I am, however, not an expert.

Mike

Silencers are nothing like in the movies. Think more like a muffler in your car, much quieter, but you've still no problem hearing them when they drive by.

I've shot a slienced Glock in 9mm. Its pretty quiet when you are behind it, but when the owner was shooting it ~30' down the firing line there was no doubt a gun was going off to my right even with my hearing protectors on.

IMHO not worth the cost,tax, and hassle of the ATF paperwork. I'd rather have more guns and ammo to shoot instead. YMMV.

--wally.
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Not all are created equal. I fired a suppressed MPDSD and a UZI and they sounded like loud cap guns. I fired a 300 Whisper with the action locked and all I could hear was the hammer hitting the firing pin and the bullet hitting the log we were shooting at. I was very impressed.
Pat

If we are discussing pistols using the Browning tilting barrel the .45 will have an edge in reliability.

With a fixed barrel it will not matter.

Polymer framed pistols often require suppressors that provide extra recoil force to ensure the slide cycles properly.

Are there any problems using JHP ammo in a suppressed firearm?

"The bigger the bullet the bigger the boom. "

This is the correct answer. The bigger the hole in the end of the suppressor, the louder it is going to be (when we are talking about similar barrel lengths, similar suppressors etc).



This subject seems to be one of the most misunderstood, and speculated on, subjects of the internet gun boards. In all these threads I see a lot of the same thoughts expressed that I don't nessessarily agree with.
For what it's worth, I have purchased four suppressors so far this year.

Obviously, one question that hasn't been asked that is very important to this discussion would be: best for what ?

Hey, 444?

Which would you say is louder, a standard-pressure suppressed .45 or a standard pressure suppressed 9mm? Note that the 9mm would almost certainly be supersonic, and the .45 subsonic. IOW, would the "smaller hole" theory win out over the "subsonic round" theory?

I mean, I understand we're talking about two different noise-generating sources, here: the sound caused by expanding gasses exiting the barrel and the "crack" caused by a supersonic bullet. I just wonder which carries the day in the final equation. I know the answer would be "C": a downloaded 9mm would be quieter than either...but let's assume standard velocities and standard bbl lengths (circa 5") for both.

Mike