.45 caliber suppressor

[LavaRed]

I'm designing a suppressor for my 1911 pistol. I decided to benchmark Knight's Armamament Industries .45 Suppressor, because it is reputed to be the best commercially available .45 suppressor, particularly for dry fire.
External dimensions are only slightly smaller than my previous cans, and the sound reduction rating, 28-38 dB, is less than what my MK.2 Can is capable of by some 10 dB.
But I want to better my record 110 dB rating on the MK.2 . My MK.45 can should be able to do 100 dB at least. So I have a few novel ideas I want to discuss with you guys:

1) Adding a heatsink around the expansion chamber. Basically a spacer made of copper, aluminum, or some other material, threaded inside, so as to increase sruface area, that can dump heat from the chamber quickly and efficiently. Suggestions on materials that are better at being heatsinks, and ways to increase surface area, are appreciated.

2) Adding a reflex cone at the rear of the blast baffle. Do you think it will really help?

3) Gas relief ports on the blast baffle. Do I keep them?

4) Thinning out the baffles. Should I leave them the same thickness as in my MK.2 Can, or is it ok to thin them out to increase the space between baffles.

5) Adding a "Diafragm baffle". A very thin, sheet metal "Baffle" washer between the blast and second baffles, which vibrates from the gas stream, changing the frequency of the exit gasses. Discussion on different materials are appreciated.

6) Shape and spacing of baffles. The current shape and spacing on my MK.2 seemed to work well, but would there be a better arrangement that any of you would suggest? Are flat baffles really the best, or is there a better possible shape? (Assymetrical baffles are known to cause the largest POI shifts, so I'd rather avoid them).

[Vargus]

or is there a better possible shape?

Conic, radiused, or hyperbolic should all be better than flat baffles when you have an insulating substance to catch most of the sound. Such baffle designs should also help reduce recoil.

[Groundhog whacka]

Lava I found this link I had saved a while back, it has some interesting ideas.
http://cncguns.com/projects/22silencer.html

[reggie_love]

Lava I found this link I had saved a while back, it has some interesting ideas.
http://cncguns.com/projects/22silencer.html

*Wants CNC machine so bad*

[Vargus]

*Wants CNC machine so bad*

More fun to do everything by hand. ;)

To wit, I'm going out and snagging up a $200 Clarke lathe tomorrow. Normally they are sold for $550 and it has lots of features that you can only get with lathes costing a bit more than that, except the bed travel is a couple inches shorter (10"), but the cross slide travel is relatively long. (7")

[BadShovelhead]

Suppressing a .45 pistol sucks. It's one of the worst possible handgun rounds you could use.

Try 9mm.

[Random_Looney]

;)He already has suppressed a few 9mm weapons, including at least one submachinegun.

I am considering taking a CNC class for my doodad. I hear school is good in this kind of economy, even though that's not what they mean ;)

[LavaRed]

Suppressing a .45 pistol sucks. It's one of the worst possible handgun rounds you could use.

Try 9mm.

By all means, tell me more. Almost every source I had read so far said the exact opposite. They said .45 was easy because it was already subsonic. So I am most interested to learn from your experience.

[Random_Looney]

By all means, tell me more. Almost every source I had read so far said the exact opposite. They said .45 was easy because it was already subsonic. So I am most interested to learn from your experience.

The diameter of the .45 as opposed to the smaller 9mm allows more gas to escape. So subsonic 147 grain 9mm ammunition can theoretically be quieter than 230 grain .45 ammunition, from what I have been told. I try to always use hearing protection now, so I can't tell.

[BadShovelhead]

By all means, tell me more. Almost every source I had read so far said the exact opposite. They said .45 was easy because it was already subsonic. So I am most interested to learn from your experience.

I guess if someone can't find subsonic ammo in any other caliber..

A suppressed .45 is still very, very loud. Also unwieldy. It sounds like dropping a pallet of bricks from chest height to the floor.

[The Swede]

http://www.youtube.com/watch?v=ETVSlUVqjfM

Very loud? Dosen't sound much more than LavaReds previous movies.

[BadShovelhead]

Home video cameras don't capture very much of the sound spectrum.

[Vargus]

Home video cameras don't capture very much of the sound spectrum.

Not only that, ofttimes the sound it is trying to record is louder than the mic can handle so the playback is quieter. But generally, mics in consumer grade stuff don't have a flat frequency response, and that's why it can't capture all of the audible spectrum.

[LavaRed]

I would guesstimate that the .45 can in that video is doing around 120-130 dB.
The typical 9mm can using supersonic bullets does around the same.
I managed 110 dB with full power 9mm ammo and flat baffles, so I figure that I can at least get the same with .45 caliber.
But I expect less gas to leak around. The 9mm suppressors had 15mm diameter holes all the way, and I plan to keep those same holes for .45; therefore, less gas will leak.

What I'm debating is whether to build a whole new can for .45, with a changeable baffle system I designed, or to stick with the same old cans I have and just get a new rear endcap built for it.

[Vargus]

I would guesstimate that the .45 can in that video is doing around 120-130 dB.
The typical 9mm can using supersonic bullets does around the same.
I managed 110 dB with full power 9mm ammo and flat baffles, so I figure that I can at least get the same with .45 caliber.
But I expect less gas to leak around. The 9mm suppressors had 15mm diameter holes all the way, and I plan to keep those same holes for .45; therefore, less gas will leak.

What I'm debating is whether to build a whole new can for .45, with a changeable baffle system I designed, or to stick with the same old cans I have and just get a new rear endcap built for it.

How are you making the baffles? Are you just using off-the-shelf flat washers and boring out their inner diameter out or what?

I guess small machine tools are hard to find down there?

[LavaRed]

How are you making the baffles? Are you just using off-the-shelf flat washers and boring out their inner diameter out or what?

I guess small machine tools are hard to find down there?

There's an experienced machinist a few blocks from my house which will do quality work really cheap. I just hand him my blueprints and a wood or cardboard mockup.
But the flat baffles were simply off the shelf stainless steel washers which were grinded a bit on their OD to fit the can; the ID was left the same.

Down here there's even places that do CNC machining, but its a bit more expensive and they probably wouldn't take anything gun related, but there is lots of experienced machinists with their own machine shops which can do wonders. If my guy wasn't so prickly about doing stuff that borders on lawbreaking, he could have already made me barrels and guns for sure. He already reforged an heat treated a bulged out barrel on the MPK, leaving it like new; he just won't be arsed into making one. That and its kind of hard to find the best metals. So the guy is only as good as his stock in the end.

[Random_Looney]

I am definitely going to try and take one of those CNC classes or something after work this year.

Though I won't be able to help much on the suppressor end, as I don't want to be bothered with the paperwork and I refuse to break the law (except perhaps speeding, jaywalking, etc.), but I may be of service on legal, unregulated things over here.

[Vargus]

There's an experienced machinist a few blocks from my house which will do quality work really cheap. I just hand him my blueprints and a wood or cardboard mockup.
But the flat baffles were simply off the shelf stainless steel washers which were grinded a bit on their OD to fit the can; the ID was left the same.

Down here there's even places that do CNC machining, but its a bit more expensive and they probably wouldn't take anything gun related, but there is lots of experienced machinists with their own machine shops which can do wonders. If my guy wasn't so prickly about doing stuff that borders on lawbreaking, he could have already made me barrels and guns for sure. He already reforged an heat treated a bulged out barrel on the MPK, leaving it like new; he just won't be arsed into making one. That and its kind of hard to find the best metals. So the guy is only as good as his stock in the end.

I don't blame the guy. After watching some barrel turning and rifle cutting videos (http://www.demonoid.com/files/details/1173324/13165812/), it looks like you need some very specialized equipment and lots of time. Although I'm sure a master machinist will have little trouble figuring out how to make all the parts.

If you don't have a demonoid account, PM me for an invite.