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Old July 6, 2012, 09:28 PM   #1
CCCLVII
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What would happen if you suppress a revolver

I am not talking about a nagant (how ever it is spelled).

I realize that it would force more of the blast out side the cylinder gap but would it not force more of the blast if the barrel was longer? I mean would not the blast from the cylinder gap be more from a 10 inch barrel than from a 4 inch barrel with a 6 inch suppressor on it?

can any one explain this to me is simple easy to under stand (read: dummy) words?

I have a revolver in 30-30 (BFR) that has a round barrel that should be very easy to thread if a suppressed revolver would work...
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Old July 7, 2012, 12:41 AM   #2
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I'm sort of feeling my way through this, but it seems like it makes sense.

I don't think it will make the blast out the barrel/cylinder gap appreciably worse because I think most of the gas that escapes through the gap escapes as a result of the pressure being high while the bullet is obstructing the bore. A silencer doesn't change anything while the bullet's still in the bore, it only helps contain/slow the gases after the bullet leaves the bore.

There's still some pressure after the bullet exits, but not nearly as much as there was before the bullet exited the muzzle. With the bullet out of the way, the pressure is going to drop very rapidly and very dramatically.

So my gut feel is that to the extent that there's a lot of noise escaping out the barrel/cylinder gap, it's happening when the bullet is still in the bore, before a silencer is going to have any effect at all on the system.

I don't know exactly how to compare the muzzle blast to the barrel/cylinder gap blast, but my gut feel is that it's not going to be as dramatic since not as much gas can escape through the smaller opening. So a decent suppressor would probably make a significant noise reduction, even on a revolver by operating to reduce muzzle blast. While it won't do anything to quiet the noise caused by gas escaping between the barrel/cylinder, it also won't do anything to make it significantly louder either if I'm thinking about everything properly.
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Old July 7, 2012, 08:23 AM   #3
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You would gain a few inches of barrel length.

Can't help but recall the "suppressed" Pythons from Magnun Force
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Old July 7, 2012, 08:27 AM   #4
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Wouldn't make any difference at all.....the gas escapes thru that gap is not affected by barrel length

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Old July 7, 2012, 09:19 AM   #5
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I can't help but think that it might actually be slightly quieter with a SHORTER barrel.

Basically, the gas escapes from the gap because the bullet is blocking the barrel. As soon as the bullet leaves, pressure drops rapidly by way of the muzzle. If the bullet spends less time in the barrel (shorter barrel), it may blow less gas out the gap.

Whether or not the fractions of milliseconds difference produces any discernible real world difference is another matter.

On the ther hand, the shorter barrel means that the supressor has to deal with more pressure too.

Might well be 6 of one 1/2 dozen of the other.
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Old July 7, 2012, 02:17 PM   #6
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Quote:
You would gain a few inches of barrel length.
To the extent that the suppressor really does make the barrel look effectively longer, the amount of gas that escapes from barrel/cylinder gap seems like it would be increased since the bore pressure is staying higher longer.

That said, I'm not sure that a suppressor would really make the barrel look longer from the standpoint of keeping the bore pressure high because there's not a gas seal while the bullet is traveling through the suppressor like there is while the bullet is in the bore.
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Old July 7, 2012, 04:35 PM   #7
Glenn E. Meyer
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There was a suppressed Ruger revolver that was written up in one of the Gun Digest's Assault weapons books quite a few years ago. It made an appearance on X-Files. Had lots of mods and I have no memory for the details.
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Old July 7, 2012, 06:24 PM   #8
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Quote:
A silencer doesn't change anything while the bullet's still in the bore
Are you sure about that?
My basic understanding of a suppressor effect on pressure is:
At some point the bullet passes holes drilled in the barrel. These holes lead into the "can." This extra area in the can significantly increases the volume of the gas, decreasing the pressure. So, once the can allows expansion out of the barrel into the suppressor, the force acting on the bullet is reduced. As a result, the pressure in the barrel is 1/2, 1/4, or even less when the bullet leaves an unsuppressed barrel. The results in the reduced noise level. The end effect is suppressors increase velocity, but not beyond the same length barrel extension. This assumes a closed system such as a bolt gun or automatic, not a revolver, and an "integrally suppressed" gun would reduce velocity.

Now, as far as a revolver. I don't see how it would work as well as a closed system, BUT, if so much pressure is escaping out that gap then how do revolvers work in the first place? If the pressure is staying in then so is the sound. So...
Please give it a try and give us the result.
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Old July 7, 2012, 08:20 PM   #9
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If there's venting in the barrel added as part of the suppressor install then that's a very different situation compared to simply adding a suppressor to the end of an otherwise unmodified barrel.

You are correct. If the barrel is vented to lower velocity then the pressure in the bore is reduced after the bullet passes the first vent.
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Old July 7, 2012, 08:31 PM   #10
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The suppressor designs i have looked at, and they are for the most part rather rudimentary, have venting in the suppressor, so the suppressor acts as something like an extended barrel with limited venting.

If the revolver is increasing the pressure such that more is escaping the cylinder gap, than the internal barrel must also be at higher pressure so performance will not drop.

If you have a 4 inch barrel with a 6 inch external suppressor, at some point after 4 inches gas will be vented into the can. This will decrease pressure significantly compared to a 10 inch barrel. I don't see how this will cause more pressure at the gap than a 10 inch unvented barrel, although obviously more than a 4 inch barrel. You would likely get the ballistic performance of something like, IDK, an 8 inch barrel out of the 4 inch + 6inch suppressor(I don't really have any idea behind a number between 4 and 10).
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Old July 7, 2012, 08:39 PM   #11
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Old July 7, 2012, 11:10 PM   #12
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Quote:
...so the suppressor acts as something like an extended barrel with limited venting.
Isn't there usually significant clearance between the suppressor and the bullet? I had always assumed that the suppressor "bore" was signficantly larger than the bullet diameter...
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Old July 9, 2012, 12:41 AM   #13
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Quote:
There was a suppressed Ruger revolver that was written up in one of the Gun Digest's Assault weapons books quite a few years ago. It made an appearance on X-Files. Had lots of mods and I have no memory for the details.
This is actually something that I just found out about yesterday.

Knight's Armament Company created a suppressed Ruger Super Redhawk revolving carbine intended for use by special forces. The gun fired tricked out .44 Magnum rounds that contained .30 caliber projectiles and some sort of piston-like device that would telescope out and seal the gap between the cylinder and forcing cone.

I believe they also developed a GP-100 based version. I don't believe there was any serious production of them, but there's not a whole lot of info out there on them.

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Old July 9, 2012, 09:54 AM   #14
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The user agreement prohibits me from posting what I think of how that that gun looks.

I will say good on Knight's for their ingenuity...
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Old July 21, 2012, 12:39 AM   #15
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Quote:
Isn't there usually significant clearance between the suppressor and the bullet? I had always assumed that the suppressor "bore" was signficantly larger than the bullet diameter...
I thought that too, then I toyed around with getting one. You can build them on the barrel where you just vent it into the can with some holes. In that case it is obviously in contact. The most common design seems to be with washer like discs(baffles/wipes) a little larger than the bullet. For whatever reason, maybe the same as why the cylinger gap works, the pressure seems to stay more or less behind the bullets. SOme of this type use consumable baffles/wipes which the bullet pierces(mostly older designs).

I couldn't remember the term "baffle" so turned to wikipedia for a quick reminder. The article there seems reasonably well written and factual to the limits of my knowledge.
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Old July 21, 2012, 05:46 PM   #16
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The exploding gas behind the bullet causes it to move, the air in front of the bullet has to be moved also this takes much air movement in front of the bullet, the silencer is also catching/blocking this air so the silencer is going to cause more backpressure than an open barrel in longer length would.
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Old July 22, 2012, 12:33 AM   #17
johnwilliamson062
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assuming the suppressor does not use wipes, why would it be less open than an equal lenght barrel? If there is a slight clearance it should be more open.
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Old July 22, 2012, 12:59 AM   #18
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Because like the muffler of a car it is designed to capture moving gasses and delay their exit.
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Old July 22, 2012, 02:19 AM   #19
johnwilliamson062
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If you have a ten inch barrel and the bullet leaves in z seconds the gas leaves immediately after the bullet.

If you have a 4 inch barrel and 6 inch suppressor the bullet clears the suppressor at the same time as the 10 inch barrel, but the extra clearance around the baffles in the suppressor allows gas to get ahead of the bullet and exit before the bullet. Maybe. I can't see how the gas leaves later than immediately following the bullet.

The volume of the barrel is very small. on a 10 inch 50 cal(1/2 inch diameter) barrel the volume is only 2 cubic inches. On a 4 inch 50 cal barrel with a 6 inch long 2 inch diameter suppressor attached the volume is about 20 cubic inches. A pressure of 60,000 psi in the ten inch barrel is reduced to 6000 psi in the barrel & suppressor combination. With smaller caliber bullets the difference is much greater. The suppressor works not b/c it spreads out the gas leaving the barrel over time as much as the gas is at lower pressure when the system is opened. All rough calculations, and my physics is nowhere close to the level needed to be certain of how that works, but as I understand it...
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Old July 22, 2012, 11:02 AM   #20
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It's not that the gas doesn't leave immediately behind the bullet. It's PUSHING the bullet, it has to leave immediately behind it. Once the bullet reaches the suppressor, the gases have lots of other places to go, so they do. The gases always follow the path of least resistance. There are now LESS gases immediately behind the bullet. Less pressure, slower moving, less noise.
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