Supressor size vs. powder charge

[hemiford]

I have not done much research on this, but it occurred to me that
there might be, or should be, a relationship between the size
of the supressor and the amount of hot gas coming out of the
barrel.

A bigger engine needs a bigger muffler to get down to the same
noise level as a smaller engine.

How far off am I ?

Maybe this was all known 100 years ago and I'm late to the party.

 

[BallisticsGuy]

In classical suppressors volume is part of the equation and not a trivial one. So is how the baffles are laid out, their shape and number of them and the internal design of gas flow passageways. With big powder charges the thing that seems to matter most in my opinion is material selection since you don't want the can actually blowing up or the baffle stack turning to powder and fragments. You can get away with an aluminum can on a .22lr but not on a 300WM. Materials selection defines what performance limits you can push the design to.

Mufflers and suppressors work the same way, by cooling and slowing down hot gasses. Mufflers depart from there by means of designs that try to have individual exhaust pulses cancel each other out and add sound attenuating materials to the mix. A firearm suppressor is focused purely on slowing the gasses and pulling as much heat off the gas as possible without interfering with the forward travel of the bullet. Car mufflers are not usually straight through affairs. They have lots of 90 and 180 degree turns inside.

In a suppressor it's all about pulling energy out of the gasses. You can do that by giving them room to expand before discharging them to the atmosphere, or by transferring the heat to some solid or liquid media and by slowing the gasses down dramatically. All three are done in a suppressor to some extent. The capacity for a suppressor to remove energy in one of those ways decreases the need to be able to do it in the others. Balance right. So if your baffle stack can slow the living pee out the gasses and pull a ton of heat out without being physically large then you can end up with a relatively small suppressor. In reality, yeah, size matters to a point but only insofar as the other elements mattered too.

 

[J E Custom]

I have not done much research on this, but it occurred to me that
there might be, or should be, a relationship between the size
of the supressor and the amount of hot gas coming out of the
barrel.

A bigger engine needs a bigger muffler to get down to the same
noise level as a smaller engine.

How far off am I ?

Maybe this was all known 100 years ago and I'm late to the party.

You are not very far off.

In theory, a suppressor has to consume all of the gas to be quite. This is normally impossible because of the amount of gas and the size required to contain it.

The materials it is made is important for heat absorption and strength as the other poster stated.

The more heat it absorbs the lower the pressure drops and gas volume is reduced. Powder expands by a ratio 1200 to 1500 to 1 volume of powder,depending on the powder type and pressure is somewhere between 10,000 psi to 18,000 psi at the muzzle in a hi powered rifle. This is the reason that they work so well on a 22 LR. (Small volume of powder and very low pressure at the muzzle.

It would almost impossible to build one for a 50 BMG that would be very effective that wouldn't be huge.

So to answer your question, Size does matter based on powder volume. Materials, design and strength also contribute to how well it works.

J E CUSTOM

 

[MudRunner2005]

JE is correct. The reason suppressors are rated for "cartridges up to .300 WinMag" is because they are built to functionally suppress cartridges no more than .30 caliber, and no more than maximum powder capacities and pressures that at .300WM can produce at the muzzle. This is why some .45 Auto pistol suppressors are rated up to subsonic .300 BLK. And why some rimfire cans can handle .17 HMR and 5.7x28.

That's why I've been doing research about how conservative the cartridge ratings actually are (still haven't found an answer yet)... Because I don't have a 300RUM, but if a suppressor can handle no more than a .300WM, then I would have to buy a .300RUM rated suppressor for my .300 Ackley, since it holds more powder than a .300 Wby, but less than a .300RUM. Which is why I want a Thunderbeast Ultra 9 for my bolt-action hunting rifles, and an Ultra 7 for my .300 BLK, 6.5 Grendel, and 5.56 rifles.

I wish I could sell one or 2 of my offroad trucks...I'd have a book of stamps on their way to the BATFE for approval tomorrow. Go ahead and just send them all out at once.

 

[RangerWalker71]

All the above post's are spot on. Where you lose gases due to over bore. IE 338 can, 30 cal bullet, or 6.5 bullet. You will hit a point of dimensioning returns.
I have found that a 338 can will work great on a 300WM, 300 RUM, and 300NM. With the over bore you lose gases, but the volume over comes that. In Mil-Spec meter testing on a 26" barreled 300NM, the 338 can is 3-6 DB's quieter.

It really comes done to what your wanting to to.

If you have questions please call me at 816-718-9489.
RTLW
Steve

Sorry just posting on this tread. Been out on vacation last week.