Firearms and suppressors.

[Reflector]

A well designed silencer without any wipes (Or bafflestrike) should not induce velocity drop. Once the bullet has left the muzzle and the zone of gas interference (Ex: 'Muzzleblast') it does not gain any more velocity. A silencer\'s chamber sits in that forward area and functionally contains the muzzleblast (And in this case: 'The acoustic report') of the muzzle blast within itself*.

*Not necessarily entirely. There is still pressure differential between the interior of the silencer and the environment, you will just get a greatly reduced difference -> Less loud report. There are other tricks where the flow of gas can be used to induce resonance and work in the manner of 'noise cancellation' but gunshots are typically broad spectrum compared to cancelling out specific frequencies. Regardless, primary mechanism is through reducing the muzzleblast.

Silencers DO NOT rob you of projectile velocity in practice unless there is actual physical interaction between the components of the silencer (Ex: 'Silencer with wipes').

As for a conic compressor attachment: Don\'t bother, as previously started before the nozzles on real life rocket engines are designed for the maximum efficiency obtainable at the time they\'re made. (Read: 'Oh whoops we found that we goofed on the FEA model, so the next production model will have slightly higher output.') You\'d only obtain a theoretical possible gas velocity increase with a massive drop in your efficiency but you\'re not going to get anything from this.

Not to mention you\'re running into the problem of specific impulse. I mean you could strap on turbines on the bottom of your rocket and have lower fuel consumption but with a heavier engine you\'re not going to go any further.

[GoodGuy]

however, wont the bullet go supersonic if it can go supersonic, therefure cancelling out the suppressor?

[Themohawkninja]

however, wont the bullet go supersonic if it can go supersonic, therefure cancelling out the suppressor?

If the bullet can go supersonic it will, but many of the firearms that utilize suppressors are either sub-sonic (in the case of pistols, and SMG\'s), or are used at ranges that the sound can\'t be heard anyways (like sniper systems). Also, I believe that due to the bullets\' small size, it only generates a small sonic boom.

[Dobrodav]

As Reflector mentioned above, effective size of nozzles compared to overall engine power is function of outside static pressure (altitude in atmosphere). Therefore, size of nozzles optimal for vacuum (bigger), is not optimal when ascending from atmosphere (they should be smaller).

[dr_anonymous]

but many of the firearms that utilize suppressors are either sub-sonic...

Actually, it\'s not so much the firearm as the ammunition. You can pretty much buy (or make) ammo with less powder, therefore granting it less muzzle velocity. Works great for pests and small game. Of course, the price you pay is a quicker drop.

Well, somewhat offtopic unless a project HARP or other mass driver is ever implemented.

[Vostok]

As Reflector mentioned above, effective size of nozzles compared to overall engine power is function of outside static pressure (altitude in atmosphere). Therefore, size of nozzles optimal for vacuum (bigger), is not optimal when ascending from atmosphere (they should be smaller).

The optimum effective nozzle size for a vacuum would be infinite, would it not? (technically)

[Themohawkninja]

Actually, it\'s not so much the firearm as the ammunition. You can pretty much buy (or make) ammo with less powder, therefore granting it less muzzle velocity. Works great for pests and small game. Of course, the price you pay is a quicker drop.

Well, somewhat offtopic unless a project HARP or other mass driver is ever implemented.

Yeah, I meant to say that. Although, I\'m surprised that you didn\'t ask what a subsonic firearm is, because that doesn\'t even make sense.

Also... what\'s project HARP?

[sal_vager]

[mod]Sepearated and moved this Off-Topic as it's turned into a discussion on firearms.[/mod]

[Dobrodav]

The optimum effective nozzle size for a vacuum would be infinite, would it not? (technically)

There is a limit placed by theoretical maximum of gas energy, but they can be quite big. In practice, nozzles are quite heavy, and engineers must take that in consideration when deciding size of them on engines placed on upper stages in coordination with whole craft characteristics. But even with that restrictions, modern rocket engines have efficiency up to 70 %, much better, than any other engines.

[Herpderpsslerps]

That and in the case of people using suppressors, most of them use handloads that don\'t push the round over the speed of sound, keeping them sub sonic to prevent that distinctive crack.

Though some companies make .22 ammunition that is more or less just a primer, its very quiet when shot out of a rifle, comparable to a mid power air rifle.

[4 IN 1]

Most of them use handloads? Must go tell Christ Costa and Travis Haley that they are doing wrong by using manufactured ammunition with a can =P

[Herpderpsslerps]

Most of them use handloads? Must go tell Christ Costa and Travis Haley that they are doing wrong by using manufactured ammunition with a can =P

You ever shoot? A properly tuned load can make the rifle do remarkable things. Can take a rifle that is shooting 1.5 Minutes of angle and take that to less then a minute of angle.

[OnyxAltair]

When EVA\'s come out, some one should make a FPS mod XD