Hey /sci/entists, /k/unt here.
When I fire a round in my gun, the shot bullet has a number of important variables for me.
Mainly:
>weight
>speed
Increasing only the weight of a bullet means the same amount of "energy," or ft-lbs as any other bullet fired (potentially) but the range is changed drastically. The affect on the target can also change with dramatic change in weight but nothing else.
Adding more powder, or using a more potent explosive, roughly means increasing my speed. I could also have a more efficiently designed brass case/chamber or of course, lighten the bullet.
So they are related to eachother but can also be separate.
Other variables matter alot too, pressure inside the chamber during firing of course, but it all translates down to how much ft-lbs you can put into a target, and at what range. The more for each the better. And what directly affects those right before impact is
>speed of the bullet
>weight of the bullet
Now is energy really going anywhere but the velocity of my bullet once it is fired? I know nothing perfect, but is there really an appreciable amount of energy being "lost" to anything but travel of the bullet?
>friction in the barrel
But how do you even change that for a positive effect?
>heat from the firing
Energy that is wasted as heat instead of expanding force?
Excuse my imperfect technical speak, if you could.
cool gun OP. Is that a FAMAS?
What the fuck are you asking?
>>7931005
kinetic energy increases with velocity squared, but only linearly with mass
so increasing the projectile velocity is favorable over increasing the projectile mass
you failed to actually ask a coherent question though
>>7931038
I'm asking if anyone has even gone so far as to go the rifling in place? pls advise
feeble minded OP hasn't asked a question that he hasn't answered.
>>7931040
>2016
>not going the rifling in place
never go full retard
>>7931044
>still using retard as an insult
Umm, don't you know it's the "current year"?
In any system you're going to have some level of inefficiency. As you stated this will mainly be found in the friction between the round and the barrel as well as waste heat.
There are also a few other things that produce inefficiencies. With many firearms the combustion process is still occurring as the round leaves the barrel. This means that there is a lot of usable pressure being wasted as the round exits the barrel. This is why pistol caliber carbines have 3 to 4 times the effective range of a handgun, they can take advantage of that extra energy. The longer barrel helps with accuracy as well, but that's a different matter.
Another thing that can take away from the muzzle velocity of a bullet is any energy that is used to reload the firearm, such as a gas or recoil operated reloading mechanism.
>>7931049
ok bro, but what about sniper rifles?
>Increasing only the weight of a bullet means the same amount of "energy," or ft-lbs as any other bullet fired (potentially) but the range is changed drastically. The affect on the target can also change with dramatic change in weight but nothing else.
The kinetic energy in the bullet is equal to one half of its mass times the square of its velocity. The kinetic energy of the bullet has an effect for sure on its terminal ballistics, but design and material are equally significant.
>I could also have a more efficiently designed brass case/chamber or of course, lighten the bullet.
Are you referring to caseless ammunition? The design of the brass should have very little impact on the pressure developed when the round is fired.
>Other variables matter alot too, pressure inside the chamber during firing of course, but it all translates down to how much ft-lbs you can put into a target, and at what range. The more for each the better.
It's not all about energy. Whether you're concerned more with firing into soft squishy things or hard plates determines how your bulled looks and what it's made of. Only once you get those do you focus on caliber, mass, and velocity.
>Now is energy really going anywhere but the velocity of my bullet once it is fired? I know nothing perfect, but is there really an appreciable amount of energy being "lost" to anything but travel of the bullet?
Until the bullet hits something, it only loses energy from drag.
>>friction in the barrel
>But how do you even change that for a positive effect?
Not significant. Barrels are made of tough steel so that they last more than a few shots, a lowdrag teflon barrel would be worthless.
>>heat from the firing
>Energy that is wasted as heat instead of expanding force?
Again not significant. Heat makes the air expand, which is what drives the bullet down the barrel. "Using" more heat means longer heavier barrels.
I'm not sure what you're even trying to ask.
Energy is going in to the reload mechanism. Also, some gasses leave the action instead of the barrel.
Of course there's some air resistance, and some energy lost due to the way humans handle recoil.
>friction in the barrel
You can't get rid of this without getting rid of riffling, leading to more gas leaks and an unstable bullet.
Also, there may be excessive design flaws on specific models.
>>7931049
>Another thing that can take away from the muzzle velocity of a bullet is any energy that is used to reload the firearm, such as a gas or recoil operated reloading mechanism.
on most gas operated mechanisms the gas is tapped almost at the end of the barrel
also on a piston driven system the piston does not start to move until the bullet has already left the barrel
so the overall losses induced by a gas system on velocity are miniscule at best
>>7931057
what the fuck are you even asking?
>>7931053
>some gasses leave the action instead of the barrel.
unless we're talking about revolvers that's absolute horseshit and something that would result in catastrophic failure
the cartridge expanding against the chamber seals the action
>>7931057
Everybody in this thread is from /k/. All of the /sci/fags are in one of the numerous IQ dick measuring threads or the daily "(insert scientific field that isn't math or physics) isn't really science" thread.
Too lazy for LaTeX
>>7931058
I'm asking how many clips it would take before my FAMAS could go the rifling in place, man. Shouldnt be hard, don't you have a phd?
I'm so confused as to what the question even is.
>>7931072
Don't you have better things to be doing?
>>7931072
two
unless you add a shoulder thing that goes up to the clipazine, then five, but that's trivial
>>7931077
finally a serious answer to the question. Thank you my intellectual scientist friend, I swear I will put this knowledge to good use, scout's honour.
If you take temp drop to be negligible eqn becomes simple.
