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Basic understandings?? aka miss information.

sailnaked

my understandings are such
momentum(impulse) = mass X velocity,
more velocity means faster time to target and less drop at the target.
more push / velocity (accelerarion) in the barrel equals more velocity after it leaves the barrel. so in some sense more powder should equal more push.
now this is where it gets tricky:
smaller bullet will go faster if they have enough barrel and the powder burns fast enough.
heavier bullets will go faster because they get more push by the powder longer and they have more mass. (feel free to argue this but only partially what I am looking for.)
lets assume for this case that we want faster bullets and the ultimate goal is really fast really heavy bullets or a max of mass x velocity.
we can assume that the barrel is a fixed length, or somewhat the same.
I am attempting to understand the .270 and the .308 rounds. I have both and reload and shoot both.
the case for the .308 is smaller than the .270 so less powder.

is powder expansion rate (not defined by the specific barrel) related to burn rate or is it fixed (1grn of x powder expands 10.3 times at a faster rate than powder B that also expands 10.3 times) or maybe powder x expands to 10.3x and powder B only expands to 9.3x and takes longer) I am looking for a measure of force over time by powder. with the assumption that i can guess at the same barrel length and or bullet weight what powder will give me a higher velocity.

which brings me to the last part. the .308 has more space inside the barrel before the muzzle than the .270 so I assume I need a faster burning powder despite having more of it, to apply the same force on the .270 projectile.
but having more in a smaller space may be equal???

heres the real question: does 1gn of powder A expand to the same size as 1gn of powder B. I am looking to simplify not expand on burn rates. is it true that more powder burning longer in a smaller tube gives the same punch a less powder burning faster in a bigger tube. or is my head in a dark tunnel looking backwards.

i am currently running a test; same powder volume(full case) same bullet mass, (150) and different powder speeds. unfortunately I do not as of yet have a velocity meter so until I get one it is subjective.

some of this seems a little counter intuitive, faster powder in the .270 may be too much.
so for me the word accurate is inversely equal to the size of the group, more accurate smaller group.
best round to date was a .90 grn nosler, with imr3031 powder @200m. 3/4" group - that is one fast soag. this point may not fit my understanding. i think fast powder heavy bullet should be max impulse. but maybe fast powder light bullet equals max velocity. I look forward to hearing all about this.
 
sailnaked said:
my understandings are such
momentum(impulse) = mass X velocity,
more velocity means faster time to target and less drop at the target.
more push / velocity (accelerarion) in the barrel equals more velocity after it leaves the barrel. so in some sense more powder should equal more push.
now this is where it gets tricky:
smaller bullet will go faster if they have enough barrel and the powder burns fast enough.
heavier bullets will go faster because they get more push by the powder longer and they have more mass. (feel free to argue this but only partially what I am looking for.)
lets assume for this case that we want faster bullets and the ultimate goal is really fast really heavy bullets or a max of mass x velocity.
we can assume that the barrel is a fixed length, or somewhat the same.
I am attempting to understand the .270 and the .308 rounds. I have both and reload and shoot both.
the case for the .308 is smaller than the .270 so less powder.

is powder expansion rate (not defined by the specific barrel) related to burn rate or is it fixed (1grn of x powder expands 10.3 times at a faster rate than powder B that also expands 10.3 times) or maybe powder x expands to 10.3x and powder B only expands to 9.3x and takes longer) I am looking for a measure of force over time by powder. with the assumption that i can guess at the same barrel length and or bullet weight what powder will give me a higher velocity.

which brings me to the last part. the .308 has more space inside the barrel before the muzzle than the .270 so I assume I need a faster burning powder despite having more of it, to apply the same force on the .270 projectile.
but having more in a smaller space may be equal???

heres the real question: does 1gn of powder A expand to the same size as 1gn of powder B. I am looking to simplify not expand on burn rates. is it true that more powder burning longer in a smaller tube gives the same punch a less powder burning faster in a bigger tube. or is my head in a dark tunnel looking backwards.

i am currently running a test; same powder volume(full case) same bullet mass, (150) and different powder speeds. unfortunately I do not as of yet have a velocity meter so until I get one it is subjective.

some of this seems a little counter intuitive, faster powder in the .270 may be too much.
so for me the word accurate is inversely equal to the size of the group, more accurate smaller group.
best round to date was a .90 grn nosler, with imr3031 powder @200m. 3/4" group - that is one fast soag. this point may not fit my understanding. i think fast powder heavy bullet should be max impulse. but maybe fast powder light bullet equals max velocity. I look forward to hearing all about this.
Click to expand...
There's "burn rate", the rate at which it burns, and there's "heat of explosion energy", which is what I'd characterize as the amount of energy released during the burn. These are two different things that work together. You can't look at just one as "the" factor for determining the force produced at any point during the powder burn.

It's been too many decades since I delt with chemistry and physics. There's other's here with more knowledge and experience than I that might explain it in the details you seem to be looking for.
 
sailnaked said:
my understandings are such
momentum(impulse) = mass X velocity,
more velocity means faster time to target and less drop at the target.
more push / velocity (accelerarion) in the barrel equals more velocity after it leaves the barrel. so in some sense more powder should equal more push.
now this is where it gets tricky:
smaller bullet will go faster if they have enough barrel and the powder burns fast enough.
heavier bullets will go faster because they get more push by the powder longer and they have more mass. (feel free to argue this but only partially what I am looking for.)
lets assume for this case that we want faster bullets and the ultimate goal is really fast really heavy bullets or a max of mass x velocity.
we can assume that the barrel is a fixed length, or somewhat the same.
I am attempting to understand the .270 and the .308 rounds. I have both and reload and shoot both.
the case for the .308 is smaller than the .270 so less powder.

is powder expansion rate (not defined by the specific barrel) related to burn rate or is it fixed (1grn of x powder expands 10.3 times at a faster rate than powder B that also expands 10.3 times) or maybe powder x expands to 10.3x and powder B only expands to 9.3x and takes longer) I am looking for a measure of force over time by powder. with the assumption that i can guess at the same barrel length and or bullet weight what powder will give me a higher velocity.

which brings me to the last part. the .308 has more space inside the barrel before the muzzle than the .270 so I assume I need a faster burning powder despite having more of it, to apply the same force on the .270 projectile.
but having more in a smaller space may be equal???

heres the real question: does 1gn of powder A expand to the same size as 1gn of powder B. I am looking to simplify not expand on burn rates. is it true that more powder burning longer in a smaller tube gives the same punch a less powder burning faster in a bigger tube. or is my head in a dark tunnel looking backwards.

i am currently running a test; same powder volume(full case) same bullet mass, (150) and different powder speeds. unfortunately I do not as of yet have a velocity meter so until I get one it is subjective.

some of this seems a little counter intuitive, faster powder in the .270 may be too much.
so for me the word accurate is inversely equal to the size of the group, more accurate smaller group.
best round to date was a .90 grn nosler, with imr3031 powder @200m. 3/4" group - that is one fast soag. this point may not fit my understanding. i think fast powder heavy bullet should be max impulse. but maybe fast powder light bullet equals max velocity. I look forward to hearing all about this.
Click to expand...
You might get a better response if you used the capitol on your keyboard. Us old people need all the help we can reading a post...lol
 
I get suspicious of a brand-new account posting such a query on their first post..... but I will make a strong suggestion for their safety and then wish them well. It is my hope this isn't another troll.....

Since I can tell the OP has no physics, thermodynamics, chemistry, or ballistics background, it would be far safer for them to get hold of an internal ballistics program to play with while they read several chapters of ballistics textbooks to fill in that deficiency.

You can model propellants, bullets, barrel lengths, etc., to learn to get a feel for internal ballistics without the risk to your safety. Rookies should never attempt to do home experiments with dangerous high pressure such as found in ballistics. Good Luck. YMMV
 
sailnaked said:
my understandings are such
momentum(impulse) = mass X velocity,
more velocity means faster time to target and less drop at the target.
more push / velocity (accelerarion) in the barrel equals more velocity after it leaves the barrel. so in some sense more powder should equal more push.
now this is where it gets tricky:
smaller bullet will go faster if they have enough barrel and the powder burns fast enough.
heavier bullets will go faster because they get more push by the powder longer and they have more mass. (feel free to argue this but only partially what I am looking for.)
lets assume for this case that we want faster bullets and the ultimate goal is really fast really heavy bullets or a max of mass x velocity.
we can assume that the barrel is a fixed length, or somewhat the same.
I am attempting to understand the .270 and the .308 rounds. I have both and reload and shoot both.
the case for the .308 is smaller than the .270 so less powder.

is powder expansion rate (not defined by the specific barrel) related to burn rate or is it fixed (1grn of x powder expands 10.3 times at a faster rate than powder B that also expands 10.3 times) or maybe powder x expands to 10.3x and powder B only expands to 9.3x and takes longer) I am looking for a measure of force over time by powder. with the assumption that i can guess at the same barrel length and or bullet weight what powder will give me a higher velocity.

which brings me to the last part. the .308 has more space inside the barrel before the muzzle than the .270 so I assume I need a faster burning powder despite having more of it, to apply the same force on the .270 projectile.
but having more in a smaller space may be equal???

heres the real question: does 1gn of powder A expand to the same size as 1gn of powder B. I am looking to simplify not expand on burn rates. is it true that more powder burning longer in a smaller tube gives the same punch a less powder burning faster in a bigger tube. or is my head in a dark tunnel looking backwards.

i am currently running a test; same powder volume(full case) same bullet mass, (150) and different powder speeds. unfortunately I do not as of yet have a velocity meter so until I get one it is subjective.

some of this seems a little counter intuitive, faster powder in the .270 may be too much.
so for me the word accurate is inversely equal to the size of the group, more accurate smaller group.
best round to date was a .90 grn nosler, with imr3031 powder @200m. 3/4" group - that is one fast soag. this point may not fit my understanding. i think fast powder heavy bullet should be max impulse. but maybe fast powder light bullet equals max velocity. I look forward to hearing all about this.
Click to expand...
Sounds like OCD. Just shoot the gun.
 
RegionRat said:
I get suspicious of a brand-new account posting such a query on their first post..... but I will make a strong suggestion for their safety and then wish them well. It is my hope this isn't another troll.....

Since I can tell the OP has no physics, thermodynamics, chemistry, or ballistics background, it would be far safer for them to get hold of an internal ballistics program to play with while they read several chapters of ballistics textbooks to fill in that deficiency.

You can model propellants, bullets, barrel lengths, etc., to learn to get a feel for internal ballistics without the risk to your safety. Rookies should never attempt to do home experiments with dangerous high pressure such as found in ballistics. Good Luck. YMMV
Click to expand...
Your first sentenced summed it up perfectly
 
sailnaked said:
my understandings are such
momentum(impulse) = mass X velocity,
more velocity means faster time to target and less drop at the target.
more push / velocity (accelerarion) in the barrel equals more velocity after it leaves the barrel. so in some sense more powder should equal more push.
now this is where it gets tricky:
smaller bullet will go faster if they have enough barrel and the powder burns fast enough.
heavier bullets will go faster because they get more push by the powder longer and they have more mass. (feel free to argue this but only partially what I am looking for.)
lets assume for this case that we want faster bullets and the ultimate goal is really fast really heavy bullets or a max of mass x velocity.
we can assume that the barrel is a fixed length, or somewhat the same.
I am attempting to understand the .270 and the .308 rounds. I have both and reload and shoot both.
the case for the .308 is smaller than the .270 so less powder.

is powder expansion rate (not defined by the specific barrel) related to burn rate or is it fixed (1grn of x powder expands 10.3 times at a faster rate than powder B that also expands 10.3 times) or maybe powder x expands to 10.3x and powder B only expands to 9.3x and takes longer) I am looking for a measure of force over time by powder. with the assumption that i can guess at the same barrel length and or bullet weight what powder will give me a higher velocity.

which brings me to the last part. the .308 has more space inside the barrel before the muzzle than the .270 so I assume I need a faster burning powder despite having more of it, to apply the same force on the .270 projectile.
but having more in a smaller space may be equal???

heres the real question: does 1gn of powder A expand to the same size as 1gn of powder B. I am looking to simplify not expand on burn rates. is it true that more powder burning longer in a smaller tube gives the same punch a less powder burning faster in a bigger tube. or is my head in a dark tunnel looking backwards.

i am currently running a test; same powder volume(full case) same bullet mass, (150) and different powder speeds. unfortunately I do not as of yet have a velocity meter so until I get one it is subjective.

some of this seems a little counter intuitive, faster powder in the .270 may be too much.
so for me the word accurate is inversely equal to the size of the group, more accurate smaller group.
best round to date was a .90 grn nosler, with imr3031 powder @200m. 3/4" group - that is one fast soag. this point may not fit my understanding. i think fast powder heavy bullet should be max impulse. but maybe fast powder light bullet equals max velocity. I look forward to hearing all about this.
Click to expand...
Yes, expansion area affects powder burn/pressures. Think of the chamber plus say 3" down the bore.

Also, there's the area of force on the back of the bullet. Think hydraulics. Larger bore cyl equals more force at equal pressure.
 
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