NastyDaddy101
New member
I would agree with harmonics,bullets don't rise,gravity starts as soon as they leave the barrel.
Interesting find at the range today....
- Thread starter Hidalgo
- Start date
CalCoyote
New member
I have absolutely nothing to add to this thread in the way knowledge.
BUT
I sure do learn a lot by reading threads like this.
Sometimes I think I can learn more on this forum than if I had taken a college class. With regard to the physics of reloading: Some of you guys have developed specialized knowledge over the years and are college professors and don't even know it.
And the best thing about it is that I don't have to pay tuition. /ubbthreads/images/graemlins/ooo.gif /ubbthreads/images/graemlins/ooo.gif /ubbthreads/images/graemlins/ooo.gif
BUT
I sure do learn a lot by reading threads like this.
Sometimes I think I can learn more on this forum than if I had taken a college class. With regard to the physics of reloading: Some of you guys have developed specialized knowledge over the years and are college professors and don't even know it.
And the best thing about it is that I don't have to pay tuition. /ubbthreads/images/graemlins/ooo.gif /ubbthreads/images/graemlins/ooo.gif /ubbthreads/images/graemlins/ooo.gif
Hidalgo
Well-known member
Quote:
I have absolutely nothing to add to this thread in the way knowledge.
BUT
I sure do learn a lot by reading threads like this.
THAT'S the reason I spend time on here. /ubbthreads/images/graemlins/grinning-smiley-003.gif
...........sometimes, way too MUCH time. /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/wink.gif
I have absolutely nothing to add to this thread in the way knowledge.
BUT
I sure do learn a lot by reading threads like this.
THAT'S the reason I spend time on here. /ubbthreads/images/graemlins/grinning-smiley-003.gif
...........sometimes, way too MUCH time. /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/wink.gif
Hidalgo
Well-known member
Quote:
I would agree with harmonics,bullets don't rise,gravity starts as soon as they leave the barrel.
Then, taking that piece of information into consideration, (which I totally agree with) wouldn't it be appropriate to deduct that the Noslers are traveling faster than the VMaxs?
.......I gotta take the chrony with me next trip. /ubbthreads/images/graemlins/crazy.gif /ubbthreads/images/graemlins/wink.gif
EDIT TO ADD: I just checked the ballistics for the two loads in question. After looking at 3 different sets of data for the VMax, and 2 different ones for the Nosler, it seems that the Nosler is traveling at 3048, and the VMax is running 2850 (I chronographed this load and it's actually 2835 from my rifle). That's a velocity diff of 200fps. That in itself could cause the jump in POI. Also, the BC is .265 for the VMax, and .270 for the Nosler. Miniscule, but also could add to the difference.
I still find it amazing that simple things like BC, base configuration, and bearing surface could cause changes of that much without changing any other components.
I would agree with harmonics,bullets don't rise,gravity starts as soon as they leave the barrel.
Then, taking that piece of information into consideration, (which I totally agree with) wouldn't it be appropriate to deduct that the Noslers are traveling faster than the VMaxs?
.......I gotta take the chrony with me next trip. /ubbthreads/images/graemlins/crazy.gif /ubbthreads/images/graemlins/wink.gif
EDIT TO ADD: I just checked the ballistics for the two loads in question. After looking at 3 different sets of data for the VMax, and 2 different ones for the Nosler, it seems that the Nosler is traveling at 3048, and the VMax is running 2850 (I chronographed this load and it's actually 2835 from my rifle). That's a velocity diff of 200fps. That in itself could cause the jump in POI. Also, the BC is .265 for the VMax, and .270 for the Nosler. Miniscule, but also could add to the difference.
I still find it amazing that simple things like BC, base configuration, and bearing surface could cause changes of that much without changing any other components.
Last edited:
The Perferator
New member
I'm going with the harmonics theory. What length and type of barrel do you have? Is it a lighter contour barrel? It seems that barrel would be more sensitive to pressure wave harmonics.
Is it a varmint type barrel? If that is the case it might be another reason for the jump in POI.
Other than that I just say the heck with it since it shoots so good for you.
Is it a varmint type barrel? If that is the case it might be another reason for the jump in POI.
Other than that I just say the heck with it since it shoots so good for you.
bigwheeler
New member
one bullet drops 1.7 and the other 2.1 at those speeds, how do you get a 2
inch spread from that. It's harmonics. Most guns print different with different
loads. The fact that the bullet is traveling faster means it exits the barrel under
a different tune as been stated before. Google barrel harmonics and do some
reading. This is a well researched part of loading. here is a link to teach you how to get very close to your most accurate load before you leave the computer. http://www.clik.to/optimalchargeweight
inch spread from that. It's harmonics. Most guns print different with different
loads. The fact that the bullet is traveling faster means it exits the barrel under
a different tune as been stated before. Google barrel harmonics and do some
reading. This is a well researched part of loading. here is a link to teach you how to get very close to your most accurate load before you leave the computer. http://www.clik.to/optimalchargeweight
Mrgunslinger
New member
Ditto on what sdb777 said !
Same everything but more bearing surface which makes the partition have a lower volicity thus striking high.
WHY !
Even though it is a 223 it still recoils and the recoil with the nosler partiton the barrel will raise higher before the bullet exits the bore.
Plain fact as to what is happening here.
A crony will prove it.
Same everything but more bearing surface which makes the partition have a lower volicity thus striking high.
WHY !
Even though it is a 223 it still recoils and the recoil with the nosler partiton the barrel will raise higher before the bullet exits the bore.
Plain fact as to what is happening here.
A crony will prove it.
clayman90
New member
Quote:
Ditto on what sdb777 said !
Same everything but more bearing surface which makes the partition have a lower volicity thus striking high.
WHY !
Even though it is a 223 it still recoils and the recoil with the nosler partiton the barrel will raise higher before the bullet exits the bore.
Plain fact as to what is happening here.
A crony will prove it.
A bullet with a longer bearing surface will allow pressures to build which will enable a higher velocity, not lower velocity.
Any time you change bullets in the fashion the original poster did, you cannot guess the results. He has simply found that by changing bullets that the new bullet impacts the target 2" above the previous, all things being the same.
I am running 80gr Berger's, 85gr TSX's, and 87gr VMaxs all with the same charge of Ramshot Hunter powder.
Am taking them out to 500M tomorrow to see how they fly with each other at longer ranges.
At 100yds, they will place a 3/4" 9 shot group, 3 of each bullet.
Have my hopes up, but time will tell.
Clayman
Ditto on what sdb777 said !
Same everything but more bearing surface which makes the partition have a lower volicity thus striking high.
WHY !
Even though it is a 223 it still recoils and the recoil with the nosler partiton the barrel will raise higher before the bullet exits the bore.
Plain fact as to what is happening here.
A crony will prove it.
A bullet with a longer bearing surface will allow pressures to build which will enable a higher velocity, not lower velocity.
Any time you change bullets in the fashion the original poster did, you cannot guess the results. He has simply found that by changing bullets that the new bullet impacts the target 2" above the previous, all things being the same.
I am running 80gr Berger's, 85gr TSX's, and 87gr VMaxs all with the same charge of Ramshot Hunter powder.
Am taking them out to 500M tomorrow to see how they fly with each other at longer ranges.
At 100yds, they will place a 3/4" 9 shot group, 3 of each bullet.
Have my hopes up, but time will tell.
Clayman
bigwheeler
New member
You'll have fun figuring recoil and speed into a sideways change in poi instead
of up or down.
of up or down.
I'm going with the harmonics idea, but it is a good reason to buy a chrony. Is there a bad reson to buy a chrony? The chrony will tell you that they are about the same velocity but because of the longer bearing surface on the Nosler it has a differant harmonics and therefore leaves the barrel on what sounds like an up swing. If you put your ear right up to the barrel while someone fires it you will hear the high pitched ringing sound of the harmonics
Hidalgo
Well-known member
Quote:
I think Catshooter could answer this question. I have been watching him and he seems to be pretty knowledgable about guns! I am surprised he hasnt replied yet. Must be occupied.
Naw....Shooter just doesn't like me anymore. /ubbthreads/images/graemlins/frown.gif
What makes you think he's knowledgeable about guns? /ubbthreads/images/graemlins/confused1.gif /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/wink.gif
I think Catshooter could answer this question. I have been watching him and he seems to be pretty knowledgable about guns! I am surprised he hasnt replied yet. Must be occupied.
Naw....Shooter just doesn't like me anymore. /ubbthreads/images/graemlins/frown.gif
What makes you think he's knowledgeable about guns? /ubbthreads/images/graemlins/confused1.gif /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/wink.gif
CatShooter
New member
Quote:
I think Catshooter could answer this question. I have been watching him and he seems to be pretty knowledgable about guns! I am surprised he hasnt replied yet. Must be occupied.
You expect me to jump into this mess - my momma didn't raise no fool.
Anyway... I don't like Higgy anymore /ubbthreads/images/graemlins/smile.gif /ubbthreads/images/graemlins/smile.gif /ubbthreads/images/graemlins/smile.gif
OK...it has nothing to do with ogives, or surface bearing or pressure, or increase in velocity or nuttin'...
In light or standard weight barrels it is not unusual for different bullets (even the same weight) to have very different POI's. Sometimes it is above, like in this case, and that invites all kinds or "theories" (like in this case)... but what do you say when it is 2"" to the left or to the right? - those "theories" go up in smoke
The amount that a gun moves during recoil before the bullet leaves the barrel is just a few thousandths of an inch - and AR's move straight back back because of the angle of stock attachment. And and since the bullet weights are the same, then the time in the barrel is ~the same, so that doesn't cut it.
For any "theory" to be valid, it must do the same thing all the time... and you will find that when you change bullets, they can go in the same POI, or they can go high, low, or to the side...
... and I still don't like Higgy anymore /ubbthreads/images/graemlins/wink.gif /ubbthreads/images/graemlins/wink.gif /ubbthreads/images/graemlins/wink.gif
.
I think Catshooter could answer this question. I have been watching him and he seems to be pretty knowledgable about guns! I am surprised he hasnt replied yet. Must be occupied.
You expect me to jump into this mess - my momma didn't raise no fool.
Anyway... I don't like Higgy anymore /ubbthreads/images/graemlins/smile.gif /ubbthreads/images/graemlins/smile.gif /ubbthreads/images/graemlins/smile.gif
OK...it has nothing to do with ogives, or surface bearing or pressure, or increase in velocity or nuttin'...
In light or standard weight barrels it is not unusual for different bullets (even the same weight) to have very different POI's. Sometimes it is above, like in this case, and that invites all kinds or "theories" (like in this case)... but what do you say when it is 2"" to the left or to the right? - those "theories" go up in smoke
The amount that a gun moves during recoil before the bullet leaves the barrel is just a few thousandths of an inch - and AR's move straight back back because of the angle of stock attachment. And and since the bullet weights are the same, then the time in the barrel is ~the same, so that doesn't cut it.
For any "theory" to be valid, it must do the same thing all the time... and you will find that when you change bullets, they can go in the same POI, or they can go high, low, or to the side...
... and I still don't like Higgy anymore /ubbthreads/images/graemlins/wink.gif /ubbthreads/images/graemlins/wink.gif /ubbthreads/images/graemlins/wink.gif
.
ironworker
New member
No shortage of opinions . Bottom line hunt with what your rifle is sighted in for. Hopefully the weather conditions will be the same where you hunt.
Evil_Lurker
New member
I've shot around 5 different 55 gr. loads in my 20" .223 SUM and they all shoot to the same POI except the factory Hornady V Max's. They shoot a tiny group (the best of the bunch) about 1 1/2" low and right at 100. It's something weird with the V Max's because I can duplicate it over and over.
It's been mentiond on the forum before, and several other people were seeing the same thing.
Quote:
If you put your ear right up to the barrel while someone fires it you will hear the high pitched ringing sound of the harmonics
Heh..heh, that may be true, but I'm going to give that experiment a pass. /ubbthreads/images/graemlins/crazy.gif
Low and right tells me it's barrel harmonics causing it.
It's been mentiond on the forum before, and several other people were seeing the same thing.
Quote:
If you put your ear right up to the barrel while someone fires it you will hear the high pitched ringing sound of the harmonics
Heh..heh, that may be true, but I'm going to give that experiment a pass. /ubbthreads/images/graemlins/crazy.gif
Low and right tells me it's barrel harmonics causing it.
jacket thickness differences as well as different harmonics. The barrel vibrates in the shape of the infinty symbol. the best groups are acheived when the bullet exits the muzzle at the intersection, however, a bullet/load may exit the muzzle at a different point, but do it consistently at the same point, and will show accuracy as well.
Jacket thickness coupled with a different "dwell" time than the v-max.
my .002"
Jacket thickness coupled with a different "dwell" time than the v-max.
my .002"
CatShooter
New member
Quote:
jacket thickness differences as well as different harmonics. The barrel vibrates in the shape of the infinty symbol. the best groups are acheived when the bullet exits the muzzle at the intersection, however, a bullet/load may exit the muzzle at a different point, but do it consistently at the same point, and will show accuracy as well.
Jacket thickness coupled with a different "dwell" time than the v-max.
my .002"
Jacket thickness has no "bearing"( /ubbthreads/images/graemlins/smile.gif )on this. Where does this crap come from??
The vibrations in a barrel ("IF" it has them) do not form an infinity pattern - they are random, and they vary with different barrels, and are so slow that they cannot complete a single cycle before the bullet leaves the muzzle.
The "resonant frequency" of a barrel is only a hundred or so whips per second - the "dwell time" in the barrel of a high speed bullet is 1.5 to 2 milliseconds. So a "Dwell cycle" takes 10 milliseconds, the bullet is gone in 1/5th of a single cycle - in other words - if the barrel "is" harmonically vibration, the bullet is gone before 1/5th of the first cycle has started...
... do the math yourself!
.
jacket thickness differences as well as different harmonics. The barrel vibrates in the shape of the infinty symbol. the best groups are acheived when the bullet exits the muzzle at the intersection, however, a bullet/load may exit the muzzle at a different point, but do it consistently at the same point, and will show accuracy as well.
Jacket thickness coupled with a different "dwell" time than the v-max.
my .002"
Jacket thickness has no "bearing"( /ubbthreads/images/graemlins/smile.gif )on this. Where does this crap come from??
The vibrations in a barrel ("IF" it has them) do not form an infinity pattern - they are random, and they vary with different barrels, and are so slow that they cannot complete a single cycle before the bullet leaves the muzzle.
The "resonant frequency" of a barrel is only a hundred or so whips per second - the "dwell time" in the barrel of a high speed bullet is 1.5 to 2 milliseconds. So a "Dwell cycle" takes 10 milliseconds, the bullet is gone in 1/5th of a single cycle - in other words - if the barrel "is" harmonically vibration, the bullet is gone before 1/5th of the first cycle has started...
... do the math yourself!
.
MPFD
Active member
Quote:
It's also slower and spends a little more time traveling down the barrel. More barrel time means the muzzle is a little higher by the time it exits.
I don't agree with this. There is not any significant recoil un till the bullet leaves the barrel. Recoil in it's self is the equal and opposite reaction from the force caused when the gasses are aloud to escape from the muzzle. I may be wrong, but there should not be much more recoil then what is created by the primer pop till the bullet is clear of the muzzle.
It's also slower and spends a little more time traveling down the barrel. More barrel time means the muzzle is a little higher by the time it exits.
I don't agree with this. There is not any significant recoil un till the bullet leaves the barrel. Recoil in it's self is the equal and opposite reaction from the force caused when the gasses are aloud to escape from the muzzle. I may be wrong, but there should not be much more recoil then what is created by the primer pop till the bullet is clear of the muzzle.
CatShooter
New member
Quote:
Quote:
It's also slower and spends a little more time traveling down the barrel. More barrel time means the muzzle is a little higher by the time it exits.
I don't agree with this. There is not any significant recoil until the bullet leaves the barrel. Recoil in itself is the equal and opposite reaction from the force caused when the gasses are allowed to escape from the muzzle. I may be wrong, but there should not be much more recoil then what is created by the primer pop till the bullet is clear of the muzzle.
I agree with your disagreement.
If you do the math, the rifle has moved only a few thou when the bullet clears the muzzle - the bulk of the recoil is after the bullet is gone.
The recoil is equal to the sum of the momentum of the bullet's velocity times it's weight, plus the weight of the powder times the exit velocity of the gas (~5,000 fps)... when you get the total forward momentum, you take the weight of the rifle, and work backwards.
If the recoil was well on its way before the bullet left, then muzzle breaks wouldn't be able to work.
.
Quote:
It's also slower and spends a little more time traveling down the barrel. More barrel time means the muzzle is a little higher by the time it exits.
I don't agree with this. There is not any significant recoil until the bullet leaves the barrel. Recoil in itself is the equal and opposite reaction from the force caused when the gasses are allowed to escape from the muzzle. I may be wrong, but there should not be much more recoil then what is created by the primer pop till the bullet is clear of the muzzle.
I agree with your disagreement.
If you do the math, the rifle has moved only a few thou when the bullet clears the muzzle - the bulk of the recoil is after the bullet is gone.
The recoil is equal to the sum of the momentum of the bullet's velocity times it's weight, plus the weight of the powder times the exit velocity of the gas (~5,000 fps)... when you get the total forward momentum, you take the weight of the rifle, and work backwards.
If the recoil was well on its way before the bullet left, then muzzle breaks wouldn't be able to work.
.