muzzle velocity vs accuracy
#21
Big Z
I do not think velocity has anything to do with RPM's that is set in the bore and decays as the bullet travels.... however, velocity will the get the bullet a greater distance before the RPM's decay to instability
I think!
the higher velocity will give greater RPMs and therefore deterioration would obviously take longer..
I think!
#22
Boone & Crockett
Join Date: Apr 2007
Location: River Ridge, LA (Suburb of New Orleans)
Posts: 10,918
I do not think velocity has anything to do with RPM's that is set in the bore
Let's slow everything down. If you shoot a bullet out of a 1:36 twist bore at a velocity of three feet per second, the bullet would travel three feet in a second and revolve once during that second (i.e. 60 RPMs). Now shoot that bullet out of the same bore at 6 feet per second the bullet would travel six feet in a second and revolve twice during that second (120 RPMs). It's still rotating one time for every thirty-six inches traveled, but it's traveling twice as far in one second, so higher velocity means higher RPMs - but still one revolution per 36 inches traveled.
#23
Semi
I thinking....
I did think... i really tried
I'll read this again tomorrow... I am baby sitting my 2 1/2 year old grand daughter all by myself - I am not thinking well when it comes to high math...
I thinking....
I did think... i really tried
I'll read this again tomorrow... I am baby sitting my 2 1/2 year old grand daughter all by myself - I am not thinking well when it comes to high math...
Last edited by sabotloader; 03-16-2010 at 08:37 PM.
#24
Boone & Crockett
Join Date: Apr 2007
Location: River Ridge, LA (Suburb of New Orleans)
Posts: 10,918
OK Grandpa. We don't want to distract you from the important stuff.
My youngest granddaughter is seven and her sister is twelve. Delightful ages also, but I wish I could start them over at two again. The twelve year old starred in Samantha's First Turkey (LINK: http://huntingnet.com/forum/black-po...st-turkey.html) What fun they are.
My youngest granddaughter is seven and her sister is twelve. Delightful ages also, but I wish I could start them over at two again. The twelve year old starred in Samantha's First Turkey (LINK: http://huntingnet.com/forum/black-po...st-turkey.html) What fun they are.
Last edited by Semisane; 03-16-2010 at 09:03 PM.
#25
Semi
OK it is new day, the diaper is changed she is dressed and playing in the living room, later we are headed to 'Frog Pond' play area in the mall...
but! I think i have it now... RPM does increase with velocity over a given distance and ROT 'rate of turn in a distance' is set by the twist of the bore - am I getting warm???
OK it is new day, the diaper is changed she is dressed and playing in the living room, later we are headed to 'Frog Pond' play area in the mall...
but! I think i have it now... RPM does increase with velocity over a given distance and ROT 'rate of turn in a distance' is set by the twist of the bore - am I getting warm???
#26
Nontypical Buck
Join Date: Mar 2004
Posts: 2,445
Semi
The way I look at it, the only thing making a bullet spin is the influence of the rifling. Once outside the bore, that influence is eliminated and spin can only diminish. Once started spinning, the bullet does not "want" to spin faster or even keep spinning at all. The RPM and rotation per inch decrease as the bullet travels downrange.
The way I look at it, the only thing making a bullet spin is the influence of the rifling. Once outside the bore, that influence is eliminated and spin can only diminish. Once started spinning, the bullet does not "want" to spin faster or even keep spinning at all. The RPM and rotation per inch decrease as the bullet travels downrange.
#27
Boone & Crockett
Join Date: Apr 2007
Location: River Ridge, LA (Suburb of New Orleans)
Posts: 10,918
The RPM and rotation per inch decrease as the bullet travels downrange.
#28
Giant Nontypical
Join Date: Nov 2005
Posts: 6,585
lemoyne
But, Lee I think that goes right back to your shooting background... when you were shooting bench competition were you shooting for velocity or accuracy? I believe greater accuracy (consistently) can be had with a reduced load from what you might use hunting...
But, Lee I think that goes right back to your shooting background... when you were shooting bench competition were you shooting for velocity or accuracy? I believe greater accuracy (consistently) can be had with a reduced load from what you might use hunting...
I give you the example of my 2400fps load with the Lehigh 200gr 40 caliber bullet shooting 1/2 to 3/4 inch groups when I am shooting good. The length of the bullet and the twist of the barrel and the whip of the barrel control accuracy as long as the velocity allows all to match up. Take the cartridge guns that shoot 4400 FPS and put all the bullets in one hole as an example if speed caused inaccuracy that could not work.
Also the speed of rotation has been checked with marked bullets and high speed cameras the speed of rotation slows very little after the bullet leaves the barrel, and as for it speeding up after it leaves the barrel thats a fairy tale.
#29
Typical Buck
Join Date: Jan 2007
Location: Long Island, NY
Posts: 552
OK Grandpa. We don't want to distract you from the important stuff.
My youngest granddaughter is seven and her sister is twelve. Delightful ages also, but I wish I could start them over at two again. The twelve year old starred in Samantha's First Turkey (LINK: http://huntingnet.com/forum/black-po...st-turkey.html) What fun they are.
My youngest granddaughter is seven and her sister is twelve. Delightful ages also, but I wish I could start them over at two again. The twelve year old starred in Samantha's First Turkey (LINK: http://huntingnet.com/forum/black-po...st-turkey.html) What fun they are.
What is the RPm of the younger granddaughter when she is on her sit & spin?
Does an object in motion tend to stay in motion unless acted on by another force? Just askin'!