duncan61 wrote:Its the spin imparted by the rifling that causes the projectile to go down when leaving the barrel then rise up past the line of sight then start to drop at about 100 cos of gravity.Remember this little pill is pissbolting along its not a lawn dart.From memory the SLR in7.62 was .5 inch low at 26 yards 1.5 inch high at 100 yards spot on at 200 yards and 1.5 low at 300 yards as you are shooting man size targets it really doesnt matter
My 168gr sierra target bullets shoot higher at 100m than my 100 grain hunting bullets possibly because they are nearly twice as long and have more purchase on the rifling and spin more plus the meplat and ogive would come into play and they are going a lot slower at 2800fps compared to the 100gr at 3300fps.I have never shot the 100gr at 900m but doubt they would make it.I am nearly maxed on the scope with the target bullets that fly like bigass spears
duncan61 wrote:I am assuming all rifling goes clockwise.Has anyone heard of rifling going anticlockwise
duncan61 wrote:Life is full of little mysteries like the world is not round but slightly oval because its liquid and spinning.If a satellite has a low orbit a compensation has to be made when it flies over the equator if its 40,000 kms out it does not matter.If the polar seas melt the water will go down 33 ft.We are heading for another ice age man is holding it off with global warming.The Amazon rainforest is bigger now than in the 70s that stuff grows hard.For some reason people get hold of things that are not true without checking it out for themselves.I believe what I believe because I research it till I am satisfied.The spin imparted on a high speed projectile makes it dip on leaving the barrel then rise before dipping again.Old stuff like 45/70 may not do this and on my .222 Its hardly measurable as I run 2208 which is very slow for a 50gr PSP but I have a lot of it and it gives me 2800fps with 22.2 gr which is perfect for head shooting roos and foxes
duncan61 wrote:Its the spin imparted by the rifling that causes the projectile to go down when leaving the barrel then rise up past the line of sight then start to drop at about 100 cos of gravity.Remember this little pill is pissbolting along its not a lawn dart.From memory the SLR in7.62 was .5 inch low at 26 yards 1.5 inch high at 100 yards spot on at 200 yards and 1.5 low at 300 yards as you are shooting man size targets it really doesnt matter
My 168gr sierra target bullets shoot higher at 100m than my 100 grain hunting bullets possibly because they are nearly twice as long and have more purchase on the rifling and spin more plus the meplat and ogive would come into play and they are going a lot slower at 2800fps compared to the 100gr at 3300fps.I have never shot the 100gr at 900m but doubt they would make it.I am nearly maxed on the scope with the target bullets that fly like bigass spears
sandgroperbill wrote:Now...
Sound moderators...
straightshooter wrote:Supaduke wrote:Wife: another rifle? How much was that one?
Me: on special, only $300
Wrong Wrong Wrong Wrong Wrong!
The right answer is either
a) Honey, I've owned that rifle since before we were married. Is that how much interest you take in my hobby?
b) I sold another rifle to buy this one.
'On special' only kinda works for shoes and handbags.
brett1868 wrote:duncan61 wrote:Life is full of little mysteries like the world is not round but slightly oval because its liquid and spinning.If a satellite has a low orbit a compensation has to be made when it flies over the equator if its 40,000 kms out it does not matter.If the polar seas melt the water will go down 33 ft.We are heading for another ice age man is holding it off with global warming.The Amazon rainforest is bigger now than in the 70s that stuff grows hard.For some reason people get hold of things that are not true without checking it out for themselves.I believe what I believe because I research it till I am satisfied.The spin imparted on a high speed projectile makes it dip on leaving the barrel then rise before dipping again.Old stuff like 45/70 may not do this and on my .222 Its hardly measurable as I run 2208 which is very slow for a 50gr PSP but I have a lot of it and it gives me 2800fps with 22.2 gr which is perfect for head shooting roos and foxes
That effect of the projectile is known as the Magnus effect but deemed so insignificant that few if any ballistics programs allow for it. External Ballistics is fairly well covered in Bryan Litz's book "Applied Ballistics for long range shooting", Not a bad read if you have the time.
brett1868 wrote:Myth - Bullets "Rise" after leaving the barrel.
Fact - They only rise if the barrel is angled up. If the barrel is parallel to the surface, the laws of physics prevent the projectile from rising.
<<Genesis93>> wrote:brett1868 wrote:Myth - Bullets "Rise" after leaving the barrel.
Fact - They only rise if the barrel is angled up. If the barrel is parallel to the surface, the laws of physics prevent the projectile from rising.
I think this might get interesting.....
I'll have to find the postings re curvature of the earth....
Complicating the matter would be that the earth curves, so the bullet, traveling in a straight line perpendicular to the centre of the earth would actually 'rise' if the bullet 'drop' was less than the curvature of the earth... my head is starting to hurt, but here goes;
Distant - curvature of earth
100m - 1mm
200m - 3mm
500m - 20mm
750m - 44mm
1000m - 79mm
1250m - 123mm
1500m - 177mm
2000m - 314mm
So... 'technically' if your projectile is launched with enough voom... that the drop at 1000m is LESS than 79mm then it would RISE relative to the earth....
But yes.... as soon as any projectile is released, the one primary force acting on it would be gravity, accelerating the mass toward the centre of the earth....
'Rise', other than the above curvature/drop defeating, would be casue by AERODYNAMIC effects, say if the nose is up relative to the direction of travel and the uplift counters the drop, partially......like the wing of a plane, NOT gravity defeating 'magic'...
sandgroperbill wrote:Gun goes "bang"
Animal goes "flop"
'Nuf said.
sandgroperbill wrote:Gun goes "bang"
Animal goes "flop"
'Nuf said.
duncan61 wrote:I am assuming all rifling goes clockwise.Has anyone heard of rifling going anticlockwise
sandgroperbill wrote:Remove friction and gravity is the same, all else being equal.
Which weighs more? A tonne of feathers or a tonne of bowling balls.
BRNO_Bigot wrote:duncan61 wrote:I am assuming all rifling goes clockwise.Has anyone heard of rifling going anticlockwise
Colt 1911 for one. Just Google "1911 rifling", which is what I did to make absolutely sure I wasn't the only person in the world who had an anti-clockwise barrel.
sandgroperbill wrote:Different scales, troy...
Title_II wrote:9mm is .45 set to stun. And real men don't stun
http://www.michaelzwilliamson.com/polit ... earms.html
^take a quick look at that, if you've never seen it, it is very entertaining and funny
brett1868 wrote:sandgroperbill wrote:Gun goes "bang"
Animal goes "flop"
'Nuf said.
Are you related to Bigfellascott ? He's the master of practical shooting, same or better results as anyone else with 1/10 the technical BS.
Shooting due east vrs due west will have different drops at 1000m and again different depending on latitude. By the time I've done the math Scott's shot, skinned, cooked and devoured the intended target.
Here's a question for the punters, if I was to drop a feather and a bowling ball in a vacuum which would hit the ground first?
tlia7 wrote:Weirdest story ever told to me was back in the 70's but an old timer who has since gone to God. He was on a hunting trip with a bunch of guys and camped out in the evening and one guy started to tell them that if you put your thumb over the barrel of a 22 really tight and pull the trigger the vacuum will stop the bullet. They all said bulls**t but he insisted and began to show them..... I asked What happened? the old timer said the d**khead shot his thumb off.