casette shifting, again

On 12/15/2018 9:58 PM, John B. Slocomb wrote:
On Sat, 15 Dec 2018 21:39:19 -0800 (PST), Sir Ridesalot
wrote:

On Saturday, December 15, 2018 at 10:43:29 PM UTC-5, John B. Slocomb wrote:
On Sat, 15 Dec 2018 16:20:42 -0800 (PST), jbeattie
wrote:

On Saturday, December 15, 2018 at 1:59:24 PM UTC-8, AMuzi wrote:
On 12/15/2018 3:04 PM, Emanuel Berg wrote:
Frank Krygowski wrote:

Emanuel, with all due respect, you should
spend the winter reading a physics book or
two. Or three. Skip the parts on electricity,
atomic physics, etc. Concentrate on forces,
motion, work, energy etc. - the parts that
apply to bicycles. [...]

Blah blah blah, you have told me this at least
a dozen times by now. Probably because it is
easier to be didactic/demeaning than to
actually answer the questions.


more.

I left school without having slept through even one physics
class. My reference work here is a 1955 high school textbook
for $1 (9 Kr). I don't know all of even that, but I
understand the world well enough to know that this headline
last week:

https://www.dailymail.co.uk/sciencet...soon-2022.html

was completely ridiculous. The chamber pressures are in the
same range, but not power, not even within a magnitude*!
Power is work over time. Without some grasp of the actual
world, you would not have laughed aloud when reading the
headline, etc.

*A typical 120mm tank round is 7.5 kilos of depleted uranium
moving at 1700 m/s. The new 6.8 rifle typically moves 7.5
grams at 850 m/s. That's why you need basic physics.

BTW, here's an interesting case that crossed my desk: https://www.bendbulletin.com/localst...killed-in-tank https://www.oregonlive.com/pacific-n...explosion.html Interesting object lesson for re-loaders. I'm representing a party on a collateral insurance issue. I've represented a couple big gun makers in over-pressure cases. Reloads. Too much powder or the wrong powder can blow-up guns large and small.

-- Jay Beattie.

One of the things I notices in the reference was that the gun had been
"de-militarized" and that "was restored by Preston to working order".
The term "de-militarized", at least as used by the U.S.A.F., means
that the weapon is modified to a point that it cannot be fired, and
cannot be repaired. In small arms usually by cutting the receiver and
barrel into at least two parts, usually with a cutting torch.

cheers,

John B.

I read the Preston put in 8oz. more powder than was the recommended load and was told that if he fired that cartridge it'd blow up the gun. Preston was also persuaded to take out more insurance due to that overloaded cartridge.


Yes, I read that part too. I used to hand load for varmint rifles and
of course we were always trying for that little extra speed, but we
were also careful to inspect cartridge cases for signs of over
pressure. I simply can't imagine anyone just shoveling in 8 ounces of
extra powder. Particularly after someone "in the business" told not
to.

That extra 8 ounces blew my mind also.

When I was maybe 30, I was helping my dad, a long-time pistol round
reloader, mostly out of [my] curiosity. There was another seasoned
reloader there also. I measured one shell's worth of powder and was
surprised how excited they both got, exhorting me to avoid compressing
or tamping down the powder ?while scooping? (details and wording are
foggy years later). I was warned that any hint of ?compression? in the
powder could result in a overload that could destroy a pistol.

Who'd think you'd need to be careful working with explosives?

Mark J.

On Sunday, December 16, 2018 at 9:37:36 AM UTC-8, Frank Krygowski wrote:
On 12/15/2018 9:55 PM, Emanuel Berg wrote:
John B. Slocomb wrote:

In fact, this has nothing to do with any of
this. This is the bike culture which for
whatever insane reason is snobbish
beyond belief.

Hardly snobbish.

Not snobbish? Shave your legs? Remove your
helmet immediately after stepping of the bike?
If you don't, you are an embarrassment to
the sport?

Emaneul, you're shifting the discussion deep into your own imagination.
We're suggesting you gain enough fundamental knowledge to frame your
questions so we can understand them. Nobody has told you to shave your
legs or remove your helmet.

FWIW, I have never shaved my legs. I almost never wear a helmet. Get a grip!

--
- Frank Krygowski

What you have shown is that most of you on this group are both incompetent and an embarrassment to it altogether. This is the TECH group. It you can't answer a question get the hell off of it stupid.

On Sunday, December 16, 2018 at 11:04:43 AM UTC-8, Ralph Barone wrote:
wrote:
On Sunday, December 16, 2018 at 8:54:50 AM UTC-8, AMuzi wrote:

Well, John, customers of our s who are 'retired' get
amazingly lucrative offers to rework/rewrite COBOL systems.
Some of the 'obsolete' languages are critically
undersupported and in the case of major bank mainframes,
irreplaceable.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

Well, living in the land of Silicon Valley and working with major
companies and research facilities I have never even once saw anyone
looking for anyone to maintain obsolete programming languages but to write all new code.

If I owned a major corporation with a billing system consisting of a half-
million lines of COBOL and needed to add an "e-mail address" field to my
printed invoices, you can bet your ass I'd be looking for a retired COBOL
programmer instead of rewriting the system from scratch in the language du
jour.

I don't disagree with your choice. I wrote in most languages up to Python and C++. But companies don't want to fix things - they want all knew "maintainable" code. It's pretty ridiculous.

On Sunday, December 16, 2018 at 4:28:41 PM UTC-8, John B. Slocomb wrote:
Invented the method, some 270 years ago :-)

But you can't ignore air resistance. Given that most firearm's
projectiles are supersonic ( 1,125 ft/s ) air resistance is very
significant.

I see those two statements don't even ring a bell with you.

On Sunday, December 16, 2018 at 8:16:43 PM UTC-8, James wrote:
On 17/12/18 1:57 pm, John B. Slocomb wrote:
On Sun, 16 Dec 2018 21:15:00 -0500, Frank Krygowski
wrote:

On 12/16/2018 7:28 PM, John B. Slocomb wrote:


You are ignoring the effect of air resistance which means that the
speed of the projectile decreases with time during it's flight. And,
as the decrease in velocity results in an effective decrease in air
resistance the velocity decrease is not linier from muzzle to target.
For example, taken from a radar generated ballistics table a test
projectile fired at an initial velocity of 2,723 ft/s drops to 2,332
at 300 m, 1981 at 600, 1663 at 900, and 1384 at 1200. The decrease in
velocity and therefore the decrease in drag is 391 ft/s at 300 M, 351
from 300 to 600, 318 from 600 - 900 and 279 from 900 - 1200.

Yep. It's far from simple. If it were, lots more people would be good shots.

:-) Being a good shot has very little or nothing to do with
ballistics :-) More with having a good sight picture, steady hold and
good trigger squeeze :-)


In addition, I've always found that estimating the distance to a target
is rather critical. Oh, and the wind and how far from aiming generally
horizontal.

--
JS

A friend is a retired NCIS agent - actually a major team leader, that had to qualify on the range at least once a year and would use the range once a week. It was his life at risk.

When I visited him down in Phoenix he took me to a sporting goods shop that had an upstairs room with those laser targets. I took a shot or two discovering that I can no longer hold on a target. The targets were moving and jumped out at you. So I would shoot in passing. He got about a 30 out of 50 and I got 48. At one time I could shoot a flipped quarter with an M1A1. Not to say I could dead center it but leave a mark on it somewhere. That would be about 10 feet away and about 50% of the time. I told my friend I could do that and he didn't believe me. Until that range. I told him I used to play in bands and he didn't believe me and he was looking around my house one time and saw an old broken down acoustic guitar and said, "Let me hear you play it." So I ripped off "Any Way You Want To Go" complete with bridge before he ran for cover.

On Sunday, December 16, 2018 at 10:21:02 PM UTC-8, John B. Slocomb wrote:
On Sun, 16 Dec 2018 22:59:23 -0500, Frank Krygowski
wrote:

On 12/16/2018 9:57 PM, John B. Slocomb wrote:
On Sun, 16 Dec 2018 21:15:00 -0500, Frank Krygowski
wrote:

On 12/16/2018 7:28 PM, John B. Slocomb wrote:


You are ignoring the effect of air resistance which means that the
speed of the projectile decreases with time during it's flight. And,
as the decrease in velocity results in an effective decrease in air
resistance the velocity decrease is not linier from muzzle to target.
For example, taken from a radar generated ballistics table a test
projectile fired at an initial velocity of 2,723 ft/s drops to 2,332
at 300 m, 1981 at 600, 1663 at 900, and 1384 at 1200. The decrease in
velocity and therefore the decrease in drag is 391 ft/s at 300 M, 351
from 300 to 600, 318 from 600 - 900 and 279 from 900 - 1200.

Yep. It's far from simple. If it were, lots more people would be good shots.

:-) Being a good shot has very little or nothing to do with
ballistics :-) More with having a good sight picture, steady hold and
good trigger squeeze :-)

Depends how far away you are, no?

Yes, to a certain extent. In the 1,000 yard rifle shooting where a
heavy bullet fired at a high velocity is required ballistics enter
into the equation only to the extent that the average shooter knows
what calibers work best. Or more frankly what doesn't work - the
7.62x51 NATO (.308 Winchester) doesn't work and one of the .300 or
larger magnums works better.

But with all the ballistics in the world, still, the major
requirements are still a firm stance, good sight picture and a good
trigger squeeze.

Ballistics would enter into it in the in the sense of selection of the
correct ammunition for the course of fire. That the ammunition is
constant in muzzle velocity, and accurate in the weapon used - even in
.22 ammunition some makes/lots shoot better than others. The big
military teams, for example, buy large quantities of ammunition and
then test each lot in an enclosed test range.

I once did a little "big bore", i.e., .30 caliber, military match
shooting, 100,200 and 300 yard, and nobody even talked about
ballistics. Other then the basic sight setting was "this" and 200 yds
was 7 clicks up, etc.


cheers,

John B.

Dumbass - you take one shot and correct from there.

On Monday, December 17, 2018 at 3:41:10 PM UTC-8, Mark J. wrote:
That extra 8 ounces blew my mind also.

When I was maybe 30, I was helping my dad, a long-time pistol round
reloader, mostly out of [my] curiosity. There was another seasoned
reloader there also. I measured one shell's worth of powder and was
surprised how excited they both got, exhorting me to avoid compressing
or tamping down the powder ?while scooping? (details and wording are
foggy years later). I was warned that any hint of ?compression? in the
powder could result in a overload that could destroy a pistol.

Who'd think you'd need to be careful working with explosives?

Mark J.

I would custom reload my .357 Magnum cartridges. We didn't use more, we used a hotter powder. The casing manufacturer would tell you maximum loads for the types of powder.

On Mon, 17 Dec 2018 12:44:42 -0500, Frank Krygowski
wrote:

On 12/17/2018 1:20 AM, John B. Slocomb wrote:
On Sun, 16 Dec 2018 22:59:23 -0500, Frank Krygowski
wrote:

On 12/16/2018 9:57 PM, John B. Slocomb wrote:
On Sun, 16 Dec 2018 21:15:00 -0500, Frank Krygowski
wrote:

On 12/16/2018 7:28 PM, John B. Slocomb wrote:


You are ignoring the effect of air resistance which means that the
speed of the projectile decreases with time during it's flight. And,
as the decrease in velocity results in an effective decrease in air
resistance the velocity decrease is not linier from muzzle to target.
For example, taken from a radar generated ballistics table a test
projectile fired at an initial velocity of 2,723 ft/s drops to 2,332
at 300 m, 1981 at 600, 1663 at 900, and 1384 at 1200. The decrease in
velocity and therefore the decrease in drag is 391 ft/s at 300 M, 351
from 300 to 600, 318 from 600 - 900 and 279 from 900 - 1200.

Yep. It's far from simple. If it were, lots more people would be good shots.

:-) Being a good shot has very little or nothing to do with
ballistics :-) More with having a good sight picture, steady hold and
good trigger squeeze :-)

Depends how far away you are, no?

Yes, to a certain extent. In the 1,000 yard rifle shooting where a
heavy bullet fired at a high velocity is required ballistics enter
into the equation only to the extent that the average shooter knows
what calibers work best. Or more frankly what doesn't work - the
7.62x51 NATO (.308 Winchester) doesn't work and one of the .300 or
larger magnums works better.

But with all the ballistics in the world, still, the major
requirements are still a firm stance, good sight picture and a good
trigger squeeze.

Ballistics would enter into it in the in the sense of selection of the
correct ammunition for the course of fire. That the ammunition is
constant in muzzle velocity, and accurate in the weapon used - even in
.22 ammunition some makes/lots shoot better than others. The big
military teams, for example, buy large quantities of ammunition and
then test each lot in an enclosed test range.

I once did a little "big bore", i.e., .30 caliber, military match
shooting, 100,200 and 300 yard, and nobody even talked about
ballistics. Other then the basic sight setting was "this" and 200 yds
was 7 clicks up, etc.

Here's some of what I had in mind:

https://www.longrangehunting.com/thr...results.80403/

https://www.huntinggearguy.com/tips/...range-hunting/

I suppose I shouldn't have said "lots more people." It really applies to
people shooting at relatively long but variable ranges.

My experience - hunting is that most people sight in a weapon at a
specific range or perhaps two ranges and then guesstimate the rest,
partially because most people can't really estimate distance well :-)

Depending on a ballistics chart, as one writer mentioned, doesn't work
well. If for no other reason then air density varies from day to day,
and of course with variations in altitude, which of course effects a
supersonic bullet. Even aircraft, relatively slow vehicles, use both
atmospheric pressure and density in calculating their take off roll.

Target shooters, of course, don't guesstimate anything. They will have
tested the weapon at all ranges and have written down the proper sight
settings.

An example - most pistol "bulls eye" target shooters shoot very
lightly loaded ammunition. Some even use two types, 50 yard and 25
yard. If one is a hand loader, making your own ammo, then one develops
loads based on two things, recoil and accuracy. I've done this myself,
1/10 grain more powder? 1/10 less powder? Now, certainly changing the
powder load effects velocity and of course ballistics, but no one ever
mentions it or uses it in calculations.

cheers,

John B.

On Mon, 17 Dec 2018 11:02:41 -0800, Jeff Liebermann
wrote:

On Mon, 17 Dec 2018 07:28:37 +0700, John B. Slocomb
wrote:

Acceleration of gravity = g = 32 ft/sec/sec
Let's say the trajectory height is 100 ft and the range is 1000 ft.
sqrt(height/0.5(g)) = time_of_flight
sqrt(100/0.5(32)) = (10/4) = 2.5 sec
At 1000ft, the muzzle velocity would be 1000/2.5 = 400ft/sec

Or something like that.

You are ignoring the effect of air resistance which means that the
speed of the projectile decreases with time during it's flight. And,
as the decrease in velocity results in an effective decrease in air
resistance the velocity decrease is not linier from muzzle to target.
For example, taken from a radar generated ballistics table a test
projectile fired at an initial velocity of 2,723 ft/s drops to 2,332
at 300 m, 1981 at 600, 1663 at 900, and 1384 at 1200. The decrease in
velocity and therefore the decrease in drag is 391 ft/s at 300 M, 351
from 300 to 600, 318 from 600 - 900 and 279 from 900 - 1200.
:-)

Ok, I yield. Air resistance is significant and can't be ignored.

"Projectile Motion with Air Resistance"
http://farside.ph.utexas.edu/teaching/336k/Newtonhtml/node29.html
We thus conclude that if air resistance is significant
then it causes the horizontal range of the projectile to
scale linearly, rather than quadratically, with the launch
velocity.

Methinks I could use this to produce a tolerable balistic
approximation, which could be used to calculate the muzzle velocity
given the impact velocity at a known distance. However, my math
sucks, I'm still doing battle with two kidney stones, and need to do
some repairs after last nights rain. Thanks for the corrections.

I'm not a ballistition (is that a word?) but from what little I've
read none of the multitude of formulas actually provides accurate
results in all cases. See
https://en.wikipedia.org/wiki/External_ballistics
for probably more then you want to know :-)

cheers,

John B.

On Mon, 17 Dec 2018 15:41:14 -0800, "Mark J."
wrote:

On 12/15/2018 9:58 PM, John B. Slocomb wrote:
On Sat, 15 Dec 2018 21:39:19 -0800 (PST), Sir Ridesalot
wrote:

On Saturday, December 15, 2018 at 10:43:29 PM UTC-5, John B. Slocomb wrote:
On Sat, 15 Dec 2018 16:20:42 -0800 (PST), jbeattie
wrote:

On Saturday, December 15, 2018 at 1:59:24 PM UTC-8, AMuzi wrote:
On 12/15/2018 3:04 PM, Emanuel Berg wrote:
Frank Krygowski wrote:

Emanuel, with all due respect, you should
spend the winter reading a physics book or
two. Or three. Skip the parts on electricity,
atomic physics, etc. Concentrate on forces,
motion, work, energy etc. - the parts that
apply to bicycles. [...]

Blah blah blah, you have told me this at least
a dozen times by now. Probably because it is
easier to be didactic/demeaning than to
actually answer the questions.


more.

I left school without having slept through even one physics
class. My reference work here is a 1955 high school textbook
for $1 (9 Kr). I don't know all of even that, but I
understand the world well enough to know that this headline
last week:

https://www.dailymail.co.uk/sciencet...soon-2022.html

was completely ridiculous. The chamber pressures are in the
same range, but not power, not even within a magnitude*!
Power is work over time. Without some grasp of the actual
world, you would not have laughed aloud when reading the
headline, etc.

*A typical 120mm tank round is 7.5 kilos of depleted uranium
moving at 1700 m/s. The new 6.8 rifle typically moves 7.5
grams at 850 m/s. That's why you need basic physics.

BTW, here's an interesting case that crossed my desk: https://www.bendbulletin.com/localst...killed-in-tank https://www.oregonlive.com/pacific-n...explosion.html Interesting object lesson for re-loaders. I'm representing a party on a collateral insurance issue. I've represented a couple big gun makers in over-pressure cases. Reloads. Too much powder or the wrong powder can blow-up guns large and small.

-- Jay Beattie.

One of the things I notices in the reference was that the gun had been
"de-militarized" and that "was restored by Preston to working order".
The term "de-militarized", at least as used by the U.S.A.F., means
that the weapon is modified to a point that it cannot be fired, and
cannot be repaired. In small arms usually by cutting the receiver and
barrel into at least two parts, usually with a cutting torch.

cheers,

John B.

I read the Preston put in 8oz. more powder than was the recommended load and was told that if he fired that cartridge it'd blow up the gun. Preston was also persuaded to take out more insurance due to that overloaded cartridge.


Yes, I read that part too. I used to hand load for varmint rifles and
of course we were always trying for that little extra speed, but we
were also careful to inspect cartridge cases for signs of over
pressure. I simply can't imagine anyone just shoveling in 8 ounces of
extra powder. Particularly after someone "in the business" told not
to.

That extra 8 ounces blew my mind also.

When I was maybe 30, I was helping my dad, a long-time pistol round
reloader, mostly out of [my] curiosity. There was another seasoned
reloader there also. I measured one shell's worth of powder and was
surprised how excited they both got, exhorting me to avoid compressing
or tamping down the powder ?while scooping? (details and wording are
foggy years later). I was warned that any hint of ?compression? in the
powder could result in a overload that could destroy a pistol.

Who'd think you'd need to be careful working with explosives?

Mark J.

True. Gun powders are manufactured as grains and any packing or
tamping down would allow more grains in the same space (measure). More
explosive in the same place equals higher pressures. People that are
loading right up to the maximum will weigh the powder rather then use
a mechanical measure.

cheers,

John B.