On 12/19/2018 5:52 PM, John B. Slocomb wrote:
On Wed, 19 Dec 2018 09:20:10 -0800 (PST), wrote:

On Monday, December 17, 2018 at 6:16:15 PM UTC-8, John B. Slocomb wrote:
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.

John - it wasn't until around WW I that bullets became supersonic.

The is utter bull****.

Between 1867 and 1900 there were at least 33 cartridges developed and
marketed that were supersonic (speed of sound = 1125 ft/sec).

There is an old saying, "Better to be silent and be thought a fool
then to open one's mouth and prove it" that apparently you never
heard. Or if you did you ignored it.

example:
http://gundata.org/cartridge/103/.45-70-government/


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