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Group size is not "accuracy", but "precision" ?
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clarkm...@gmail.com
Feb 5, 2012, 12:37:44 PM2/5/12
to
http://en.wikipedia.org/wiki/Accuracy_and_precision
It looks like accuracy is how far from the bullseye that the bullets strike.
And precision is the size of the group.
I have been saying this wrong for so many years, I don't know if I can change.
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It looks like accuracy is how far from the bullseye that the bullets strike.
And precision is the size of the group.
I have been saying this wrong for so many years, I don't know if I can change.
-----------------------------------------------------------------
Learn about rec.guns at http://www.recguns.net
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nord...@yahoo.com
Feb 5, 2012, 5:35:16 PM2/5/12
to
# http://en.wikipedia.org/wiki/Accuracy_and_precision
#
# It looks like accuracy is how far from the bullseye that the bullets stri=
ke.
# And precision is the size of =A0the group.
#
# I have been saying this wrong for so many years, I don't know if I can ch=
ange.
At least you don't say "clip" when you mean "removable box magazine."
#
# It looks like accuracy is how far from the bullseye that the bullets stri=
ke.
# And precision is the size of =A0the group.
#
# I have been saying this wrong for so many years, I don't know if I can ch=
ange.
At least you don't say "clip" when you mean "removable box magazine."
TimR
Feb 5, 2012, 5:35:19 PM2/5/12
to
On Feb 5, 12:37=A0pm, "clarkmagnu...@gmail.com"
# It looks like accuracy is how far from the bullseye that the bullets stri=
ke.
# And precision is the size of =A0the group.
#
Yes, that is how we engineers have always used the terms.
The wiki article has a strange use of valid though. It says a
measurement that is both precise and accurate is valid. To me valid
relates to whether the measurement system measures the right quality.
For example, you could have a very sloppy scale, that measured only
plus or minus 25 pounds, but averaged the correct weight. It would be
accurate but not precise. You could have a very precise scale, that
measured plus or minus .01 pounds, but always read 10 pounds low;
that would be precise but not accurate. Neither would be valid if you
wanted to know height.
Within engineering, and guns for that matter, the other terms
frequently abused are tolerances and clearances. Tolerance means you
made the part very precisely. Clearance means the fit is loose. A
loose fit can be an accident if tolerances are sloppy, or it can be
deliberate if tolerances are held very tight.
# It looks like accuracy is how far from the bullseye that the bullets stri=
ke.
# And precision is the size of =A0the group.
#
Yes, that is how we engineers have always used the terms.
The wiki article has a strange use of valid though. It says a
measurement that is both precise and accurate is valid. To me valid
relates to whether the measurement system measures the right quality.
For example, you could have a very sloppy scale, that measured only
plus or minus 25 pounds, but averaged the correct weight. It would be
accurate but not precise. You could have a very precise scale, that
measured plus or minus .01 pounds, but always read 10 pounds low;
that would be precise but not accurate. Neither would be valid if you
wanted to know height.
Within engineering, and guns for that matter, the other terms
frequently abused are tolerances and clearances. Tolerance means you
made the part very precisely. Clearance means the fit is loose. A
loose fit can be an accident if tolerances are sloppy, or it can be
deliberate if tolerances are held very tight.
Argent
Feb 5, 2012, 5:35:22 PM2/5/12
to
On Feb 5, 10:37=A0am, "clarkmagnu...@gmail.com"
# It looks like accuracy is how far from the bullseye that the bullets stri=
ke.
# And precision is the size of =A0the group.
#
# I have been saying this wrong for so many years, I don't know if I can ch=
ange.
#
Something they harped on when I was a young engineer. They actually
used that as an example. I still mix them up.
# It looks like accuracy is how far from the bullseye that the bullets stri=
ke.
# And precision is the size of =A0the group.
#
# I have been saying this wrong for so many years, I don't know if I can ch=
ange.
#
Something they harped on when I was a young engineer. They actually
used that as an example. I still mix them up.
CS
Feb 5, 2012, 5:35:23 PM2/5/12
to
I think folks worry too much about both.
Unless one is in some sort of not-practical-shooting competition, worrying
about accuracy, precision, or whatever is a waste of time.
While I might be impressed with a shooter who can put a round in a bullseye
at 1,000 yards, or one who can send two or more rounds through the same hole
at 300 yards, my admiration is limited to the conditions where they can do
these great feats.
A bench rest at a target range is not real life, nor is the flat, level,
prone-friendly spot next to the bench.
Now, if a shooter can keep a 6" shot group at 100 yards while standing on
the steep side of a muddy creek in the pouring rain, that's somebody I'd
want watching my back.
CS
Unless one is in some sort of not-practical-shooting competition, worrying
about accuracy, precision, or whatever is a waste of time.
While I might be impressed with a shooter who can put a round in a bullseye
at 1,000 yards, or one who can send two or more rounds through the same hole
at 300 yards, my admiration is limited to the conditions where they can do
these great feats.
A bench rest at a target range is not real life, nor is the flat, level,
prone-friendly spot next to the bench.
Now, if a shooter can keep a 6" shot group at 100 yards while standing on
the steep side of a muddy creek in the pouring rain, that's somebody I'd
want watching my back.
CS
penultimate
Feb 5, 2012, 5:35:25 PM2/5/12
to
On Feb 5, 11:37=A0am, "clarkmagnu...@gmail.com"
# It looks like accuracy is how far from the bullseye that the bullets stri=
ke.
# And precision is the size of =A0the group.
#
# I have been saying this wrong for so many years, I don't know if I can ch=
ange.
Then again, Clark, you could edit the Wiki definition to impose your
alternate view of reality. Wiki is after all the product of millions
of monkeys given millions of typewriters. Generally the monkey that
gets there last prevails,.
# It looks like accuracy is how far from the bullseye that the bullets stri=
ke.
# And precision is the size of =A0the group.
#
# I have been saying this wrong for so many years, I don't know if I can ch=
ange.
Then again, Clark, you could edit the Wiki definition to impose your
alternate view of reality. Wiki is after all the product of millions
of monkeys given millions of typewriters. Generally the monkey that
gets there last prevails,.
Martin Eastburn
Feb 5, 2012, 10:24:11 PM2/5/12
to
This is why when qualifying for a team all you do is shoot
at the same spot over and over. If you make one hole (anywhere)
you have a job. If you are scattered everywhere you start
polishing boots.
e.g. gun in a vise that always shoots to the upper right -
just cal it down and to the left and you will have the same precision
and the accuracy merge to the same place.
Martin
at the same spot over and over. If you make one hole (anywhere)
you have a job. If you are scattered everywhere you start
polishing boots.
e.g. gun in a vise that always shoots to the upper right -
just cal it down and to the left and you will have the same precision
and the accuracy merge to the same place.
Martin
Murff
Feb 5, 2012, 10:24:12 PM2/5/12
to
On Sun, 05 Feb 2012 22:35:23 +0000, CS wrote:
#
# A bench rest at a target range is not real life, nor is the flat, level,
# prone-friendly spot next to the bench.
#
# Now, if a shooter can keep a 6" shot group at 100 yards while standing
# on the steep side of a muddy creek in the pouring rain, that's somebody
# I'd want watching my back.
Agreed entirely. At the (indoor, small-bore and airguns) range I
sometimes go to they're increasingly into benchrest competition. The
object of the exercise seems to be the elimination of variability.
Which I accept is a shooting discipline and their levels of precision are
something worthy of respect.
But it isn't for me. To overcome variability of range, wind, inclination
and to do so whilst not being seen by, and spooking, a wary quarry animal
is a far more interesting form of sport. In addition to the practical
aspect that venison and rabbit, duck, pheasant and goose all taste a good
deal better than does paper.
Murff...
#
# A bench rest at a target range is not real life, nor is the flat, level,
# prone-friendly spot next to the bench.
#
# Now, if a shooter can keep a 6" shot group at 100 yards while standing
# on the steep side of a muddy creek in the pouring rain, that's somebody
# I'd want watching my back.
Agreed entirely. At the (indoor, small-bore and airguns) range I
sometimes go to they're increasingly into benchrest competition. The
object of the exercise seems to be the elimination of variability.
Which I accept is a shooting discipline and their levels of precision are
something worthy of respect.
But it isn't for me. To overcome variability of range, wind, inclination
and to do so whilst not being seen by, and spooking, a wary quarry animal
is a far more interesting form of sport. In addition to the practical
aspect that venison and rabbit, duck, pheasant and goose all taste a good
deal better than does paper.
Murff...
SaPeIsMa
Feb 5, 2012, 11:40:39 PM2/5/12
to
<clarkm...@gmail.com> wrote in message
news:jgmep7$dbn$1...@news.albasani.net...
# http://en.wikipedia.org/wiki/Accuracy_and_precision
#
# It looks like accuracy is how far from the bullseye that the bullets
strike.
# And precision is the size of the group.
#
# I have been saying this wrong for so many years, I don't know if I can
change.
#
The way I learned was that an Accurate clock shows 12 o'clock when it's 12
o'clock
And a precise clock will tell you to the thousandth of a second what time it
is, right or wrong
To transfer that to a gun, is to say, (as you did) that an accurate gun will
hit where you aim it.
A precise gun will group tight where it hits, even though it's not where you
aim it.
Gunner Asch
Feb 6, 2012, 8:35:03 AM2/6/12
to
On Sun, 5 Feb 2012 22:35:23 +0000 (UTC), "CS" <dont...@sears.com>
wrote:
#I think folks worry too much about both.
#
#Unless one is in some sort of not-practical-shooting competition, worrying
#about accuracy, precision, or whatever is a waste of time.
#
#While I might be impressed with a shooter who can put a round in a bullseye
#at 1,000 yards, or one who can send two or more rounds through the same hole
#at 300 yards, my admiration is limited to the conditions where they can do
#these great feats.
#
#A bench rest at a target range is not real life, nor is the flat, level,
#prone-friendly spot next to the bench.
#
#Now, if a shooter can keep a 6" shot group at 100 yards while standing on
#the steep side of a muddy creek in the pouring rain, that's somebody I'd
#want watching my back.
#
#CS
Good point.
Gunner
wrote:
#I think folks worry too much about both.
#
#Unless one is in some sort of not-practical-shooting competition, worrying
#about accuracy, precision, or whatever is a waste of time.
#
#While I might be impressed with a shooter who can put a round in a bullseye
#at 1,000 yards, or one who can send two or more rounds through the same hole
#at 300 yards, my admiration is limited to the conditions where they can do
#these great feats.
#
#A bench rest at a target range is not real life, nor is the flat, level,
#prone-friendly spot next to the bench.
#
#Now, if a shooter can keep a 6" shot group at 100 yards while standing on
#the steep side of a muddy creek in the pouring rain, that's somebody I'd
#want watching my back.
#
#CS
Good point.
Gunner
Bob Holtzman
Feb 6, 2012, 2:23:44 PM2/6/12
to
On 2012-02-05, CS <dont...@sears.com> wrote:
# I think folks worry too much about both.
#
# Unless one is in some sort of not-practical-shooting competition, worrying
# about accuracy, precision, or whatever is a waste of time.
.......snip......
Unless, of course, you're trying to hit a prairie dog at 300 yds or an
enemy machine gunner at 800.
--
Bob Holtzman
# I think folks worry too much about both.
#
# Unless one is in some sort of not-practical-shooting competition, worrying
# about accuracy, precision, or whatever is a waste of time.
.......snip......
Unless, of course, you're trying to hit a prairie dog at 300 yds or an
enemy machine gunner at 800.
--
Bob Holtzman
TimR
Feb 6, 2012, 2:23:45 PM2/6/12
to
On Feb 5, 5:35=A0pm, "CS" <donts...@sears.com> wrote:
# I think folks worry too much about both.
#
# Unless one is in some sort of not-practical-shooting competition, worryin=
g
# about accuracy, precision, or whatever is a waste of time.
#
Depends.
I mostly hunt with low powered airguns. I have to hit a squirrel's
brain - not his head, his brain - first time at unknown ranges.
(short ranges, but given the looping trajectory, still important).
With firearms, no big deal. Anywhere in the chest is good enough.
# I think folks worry too much about both.
#
# Unless one is in some sort of not-practical-shooting competition, worryin=
g
# about accuracy, precision, or whatever is a waste of time.
#
Depends.
I mostly hunt with low powered airguns. I have to hit a squirrel's
brain - not his head, his brain - first time at unknown ranges.
(short ranges, but given the looping trajectory, still important).
With firearms, no big deal. Anywhere in the chest is good enough.
Bob Holtzman
Feb 6, 2012, 8:07:12 PM2/6/12
to
On 2012-02-06, TimR <timot...@aol.com> wrote:
# On Feb 5, 5:35=A0pm, "CS" <donts...@sears.com> wrote:
# # I think folks worry too much about both.
# # about accuracy, precision, or whatever is a waste of time.
# #
#
# Depends.
#
# I mostly hunt with low powered airguns. I have to hit a squirrel's
# brain - not his head, his brain - first time at unknown ranges.
# (short ranges, but given the looping trajectory, still important).
#
# With firearms, no big deal. Anywhere in the chest is good enough.
At 800-1000 yds in shifting winds? Right...no big deal...sure.
--
Bob Holtzman
# On Feb 5, 5:35=A0pm, "CS" <donts...@sears.com> wrote:
# # I think folks worry too much about both.
# #
# # Unless one is in some sort of not-practical-shooting competition, worryin=
# g
# # Unless one is in some sort of not-practical-shooting competition, worryin=
# # about accuracy, precision, or whatever is a waste of time.
# #
#
# Depends.
#
# I mostly hunt with low powered airguns. I have to hit a squirrel's
# brain - not his head, his brain - first time at unknown ranges.
# (short ranges, but given the looping trajectory, still important).
#
# With firearms, no big deal. Anywhere in the chest is good enough.
At 800-1000 yds in shifting winds? Right...no big deal...sure.
--
Bob Holtzman
Jim
Feb 6, 2012, 8:07:16 PM2/6/12
to
On Feb 6, 2:23=A0pm, TimR <timothy...@aol.com> wrote:
# I mostly hunt with low powered airguns. =A0I have to hit a squirrel's
# brain - not his head, his brain -
Brain shot. So to be that precise you need an accurate gun. (erizat
wrong) - Jim
# I mostly hunt with low powered airguns. =A0I have to hit a squirrel's
# brain - not his head, his brain -
Brain shot. So to be that precise you need an accurate gun. (erizat
wrong) - Jim
clarkm...@gmail.com
Feb 7, 2012, 8:54:07 AM2/7/12
to
I posted a fact about Che on his wiki page, was accused of vandalism, and got all my gun stuff on Wikipedia deleted.
Post something on rec.guns and it might get contradicted, but not deleted.
Post something on rec.guns and it might get contradicted, but not deleted.
snakehunter
Feb 7, 2012, 8:54:10 AM2/7/12
to
On Feb 6, 2:23=A0pm, Bob Holtzman <hol...@cox.net> wrote:
# On 2012-02-05, CS <donts...@sears.com> wrote:
# # I think folks worry too much about both.
# #
# # Unless one is in some sort of not-practical-shooting competition, worry=
ing
# # about accuracy, precision, or whatever is a waste of time.
#
# =A0 =A0 =A0 =A0 =A0 =A0 .......snip......
#
# Unless, of course, you're trying to hit a prairie dog at 300 yds or an
# enemy machine gunner at 800.
Exactly!
# On 2012-02-05, CS <donts...@sears.com> wrote:
# # I think folks worry too much about both.
# #
# # Unless one is in some sort of not-practical-shooting competition, worry=
ing
# # about accuracy, precision, or whatever is a waste of time.
#
# =A0 =A0 =A0 =A0 =A0 =A0 .......snip......
#
# Unless, of course, you're trying to hit a prairie dog at 300 yds or an
# enemy machine gunner at 800.
Exactly!
MNmineiro
Feb 9, 2012, 5:16:58 PM2/9/12
to
On Feb 7, 7:54=A0am, snakehunter <jumpingja...@comcast.net> wrote:
# On Feb 6, 2:23=3DA0pm, Bob Holtzman <hol...@cox.net> wrote:
# # On 2012-02-05, CS <donts...@sears.com> wrote:
# # # I think folks worry too much about both.
# # #
# # # Unless one is in some sort of not-practical-shooting competition, wor=
ry=3D
# ing
# # # about accuracy, precision, or whatever is a waste of time.
# #
# # =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 .......snip......
# #
#
# Exactly!
What an interesting string! Thanks Clark (Clarke?) for starting it.
I searched in vain, however, for mention of Kentucky windage and
Loosiana elevation!
# On Feb 6, 2:23=3DA0pm, Bob Holtzman <hol...@cox.net> wrote:
# # On 2012-02-05, CS <donts...@sears.com> wrote:
# # # I think folks worry too much about both.
# # #
# # # Unless one is in some sort of not-practical-shooting competition, wor=
ry=3D
# ing
# # # about accuracy, precision, or whatever is a waste of time.
# #
# # =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 .......snip......
# #
# # Unless, of course, you're trying to hit a prairie dog at 300 yds or an
# # enemy machine gunner at 800.
#
# Exactly!
What an interesting string! Thanks Clark (Clarke?) for starting it.
I searched in vain, however, for mention of Kentucky windage and
Loosiana elevation!
Bill Smith
Feb 11, 2012, 11:06:40 AM2/11/12
to
So what you're saying is; the accuracy (and precision) you're striving
for should match the goal you're trying to reach.
There aren't any disciplines of shooting that are easy to master. Some
are more physically demanding and some that are more technically
demanding, but none are easy. Go to a match, or any endeavor involving
firearms, of any sort, and you will see it's true. They all require
discipline, knowledge and experience to master.
Bill Smith
Dillon Pyron
Feb 15, 2012, 5:08:06 PM2/15/12
to
Thus spake TimR <timot...@aol.com> :
#On Feb 5, 12:37=A0pm, "clarkmagnu...@gmail.com"
#<clarkmagnu...@gmail.com> wrote:
## http://en.wikipedia.org/wiki/Accuracy_and_precision
##
## It looks like accuracy is how far from the bullseye that the bullets stri=
#ke.
## And precision is the size of =A0the group.
##
#
#Yes, that is how we engineers have always used the terms.
#
#The wiki article has a strange use of valid though. It says a
#measurement that is both precise and accurate is valid. To me valid
#relates to whether the measurement system measures the right quality.
#For example, you could have a very sloppy scale, that measured only
#plus or minus 25 pounds, but averaged the correct weight. It would be
#accurate but not precise. You could have a very precise scale, that
#measured plus or minus .01 pounds, but always read 10 pounds low;
#that would be precise but not accurate. Neither would be valid if you
#wanted to know height.
#
#Within engineering, and guns for that matter, the other terms
#frequently abused are tolerances and clearances. Tolerance means you
#made the part very precisely. Clearance means the fit is loose. A
#loose fit can be an accident if tolerances are sloppy, or it can be
#deliberate if tolerances are held very tight.
It also applies to allowables. The top ring on my racing motor is
.013 to .015, but the tolerance is +.0003 - .0002. In other words I
can be as big as .00133 but not closer than .0148. (in very, very hot
engines, the rings expand and you want to keep them a little "sloppy")
#On Feb 5, 12:37=A0pm, "clarkmagnu...@gmail.com"
#<clarkmagnu...@gmail.com> wrote:
## http://en.wikipedia.org/wiki/Accuracy_and_precision
##
## It looks like accuracy is how far from the bullseye that the bullets stri=
#ke.
## And precision is the size of =A0the group.
##
#
#Yes, that is how we engineers have always used the terms.
#
#The wiki article has a strange use of valid though. It says a
#measurement that is both precise and accurate is valid. To me valid
#relates to whether the measurement system measures the right quality.
#For example, you could have a very sloppy scale, that measured only
#plus or minus 25 pounds, but averaged the correct weight. It would be
#accurate but not precise. You could have a very precise scale, that
#measured plus or minus .01 pounds, but always read 10 pounds low;
#that would be precise but not accurate. Neither would be valid if you
#wanted to know height.
#
#Within engineering, and guns for that matter, the other terms
#frequently abused are tolerances and clearances. Tolerance means you
#made the part very precisely. Clearance means the fit is loose. A
#loose fit can be an accident if tolerances are sloppy, or it can be
#deliberate if tolerances are held very tight.
It also applies to allowables. The top ring on my racing motor is
.013 to .015, but the tolerance is +.0003 - .0002. In other words I
can be as big as .00133 but not closer than .0148. (in very, very hot
engines, the rings expand and you want to keep them a little "sloppy")
aez...@giganews.com
Feb 19, 2012, 8:13:37 PM2/19/12
to
#It also applies to allowables. The top ring on my racing motor is
#.013 to .015, but the tolerance is +.0003 - .0002. In other words I
#can be as big as .00133 but not closer than .0148. (in very, very hot
#engines, the rings expand and you want to keep them a little "sloppy")
All of this means nothing (precision) and (accuracy) means the same
thing putting the bullet in the target at whatever range you need to
shoot it at.
#.013 to .015, but the tolerance is +.0003 - .0002. In other words I
#can be as big as .00133 but not closer than .0148. (in very, very hot
#engines, the rings expand and you want to keep them a little "sloppy")
All of this means nothing (precision) and (accuracy) means the same
thing putting the bullet in the target at whatever range you need to
shoot it at.
Dillon Pyron
Mar 15, 2012, 9:00:30 PM3/15/12
to
Thus spake aez...@giganews.com :
##It also applies to allowables. The top ring on my racing motor is
##.013 to .015, but the tolerance is +.0003 - .0002. In other words I
##can be as big as .00133 but not closer than .0148. (in very, very hot
##engines, the rings expand and you want to keep them a little "sloppy")
#
#
# All of this means nothing (precision) and (accuracy) means the same
#thing putting the bullet in the target at whatever range you need to
#shoot it at.
Precision means you put four rounds close enough to make a four leaf
clover. Accurate means one of them made a hole in what you wanted to
shoot. What you want is precision AND accuracy.
##It also applies to allowables. The top ring on my racing motor is
##.013 to .015, but the tolerance is +.0003 - .0002. In other words I
##can be as big as .00133 but not closer than .0148. (in very, very hot
##engines, the rings expand and you want to keep them a little "sloppy")
#
#
# All of this means nothing (precision) and (accuracy) means the same
#thing putting the bullet in the target at whatever range you need to
#shoot it at.
Precision means you put four rounds close enough to make a four leaf
clover. Accurate means one of them made a hole in what you wanted to
shoot. What you want is precision AND accuracy.
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