Precision vs Accuracy revisited

[northmn]

Frizzen asked a question concerning accuracy and breech plug configuration, an answer to which I have no clue, however as common other questions evolved.  Larry Pletcher ahs done several experiments with issues concerning accuracy.  Phil's question concerns precision.  Precision would lie in the barrel, for instance.  A Getz barrel has the same precision whether mounted on a rifle using a small Siler lock or a Brown Bess lock, just as a smooth bore barrel would havve the same precision whether made into a trade gun or in an in line.  Given the best combinations of patch and ball that barrel has to the potential to shoot a group of a given size.
Many spend a lot of money buying the perceived best barrels.  I put to you that design of the rifle or pistol may dictate whether that money is well spent.  Accuracy is a complex issue of design and components.  There is an arguement that if you have a barrel that shoots two inch groups and you can hold into a 4 inch group that your total group will be 6 inches.  Possibly, but I shot Numrich barrels for some time.  While not grossly inaccurate, they performed well for me.  They were inexpensive compared to the better barrels but were shallower gooved and seemed to need to be "shot in" more. I knew a couple of competitors that were very tough to beat shooting the old CVA Mountain Rifle (one of CVA's best that they canned to make the modern wonders). 
When Larry does his experiments on lock speed we are dealing with a percieved accuracy issue, namely the concept that the gun barrel will move less after the trigger is pulled with a faster lock. Yet flintlock shooters often beat percussion shooters because they learn to follow through.  Just some thoughts for discusssion.

DP 

[Mike R]

precision and accuracy are sometimes confused terms--when applied to the group of holes on target they mean different things: a precise group is a tight group; an accurate group is one centered on the bullseye.  Groups can be precise and inaccurate [tight groups off center] and imprecise groups can be accurate [centered on the bull].  The target shooter/hunter usually wants both precision and accuracy. Precision has to do with tolerances/quality of barrels, consistency of loads, shooter's skill, etc.; and accuracy has to do with sight alignment, lock speeds, shooter's skill, winds, etc...shooter skill figures in both terms, but other factors differ. 

[timM]

Many spend a lot of money buying the perceived best barrels.  I put to you that design of the rifle or pistol may dictate whether that money is well spent

I agree with this statement.  There are several factors beyond the barrel that contribute to having an accurate rifle.

Conversely, an exceptionally accurate piece will boil down to the precision of the barrel when all other variables are manicured and equal. A good barrel is the heart of an accurate piece......everytime.

[Standing Bear]

A precision barrel, precisely loaded and sights correctly regulated makes for an an accurate rifle.  Optimum operation of an accurate rifle is optional.

A certain minimum level of equipment is required for good operation to come to the front.

Practice does NOT make perfect . . . PERFECT practice makes perfect.

TC

[Mike R]

"Accuracy pertains to the average error and precision to grouping."  --SCL


Yeah, That is what I said above in more common terms. It is a statistical thing.  Another way to analogize it is to consider the pattern of a shotgun vs a rifle:  the wide shot pattern centered on a bullseye is just as accurate as a tight rifle group on a bullseye--but less precise.  When alot of folks think/talk about "accuracy" they are really thinking about precision and assume the group is on target. 

[northmn]

Actually I think they hold that with the 4" ability and 2 inch group that an occaisional shot will stray out 3 inches from center.  I think the sum of squares may be more a "typical" group.  Sometimes the shooter gets lucky and the one inch variation of the gun causes a one inch stray and may do so enough for the shooter to do better than normal.  One of the things about this issue is the fact that it is rare that sights are perfectly "in" also.  Even with a scope on a varmit rifle I have seen times when the goup wants to hang on one side of center and when you give it a click it is now on the other side of center.  To shoot a 1" target consistantly the precision may have to be 3/4 inch or whatever.
To make an accurate rilfe, one needs a barrel capable of a high degree of precision, good sights, good triggers and an excellent lock.  At what point are we throwing away money on the  precision issue

DP 

[Ezra]

It really doesn't matter to me, as I am neither...


Ez

[Standing Bear]

?

Accuracy has everything to do with GROUPING ability.  "Only accurate rifles are interesting" - T. Whelend ?

A firearm of any description capable of consistently shooting a single projectile into one minute of angle is more accurate than one that consistently shoots into 4 minutes of angle.

Location of the group is regulation of the sights.

Precision is how well the shooter operates an otherwise accurate firearm.  Over many shots, a nimrod with poor technique will make an otherwise accurate rifle look bad but even the most accomplished shooter cannot improve an inaccurate one.

TC

[timM]

 A rifle that is capable of accuracy beyond the shooters ability is a confidence builder and a tool to improve with. 
 
TC.....Townsend Whelan's  quote came to mind earlier when I first read this thread. 
tim

[Standing Bear]

Great point, Tim.  And again an accurate rifle that is also pretty is a true joy.
TC

[northmn]

Unfortunately you have it backwards as most shooters do.  Precision is the ability to group and accuracy is the ability to hit.  The concept is correct.  Its similar to a machinists measuring tool where it can be very precise but not necessarily accurate in its measurements.  Its graduations may be consistant but it may be off by .0001 for instance.  Machinists use that termonology in that manner. We have test weights in the lab to guarantee that the scales actually weigh a gram, even though they are graduated at .01 grams.  this is again standard industrail termonology.  A good example of what effects accuracy is the use of the fixed sights.  Today most modern rifles do not even have sights as scopes are attached after purchase because most can shoot a scope more accurately with better placement at longer ranges.
Almost any rifle barrel will outshoot the shooter using iron sights.  Add the lock and trigger system and you have the accuracy issue.  Also even a small thing like fit of the rifle will deter the ability to hit a target if the fit is very poor.  Remington actions are popular with snipers because they have a fast lock time.  Later percussion locks are designed with a stirrup to speed up lock time.  Underhammers are often used on bench guns and in-line were introduced way back when. These are all add on's to try to take advantage of the precision of the equipment.  In totality you have what is the accurate rifle.  After a point weight does not increase the precision of a barrel, I would guess that a 40 chunk gun in 15/16 configuration may have the same grouping ability as one in 1 1/8, but the weight permits a steadier hold.   Lapping a 13/16 barrel to bench standards may be a waste for an offhand rifle.

DP   

[timM]

If you have the skill to properly bench a rifle, it is no sweat to wring out a rifle and it's load potential with iron sights.  So there's the first place a shooter should be able to out shoot the rifles capability.   

Being effective with iron sights is a confidence game.  Example; long range Military or NRA matches.  Looking at the target at 600 yards over iron sights, you will find the bullseye hiding behind the front post, yet see how effectively the serious competitors engage these targets.  Technique and confidence with an otherwise accurate rifle can net amazing results with iron sights.

I personally have found success with almost typical looking sights that give me a Bomar sight picture. I have no alibi with this sight at longer ranges.  A pin head and notch have also worked really well for me. 

[northmn]

Longrange and NRA matches are shot with peep sights not nonadjustable open iron sights witha V for a rear sight.  Consider a repo build of a rifle using a Queen Ann flintlock lock and a single trigger.  You likely will not be able to shoot that as well as the barrel shoots.

DP

[Standing Bear]

I agree, Tim.  The iron sights you mention in NRA and military sights are indeed peep and adjustable. 

I worked with and often visited with Bob Korzinewsky (as he said it rhymes with corn whiskey), his wife and son Norbert often in N Longview, TX (BOMAR).  Even got them to make and catalog a BMR sight with a full 3/8" dovetail instead of over pins, very narrow slot in the sight blade to be opened as needed for owner's sight radius and preferred sight width.  The ensuing catalog number has -ML on the end.  I have several mounted on different MLs and a Jim Clark Ruger .22 (not a -ML).  Still have one that has never been mounted.

Back to the discussion at hand.  An accurate tool gun or otherwise is still accurate.  If the base line, reference or sight regulation misses the target, the tool is no less accurate.

[hanshi]

As before I remain just a tad confused.  An inaccurate but precise rifle becomes suddenly accurate with just a turn of a scope knob or the moving of an iron sight?  I can accept there is a difference between "precise" and "accurate".  It would seem to me that it would only be of interest to engineers and machinists.  Most folks use the words almost interchangeably as do I.  It's simple and works for the masses.  Perhaps, then, we should go back to David Crockett (or at least Fess Parker) and use the term "true".  It combines all the elements of both "precise" and "accurate" and also implies that the gun performs well for the shooter.  I don't care whether my gun is "precise" or "accurate"; I just want it to make small groups at the aiming point.  

[timM]

 The level of mechanical precision is dictated by the accuracy requirement.  Regardless, the accuracy quest should be to minimize mechanical errors and free up the shooter to contend with the variables related to shooting conditions.  

I will propose that it is easier to shoot higher scores with a rifle that is more accurate than the job demands. tim

[northmn]

As before I remain just a tad confused.  An inaccurate but precise rifle becomes suddenly accurate with just a turn of a scope knob or the moving of an iron sight?  I can accept there is a difference between "precise" and "accurate".  It would seem to me that it would only be of interest to engineers and machinists.  Most folks use the words almost interchangeably as do I.  It's simple and works for the masses.  Perhaps, then, we should go back to David Crockett (or at least Fess Parker) and use the term "true".  It combines all the elements of both "precise" and "accurate" and also implies that the gun performs well for the shooter.  I don't care whether my gun is "precise" or "accurate"; I just want it to make small groups at the aiming point. 

Mostly you have it correct.  Also most use accuracy for reference to a rifle interchangeably with percision and getting too hung up on the technical differences may not add a lot to shooting.  Making small groups at the aiming point is almost an obsession with some.  However, some shooting is a give and take game.  You would not be able to shoot small groups offhand with a heavy bench rifle, but it is capable of pretty fair accuracy.  What I sometimes question is whether we look at the gun as a total shooting system.  Many think its all in the barrel and you will shoot better if you just pay more for the barrel.

DP

[Daryl]

  You would not be able to shoot small groups offhand with a heavy bench rifle, but it is capable of pretty fair accuracy.  What I sometimes question is whether we look at the gun as a total shooting system.  Many think its all in the barrel and you will shoot better if you just pay more for the barrel.
DP

I beg to differ on that point. My best offhand score was with an unlimited BR .308, weight 22 pounds.  I shot an 98 at 100 yards with that rifle, some 6 to 7 points better than I was shooting with my own match rifle, .308, of course. Too - I was only 24 at the time. and in good shape.   Harry Pope's idea of the perfect offhand rifle for a man was 16 pounds, and 12 pounds for a women. Of course he was talking of hooked butt plates and plam rests.

[Mike R]

In order to reduce the variables of hitting your target it is best to start out with a precise rifle/load.  Accuracy [hitting the target] is a function of several things, but if you start out with imprecision built in to the tool, accuracy will suffer. That is why I [most shooters] stress the difference between the two terms. You should first seek out the best barrel/load combo that gives the tightest group.  Then you do what it takes to transfer the center of that tight group to the center of the target.  Offhand shooting as opposed to bench shooting introduces inaccuracies, but the precision factor is under control!  Imprecision adds to inaccuracies.  As to the heavy vs light rifle debate--when I fired on a college small bore team we used extra weights hung on our already heavy rifles to shoot offhand to 'steady' them. But as I age and as my offhand style has evolved I now prefer lighter rifles.  The style of shooting offhand determines in part which you prefer. The heavier rifle helps those that hold a steady aim and squeeze. I find that I can hit better now by a style closer to 'snap shooting'.  I read that some 18th cent riflemen did not hold an aim at all, but shot as the sights arrived on mark, when raising the piece.  Each to his own...

[northmn]

Heavy v light is relative.  When I used the example of a Bench gun I meant it as an example of too heavy to be used for offhand.  A typical ML bench gun (not a modern 308) is generally very muzzle heavy and would be a bear to shoot offhand for a typical shooter.  Some have a 1 1/4 inch straight barrel over 36 inches long.   Another example to make the point would be for someone that generally shoots about a 14 inch pull which fits them to try and shoot a 15 inch pull.  While you can adapt the awkwardness makes for problems that could lead to inaccuracies.   One example of a system is a 22 hornet TC Contender I had once.  Scoped off a bench I could shoot very tight groups with it, but I sold it because I could not carry a bench rest with me.  It had a 15" bull barrel and was awkward to shoot unless off of a rest.  It was not my bag of tea.  Imprecission leads to inaccuracies, but precision and accuracy need to be practically defined.   A squirrel rifle with iron sights does not really need minute of angle grouping at 100 yards, and with a ML you will not get it in typical calibers.  Testing a squirrel rifle at say 35 yards is more practical.  A ML deer rifle with open iron sights does not to be able to group one inch at 100 yards either.  An off hand target rifle will benefit from that precision, but it takes a very good shooter to take advantage of it. 

DP

[hanshi]

Like Mike R, I seem to do my best off hand shooting by (inappropriately called) "snap" shooting.  I think it is more of an "in the zone" thing which depends a lot on rifle fit and familiarity. 

A good barrel is always to be preferred to a bad barrel, of course.  The barrel should (preferably) be more precise than the shooter, though this is not always the case.  I agree there is more to the equation and that a rifle is indeed a "shooting system". 

I demand that my barrel out shoot me (easy to do) and that the whole system be able to take advantage of that barrel.  It must also fit me and feel right.  As a ROT I consider squirrel type accuracy (small bores primarily) for my purposes to be 1" or under at 25 to 30 yards, deer rifle (.45 & up)  to be close to that at 50 yards.  All from a bench, of course.  Better is wonderful and a bit less is okay.  I say okay because I value convenience and reasonably easy loading of a hunting rifle at least as much as I value precision/accuracy.  If my rifle only does 3" at 50 yards I don't sweat it as that is still in the deer game.   I don't like to have to go "out of my way" to get just a little better precision/accuracy.  I look at it as having a job to do and if the tool does the job well, that's all I ask.

[Pete G.]

Accuracy is the ability to hit ones target; nothing more, nothing less, but there is another factor in this that no one has yet mentioned and that is consistency. Go back to the 4 inch barrel and the two inch shooter. Granted this combination gives a theoretical 6" group, but occasionally, the shooter's deviation to the right is offset by the barrels deviation to the left and you can end up with a 2" target. This means that, all else being equal, such a combination could give 100 points in one match and 60 in the next, whereas a more consistent barrel would be more likely in the 90s for every match. My shooting is wild enough without that kind of deviation. I would rather spend the extra money on a good barrel any day, whether my ability can utilize it fully or not. It just makes things easier.

[Daryl]

Accuracy is the ability to hit ones target; nothing more, nothing less, but there is another factor in this that no one has yet mentioned and that is consistency. Go back to the 4 inch barrel and the two inch shooter. Granted this combination gives a theoretical 6" group, but occasionally, the shooter's deviation to the right is offset by the barrels deviation to the left and you can end up with a 2" target. This means that, all else being equal, such a combination could give 100 points in one match and 60 in the next, whereas a more consistent barrel would be more likely in the 90s for every match. My shooting is wild enough without that kind of deviation. I would rather spend the extra money on a good barrel any day, whether my ability can utilize it fully or not. It just makes things easier.

Good point Pete - which is why aggregates are always won by those who not only practise and find accurate loads for their rifles, but are able to shoot that accurate load consistantly over a time period.  The odd 'lucky' group that happens when the planets align just right - or wrong - wins the odd match or contest, but cannot compete with the precision of an accurate load shot by a precise shooter - or something like that.

[northmn]

Used to know a very good shot and a builder who used nothing but Douglas XX Premium barrels.  He sold a lot of rifles because the buyers seemed to feel if they bought one of his rifles they could shoot as well as he did.  He had one customer that was also a regular winner.  He also shot about 25 pounds of powder or so a year which I suspect had something to do with his wins.  His customer had done a lot of shooting also.  Upon occasion I would beat him using a rifle with a Numrich barrel which was not quite as precise as a Douglas, but the differences were very small and may have taken a Bench gun to take advantage of them.  Many fo the BPC long range shooters using Badger barrels are cussing out those using less expensive Green Mountain Barrels and the off the shelf Pedersoli Sharps as users of these ahve been stepping into the winners circle.  A long time ago I decided that I would rather pay $250 for a lock made to that standard than for a "match grade" barrel.  The lock would possibly permit me to shoot better.  Just haven't seen one.

DP

[Standing Bear]

Unless it is a flintlock, the barrel is #1, #2 and #3 on my list of importance.   If a flinter, then its barrel first and lock a close second.  A lock can be tuned.

Won many state and territorial championships with Douglas XX barrels.  Still have one in the raw and 4 in guns.  Wish they were still available.    The .40 flint has a XX and a Willie Cochran lock tuned by Tom Gillman.