settling in

[peerlesscowboy]

Is it possible that a bullet will exibit rather lackluster accuracy at close range and then "settle in" and be exceptionally accurate at long range? For example; 2" - 3" groups on paper at 100 yards but consistently hit a 5 gallon bucket at 1000 yards [smilie=w:

[doubs43]

Doesn't seem likely...... but, then, whatta I know? :rolleyes:

[Doc Highwall]

Yes. The truth is because it was close you did not concentrate, and then when it was farther away you knew you had to concentrate and did what you were suppose to do. When it was close your mind set was this will be easy. Ask me how I know.

[John Taylor]

I have only seen this on high velocity boatails. There was a book telling about it that was printed around 1950. Another gunsmith told me about it 30 years ago and I made him prove it at the range. Was shooting a 300 Win. Mag with a 31" bull barrel and a 16 power scope.

[firefly1957]

Elmer Keith wrote on a 45 Sharps doing that with a heavy bullet He thought it took a while for the bullet to get stabil. Also if you want to torture yourself you might read Dr. Mann's "The flight of the bullet" he discovered that a tight group at one distance did not mean that all the bullets followed the same path to the group.

[leadman]

My 300 Whisper shoots 240gr Sierra's into the same group size at 100 yards and 200 yards. Sometimes it is even a little smaller at 200 yards.

[gewehrfreund]

Have never heard this happening with cast, but it seems possible. The phenomenon of "going to sleep" after a certain distance seems to be more prevalent with jacketed boattails, however.

[Potsy]

I read where Dave Miller tests his rifles at 200 or 300 yards (don't remember which, been a long time since I read it). The theory being that the bullet would "settle down" and groups at that range would often not be bigger than those at 100.
If I'm remembering right, he was refering to a .300 Weatherby and a 180 Nosler Ballistic Tip.

I've also often wondered when reading some of the gun scibes who suggest that a 1.5" group is acceptable for deer hunting a 400 yards may not be experiencing some of the same phenomenon. A 1.5" group @ 100 yards is not necessarily 6" @ 400 yards.

Aside from bullets being bigger and velocities being lower, I don't know why it wouldn't apply to cast at long range but I can't speak with any experience on the matter. I haven't taken my .45-70 #1 past 100 yards and thats the only gun I cast for capable of it.

[felix]

It has to do with the pressure at the muzzle when the tail of the projectile exits. All the litigating factors apply. ... felix

[41wyom]

The condition does exist. Has something to do the projectile's flight path and variability in the amount of precessing activity around its axis as it is moving downrange.

One of our club members demonstrated this on our silhouette range. He set-up large sheets of paper in frames at 50, 100, 150 and 200-meters. An aiming point was on the first sheet In most cases the groups on the further sheets were larger than the sheet preceeding it. But one load behaved inversely with the smallest group at 200-meters. It was a jacketed bullet.

[Potsy]

Is "yaw" the term we're looking for here? And it's effect on long range vs. short range accuracy?

[felix]

Yeah, Potsy! ... felix

[Tatume]

I've heard people make this claim for years. Think about this: if the bullet is away from the line of sight at 100 yards, how does it know how to find its way back at 200 yards?

A gun writer, I think I was John Barnsness, offered a hypothesis that sounds reasonable. He postulated that the zero-parallax setting of the scope is probably set at about 200 yards, and the shooter is not consistently holding his eye in the center of the scope. This is a lot more plausible than the "smart bullet" hypothesis.

[felix]

The yaw is circular about a center line. ... felix

[onesonek]

I've heard people make this claim for years. Think about this: if the bullet is away from the line of sight at 100 yards, how does it know how to find its way back at 200 yards?

A gun writer, I think I was John Barnsness, offered a hypothesis that sounds reasonable. He postulated that the zero-parallax setting of the scope is probably set at about 200 yards, and the shooter is not consistently holding his eye in the center of the scope. This is a lot more plausible than the "smart bullet" hypothesis.

There are mechanical components, like the parallax, and or other related to the gun itself like twist rates. Then there are the fundamental mechanics in shooting, as Doc Highwall mentioned. And then the physical mechanics of internal and external ballistics that Felix touched on.

Line of sight and or trajectory, has little to do with accuracy, or the question of the OP. Groups size denotes accuracy. But it is possible and not uncommon with good shooting fundamentals, along with adjustable parallex scope, or with any sighting system, not to have the best group size at a 100 yds. (or shorter), and find it tighten up somewhere down range. It's not that they are "smart bullets", it's just how all the components come together. Most of it deals with speed, pressure, and stability/twist factors, along with bullet/boolit design. That's why you see many twist rates available. But production guns, are set with a general twist, that kind of fill most needs. Each barrel will have it's particular likes or wants, beyond that.

Fixed parallex scopes, accommodate most common general ranges, and Barsness is right, (" the shooter is not consistently holding his eye in the center of the scope"), but that is related to shooting fundamentals, not accuracy potential or issues. Adjustable Parallex correct for parallex free at a given ranges, but still do not correct poor fundamental shooting skills, nor do they correct or change the other issues.

[Heavy lead]

I have a .223 flatop AR and a 22-250 that shoots as well or better at 200 than at 100 yards.

[firefly1957]

Tatume DR Mann had no scope he also used lead bullets that were swaged. Like said above the bullet can travel in spiral path and MAY intersect at several points along course. These are normally small spirals some guns being worse then others.

Dr. Mann had a set up were barrel was always in the same position in a jig when fired bullets passed though thin paper for 100 yds. and papers were compared for bullet path.

[felix]

I have a .223 flatop AR and a 22-250 that shoots as well or better at 200 than at 100 yards.

Try a shorter bullet with a faster powder for your closer ranges. If wild, go back to a slower powder, but with slightly less of amount than for your longer bullet. ... felix

[Doc Highwall]

Actually Dr Mann use a scope a 16X Sidle but is was used more for aligning the targets at each distance and he mentions that using it with his Rock of Gibraltar.
In his book on page 46 it shows a scope mounted on a barrel, but this means nothing as his barrels were mounted much like today's universal receivers and only were used to make sure that the barrel was aiming at the same place before firing to eliminate human error.
Dr Mann was ahead of his time, think of how he would do today with our modern equipment. Now imagine being able to work with him.

[uscra112]

There is the phenomenon of the boolit precessing (wobbling) like a gyroscope for the first part of it's flight, then "going to sleep". This has been studied to death, and was written about in the Rifleman back when it was more than an advertising carrier. While it's precessing, the asymmetrical draq forces make the projectile fly in a spiral. Thing is, all the sources I've read say that the deviation due to this cause is much smaller than your close-range groups. On the order of 1/4" for a .30-06 M1 bullet, if I remember aright. Would be worse if your boolit bases and/or crown aren't perfect, but I can't see it being 2 inches worse.

[firefly1957]

Doc Highwall It has been a while since I read Dr. Mann's book I considered rereading it after a post in another thread then remembered just how tedious his experiments were. I do not think I could work with him I suspect he was an obsessive-compulsive personality. I base that on the family members foreword in my NRA reprint of his book along with his determination. I think Fishing will take priority over going though it again for this summer!

I Have a Shilo-Sharps that will shoot a three inch group with a 700 gr PP bullet at 100 yds off hand and all bullets show yaw on paper. I have often wondered if it would close up at 200 or more yards or get worse groups but have never pursued it. My rifling is 1-36 and those bullets were loaded over 150 grs FG card board wad .2" grease cookie. Any gun that will shoot a 3" 100 yd. group offhand has something good going and with bullets tipped yet? I reduced Lyman mold to 540 grs. (mold is adjustable) and also use mostly a 450 gr 50-70 bullet which will shoot 2 inch 100 yd. groups (this is my hunting load it is a bit much for whitetail deer)

I suppose the best way a person could describe a bullet in flight is to watch a dart thrown by hand it takes a while before it becomes stable in flight same for arrows but harder to see at the speeds they are going now. I have a Squib Load for 44 special that uses 1 grain of Bullseye powder a large pistol primer and a 232 gr semiwadcutter bullet pushed all the way in the case as far as it will go. These loads are slow and you can see the bullet in flight the base of the bullet wobbles in flight. These loads also are dangerous and have killed a rabbit and possum and will go though a 1/2 inch of pine! I have fired that load in both 3 inch Charter Arms Bulldog and 8 3/8 model 29 .

[onesonek]

Thing is, all the sources I've read say that the deviation due to this cause is much smaller than your close-range groups. On the order of 1/4" for a .30-06 M1 bullet, if I remember aright. Would be worse if your boolit bases and/or crown aren't perfect, but I can't see it being 2 inches worse.

This is what I have found also, and haven't seen it worse than a 1/2", at least in jacketed. I can't say for cast, as I haven't had the time in with them yet. But beyond that, then I would suspect it is the shooter.

[Echo]

All the litigating factors apply. ... felix

Keyboard error, Felix - your finger hit the 'l' instead of the 'm'. We don't need no stinkin' litigators!

[felix]

Yep, Echo, my error. ... felix

[MtGun44]

I have had some loads that shoot exactly the same or even slightly better at 200 as at
100. My theory is that the bullet is still gyrating from launch forces and that they eventually
dampen out and the bullet flies more consistently in the downrange portion of the trajectory.

Seems reasonable, but I have no proof other than the targets.

There is some proof that the bullet is more stable downrange in Hatcher's Notebook. In
designing the standard Army rifle range, there were some large oak timbers specified and
testing was done to verify that the std .30-06 ammo in the Army rifles would not penetrate
these timbers. Once a few ranges were built, reports of bullets penetrating these timbers
were recieved. Testing again, the timbers could not be penetrated -- WHEN TESTED AT
SHORT RANGE. When hit by a bullet at long range, the bullet was more stable and was
able to penetrate much farther. The close range test shots had bullets yawing in the
wood and stopping more quickly. Pretty much proof that the bullet is significantly more stable at
long range after initial forces have dampened out.

Bill

[John Taylor]

When I first wanted to shoot long range I had an old 30-06 Remington. It shot 3" at 100 yards. The old gunsmith I was working for said not to pay any attention to the 100 yard group and try it at longer range. At 200 it was 2&3/4", at 300 it was 2&3/4" at 400 it was all over the place. This was with 180 game king. That's when I decided to go with a new barrel. Sighted in at 200 and never shot it once at 100. At 600 I could hit a quart oil can every shot after zero in. The barrel was 31" long and heavy, chambered in 300 mag. Velocity was just under 3400 fps. Took 40 clicks on the scope for 600 yards.