Developing long range loads.

[Clover_Shooter]

When developing long-range loads, is your best 100-yard load also the best load at 400 or 600 yards and vice versa is your best long-range load also best at 100 yards. Do you develop a most accurate load for specifically for a given range? If so please list some loads that are for long range.
My 10-year-old son shot this group last year at 600 yards! (if picture comes out right)

[Lee C.]

Not always some boat tail bullets need some distance to get there optimal spin on the bullet. As i test different loads, i see they will open up about a 3rd more each 100yd of distance i shoot. I always shoot a 200yd 10 shoot group to make sure the load i come up with will hold up. A 200yd sight in around here is good. But if i was going out west for pdogs. it would be about a 350yd sight in for my gun.

[KVW]

I agree with lee on this. I shoot competition at 200 yds so when I load develop I test at 200 yds. Don't know if its right but that's the way I do it. By the way, that is one heck of a group your son shot. I got one of my boy's started this year at bench shooting. He'll be outshooting me in no time. Get em started young. That way they won't develop any bad habits like me

[Hotshot]

I think if a load is good at 100 it will be good out to the point it starts to lose stability. combination of velocity and BC determines when that distance is.

On the other hand I've seen some loads that don't seem to work too well at 100 really "go to sleep" at 200 and perform well out to the loss of stability thing happens.
This happens on high velocity 25 & 24 cal. often. Years ago when I read Precision Shooting Mag there were some articles about the 25-06 that highlighted this situation. Always load test a 25-06 at 200 instead of 100 was the solution. I have noticed this in my 6mm-06. Since I only shoot it at very long range(500-800), I load test and zero this rifle at 300 yards. It produces 1 1/2 in groups at three hundred yards with loads that are 1 1/4 at one hundred.

I've also noticed this situation in some high velocity 22's with heavy weight bullets, like a 220 Swift AI. Sometimes it pays to test at longer ranges.

[rayfromtx]

snip Since I only shoot it at very long range(500-800), I load test and zero this rifle at 300 yards. It produces 1 1/2 in groups at three hundred yards with loads that are 1 1/4 at one hundred. snip

uh I uhm err oh never mind.

[huntsman22]

um, me too......ferget it

[Hotshot]

The point is some rifle -bullet combinations don't stabilize at 100 yards but they are stable at some distance past 100, so they don't group well untill that distance where they get stable. This is not ground breaking news.

[WrzWaldo]

I wonder if you could explain the physics of that?

Are you really saying they exit the muzzle not stabilized and then by some magic they stabilize and print repeatable holes in a target?

[Lee C.]

WW, I don't know about the magic part. But i was reading about boattail bullets and how they needed alittle distance to get there optimal spin. Or what they called the bullet going to sleep like Hotshot said. Now this was comeing from some of the top shooters on 6mmbr. I didn't see any one disagree with what they were saying. So i think ya got to kind of take them at there word.

I know it's not all boattail bullets as my 40gr. berger bullets will print some pretty nice groups at 100yds. If this is not so i hope some one jumps in here to straighten this out.

[doctor duck]

I might be wrong, probably am but, if you shoot a 1.25 inch group at 100 yards this same group moved out to 300 yards would measure 3.75 inches. I can't figure out how a load that produces 1.25 moa at 100 yards produces .5 moa at 300 yards. I wish someone would clear this up for me.

[jo191145]

This theory of the sleeping bullet made the rounds on the forums about a year ago. Probably the year before that and the year before that.

First off, I'm not a long range shooter. My neck of the woods has no long range ranges.
However theres a group of folks who believe in the sleeping bullet and theres a larger group of people who don't.
Personally I fall into the last group.

If any one can explain to me how an unstable bullet magically understands where its supposed to go at 300yds and beyond but can't get it right at 100yds I'll reconsider.

I've read the theory that the flight path is corkscrewed until the bullet "goes to sleep"
I sincerely doubt thats possible. Even if it were the bullet would need to correct its flight at exactly the same moment and position in the corkscrew to create a tighter group at longer ranges. Now that would surely be a magic trick.
It might be possible for the yaw angle to be larger at close ranges but the projectile must still be spinning on its axis and traveling in a normal ballistic arc.

Clover shooter
You can pat your son on the head for that one
There are loads that shoot well at 100yds but fall apart at long ranges. Your extreme spreads will play a big role in that.
I've seen on numerous occasions the 204 bughole at 100yds with extreme spreads of over 100fps. Logic tells me that would ruin a group at 600yds.
On the other hand if its not grouping at 100yds its not going to get any better further out.

Bergers have always been my favorite but you might want to give the 39bk's a shot. If you can get them to group as tight as the Bergs at close range they should do better at the long ranges due to their superior BC.

[heikki02003]

As jo191145 said, that's some fine shooting.
It's kinda nice timming that this conversation is taking place. I have been thinking and reading a lot about this lately because of my little problem. In no way am I a physicist or a balistics expert, so take my thinking however you will.

I have been resonably happy with my load at 100 yards. If I did my part I didn't have any signs of either vertical or horizontal stringing. Well last night I shot the 200 yard target above and noticed some vertical. Now, there are MANY reasons for vertical, the list is as long as my arm and include both body mechanic and load variables.
The point I am trying to make here is that my vertical did not become apparent to me until I shot a group at a farther distance. I did not see any signs of vertical in the gopher field because 0.7 MOA at 200 yards is not bad, definitely a small enough group to hit a gopher at 200 yards. But the point is to always strive to make things better, right? What I will do now (testing at 200 yards) is try four small things; change primers and see if that helps, try 0.1 grains of powder above and below my load (27.0), try very small seating depth changes, and try a different size bushing in my sizing die (varying neck tension). If none of this helps then I know it's my shooting.
Distance exagerates problems. Plain and simple. Distance exagerates shooting performance and firearm accuracy. What might look good at 25 yards, might not look so good at 250 yards. Guys that shoot 1000 yard F-class and win shoot one holers at 100 yards, just look at any of their load development targets. When a bullet leaves the muzzle, it follows a given trajectory (regardless of rpm). It does not start out going to the right (let's just say), then curve back to the left. Nor does it start out to low, then gain elevation. It follows a straight line trajectory. Yes, it does take some time for bullets to stabilize, but this distance is well under 100 yards. I'm talking here bullet stability, not up or down and right or left variances in trajectory. Bullets have to overcome the disruptance of air at the muzzle from the blast. And yes, once bullets loose rpm and velocity they do become unstable. It is a well know fact that bullets must remain above the speed of sound. The .204 at 1000 yards is not supersonic by the way. For it to be possible you would need a 50 grainer leaving the muzzle at 4000fps (good luck).
Doctor duck I don't think your wrong. It's a matter of simple physics. The only explanation I can imagine for a better group at 300 yards than at 100 yards is the shooter. Think for a second about the golfer who makes a beauty 300 yard drive over water and between two bunkers, then totally muffs a flat 3 foot putt. It's a matter of concentration. This is needed right, because it's a longer harder shot? It is very possible that one would take more time in set-up, make extra sure the sight picture is right, and really make sure the shot is broke perfectly at real long yardages. But then we need to take into account the wind, if someone doesn't read the wind at all, a group will definitly get larger as distance increases.
One last quick example. I'm an archer so to tune an arrow we shoot it through paper (to check for stability). That works for archery, but what I'm about to propose for a bullet is not actually possible unfortunately(because of disturbance). Imagine three sheets of paper at the same height, one at 100yards with a target on it, one at 200 yards, and one at 300 yards. Now shoot a 10 shot group at the 100 yard target that passes through all three sheets of paper. You will see a group in all three targets, and be able to follow each bullets trajectory. You would see each bullet incrementally get farther away from an imaginary centre (the "centre" of the group shifts because of trajectory). For the inverse to happen, a bullet would have to curve in the air, indicating some major major problems. The ones leaving the muzzle heading right of centre would have to curve left eventually to tighten up the group. Absolutely not possible. As I said earlier, distance exagerates problems.

[WrzWaldo]

If a bullet is not stable when it leaves the muzzle then it won't be stable at 200, 300, 400, 1000, 2500... yards. The reason it seems a boattail "goes to sleep" and performs better at longer ranges is because they were designed to be shot at longer distances. The boattail by virtue of it's design has less wind drag (and a higher BC) over a longer distance. Why one BT shoots better at shorter distances than another is most likely attributed to the length of the bullet. I can get pretty good groups with the 40 grain Nosler out of my 1:12 barrel, but the slightly longer 40 V-Max will not group worth a darn (at any distance). If this "sleeping bullet" theory was ever taken seriously why has there not been any published data? If anyone knows of any reputable testing that was done and has a link to the test data I'd sure be interested in reading it.

WW

[jo191145]

heikki

I have to admit I never tried much primer switching until just recently. I was amazed at the difference a primer switch could make in all my loads not just the 204.
I just shot an Audette ladder yesterday with my new tube and 39bk's. This morning I shot five rds of each in the two nodes I found. Pretty much looks like your group but with fewer holes.
Before I do any powder/seating changes I'm going out this afternoon with the different primers I'll pick the best primer first then begin tweaking the load from now on.
I guess I always figured if I developed a load with a certain primer thats as good as it was gonna get. I was wrong.
FWIW thats the type of groups I always get with the 39bk's at 200. I haven't really gone out of my way to force them to shoot though. I usually find a load quickly with Bergers that out shoots the 39's.
Add to that the fact most of my old barrels would blow up the 39's and bullets not reaching the target is something I cannot tolerate.

I've found seating depths can help change both horizontal and vertical. Not as much in the 204 with its long jump to the lands but it can be easily seen in any rifle loading near or in the lands.
Most shooters hate vertical. I love it seeing a straight vertical line on the target. Straight vertical on the target and push the pill .005 closer/deeper into the lands and the vertical disappears. The 204 does not usually live by the these rules though.

WW
Run a search on Benchrest Central, other forums or plain old Google on "sleeping bullets" and you should be busy awhile.
I seem to recall links to articles explaining theories on the subject.
For me anyway logic dictates it just can't happen.
I might be able to fathom the yaw being greater at close range then settling down but that can't have a positive effect on group size at any range. Negative effect maybe.

I do recall someone using an arrow as an example of increased yaw at close range. (heikki, you still paying attention)
Now I've seen arrows wobble/yaw coming out of my compound bow that settle down in flight.
Of course I can't hit a barn with an arrow. Haven't pulled it off the wall in fifteen years. Arrows are to darn expensive nowadays to be losing them like I do.
?????heikki??????

[WrzWaldo]

jo191145

I have googled it numerous times and read the posts over at BC.


Here are some of the top returns on "sleeping bullet" (nothing relevant up to page 5 where I quit looking).