Shooting 500 Meters is a #%@&*

[Bart B.]

Here's some comments on some posts' sections in this thread....

1858 says:

Anyway, assuming a consistent hold on the target (big assumption), the deviation in elevation should indicate the rifle's and the load's accuracy potential since crosswind shouldn't affect elevation (do you agree with this Bart?).

I agree, as long as the wind speed doesn't reverse or change speed very much. High power rifles have a small amount of vertical shot displacement in cross winds. It goes from 9:15 on the clock with a right hand twist and wind from the right to 3:15 with a wind from the left. Typically not seen unless a 5 mph wind shifts from one side to the other. It's about 1/4th as much as what rimfire 22 rifles have.

The most accurate barrels I know of that shoot 168's through 180's from .308 cases have 1:12 twists. 190's and 200's need a 1:11 twist for best accuracy. 150's up through 165's do well with 1:13 twist. But it takes a 1:9 twist for 220's and a 1:8 twist to do well with 240 and 250 grain bullets. Any bullet spun faster than what's needed to stabilize it will probably not shoot too accurate as they're all unbalanced to some tiny degree and the centrifugal forces created will make 'em jump too far off the muzzle axis when they leave the barrel.

Powders; IMR4064 has shot the smallest 600 yard groups with 168's up through 190's in .308 rifles. Varget may well be best for bullets in the 150-gr. range but IMR4350 works wonders for 200-gr. and heavier ones.

And milder primers tend to shoot the most accurate even if they're not as uniform as hotter ones might well be. They cause the bullet to be more gently pushed into the rifling without deforming it instead of slamming it in with enough force to deform/unbalance it as the bore swages its diameter down.

One can test long range loads at 100 yards but be aware they open up 5 to 10 percent each 100 yards further down range. It's a myth that some bullets/rifles shoot smaller MOA groups at longer ranges compared to shorter ones.

 

[Mr. Bojangles]

There's no shame in your game. Shooting at long ranges is disproportionately difficult, for example moving from a 100 yard target to a 300 yard target is much easier than moving from 300 yards to 500 yards. :banghead:
It never hurts to keep practicing, though.
I work with a guy who says he goes deer hunting at 500-600 yards . Yeah, right.

 

[Bart B.]

MarineOne, your comment:

On the first target (left side) you've got 3 shots almost straight up and down. This shows how your breathing was affecting your shots.

...is of some interest.

How do you know the vertical shot stringing for those three was due to his breathing and not caused by muzzle velocity or ballistic coefficient spread?

 

[MCMXI]

One can test long range loads at 100 yards but be aware they open up 5 to 10 percent each 100 yards further down range. It's a myth that some bullets/rifles shoot smaller MOA groups at longer ranges compared to shorter ones.

This is good to know .... I've had a number of "experts" at my local range and matches tell me otherwise and it never made any sense to me. They use catchy phrases such as "the bullet hasn't gone to sleep yet". My current .308 load will hold 0.50 MOA at 100 yards but as you can see from my target it's close to 0.80 MOA at 600 yards ... that's very close to 10% for every 100 yards (compounded of course).

I'm going to hunt down that IMR 4064 powder and I hope the 178gr bullets work well out of my 1:10 barrel. If a 1:10 twist is less than ideal for a 168gr bullet, then a 178gr should be better although still not ideal. As it is, I'm not disappointed with the performance of the 168gr Noslers.

as long as the wind speed doesn't reverse or change speed very much. High power rifles have a small amount of vertical shot displacement in cross winds. It goes from 9:15 on the clock with a right hand twist and wind from the right to 3:15 with a wind from the left. Typically not seen unless a 5 mph wind shifts from one side to the other. It's about 1/4th as much as what rimfire 22 rifles have.

Thanks for the explanation, I've already made a note in my range book.

 

[lykoris]

I understood f-class shooters tested them at 300 yards(e.g on a new barrel) and for a given calibre already had an idea of the fps they were looking for so for load development it was more shooting over a chronograph in working the load up

 

[Jim Watson]

There was a guy on the benchrest board who set up one of those Oehler Accoustic Targets at 100 yards and a paper target at something over 300. That way he could plot the same bullets at two different ranges, no statistics involved. He said he had never ever seen a group that was smaller in MOA at 300+ than at 100 yards. I consider that a strong indication that the "sleepy bullet" theory does not hold water.

I did some shooting with my BPCR at 200 metres yesterday. I would have preferred 300 but did not think the spotting scope would resolve .40 holes that far away on a rather foggy morning. I wanted to plot each shot in order so as to track the buildup of fouling. Turned out that the first two shots from clean and cold were meaningless on elevation and chasing the spotter before the barrel is warm and fouled is a waste of effort. Pretty close on windage, which is an even stronger factor at 1200 fps than 2700.

 

[Jayhawker]

I set out to find some Sierra 168s. It's a little like looking for primers. After going through all the usual on-line retail outfits as well as stores within driving range (few and far between out here), I resorted to calling Sierra and ordering a box of 100 from them. I won't tell you what I had to pay for buying from them directly but if I did it again, I sure the hell wouldn't tell anyone I did. To give you an idea of how tight things are, I got the last box they had on the shelves.

In any case, the tech there suggested RL-15, 4064 and 4895 in that order. He also said it's their policy to hold seating depth to no less than .010" off the lands although I'm well aware that every rifle will be different in it's preference. I'd like to know what other posters are doing in this regard. He agrees with posters in this thread that a 168 "should", given all things equal, shoot a smaller group at a given range with a 1:10 twist but also says that he's seen many rifles that have their own preference and it just could be that mine "likes" the 150s regardless of the twist, range or otherwise. I believe,(not positive on this) that I read in this or another forum, that Zac Smith shoots a lighter bullet at distance as well. The Sierra tech also said that his own preference for load testing, was 200 yards.

So I'm going to get some brass worked up. Those 168's should be here in a couple of days since they're just over the Kansas-Missouri border from me.

 

[lykoris]

That is interesting Jim.

I'd asked the question what makes a rifle f-class material and was told that you need to see how it groups at 300 yards and the result is a good indicator of how it will perform at 1,000 yards - shooting strings at 100 yards isn't beneficial.

 

[Bart B.]

For all the sleepy folks 1851's referring to when he says: "They use catchy phrases such as 'the bullet hasn't gone to sleep yet.' " Ask those sleepy folks how in the dickens does the bullet know which way to change directions when it does go to sleep. If that sleeping bullet can figure out where it is in an imaginary group plane at a shorter range then change direction such to get back closer to center down range, then one of the "mysteries" of ballastics will be solved.

More explicit, ask one of these "sleeping bullet experts" how all the bullets low and to the right change directions opposite those up and to the left to get back towards center. I've asked this for decades and nobody's even tried to explain it.

This aside, most bullets will cone or nutate a bit after leaving the barrel, but they stabilize well by 100 yards down range. But their direction doesn't change. They can only change direction by the application of some external force such as wind.

 

[MCMXI]

Jayhawker, I wish you'd ordered the Nosler 168gr Custom Competition HPBT bullets from Midway $190/1000 ... a way better deal than the Sierra MatchKing bullets. I used to only shoot Sierra bullets but this year switched to A-MAX and Nosler with ZERO regrets and no deleterious effect on accuracy.

http://www.midwayusa.com/viewProduct/?productNumber=1758477639

Bart and Jim , you realize that I'm 100% in a agreement with you that this "sleepy bullet" theory is BS? I didn't believe it then and I certainly don't believe it now.

Bart, I just want to say that you're a breath of fresh air with your "tell it like it is" approach to long-range shooting. There is so much BS and just plain misinformation on the internet. I think if you keep chipping away at it we might all learn a lot and hopefully new shooters will be encouraged rather than intimidated.

 

[lykoris]

It's a myth that some bullets/rifles shoot smaller MOA groups at longer ranges compared to shorter ones.

this seems logical to me. I have never heard of the 'sleepy bullet theory'.

I have a belief in the point I made above though...it seems plausible. He said a lot of guns will shoot 1moa or even .5moa at 100 yards but you cannot extrapolate that out to 1,000 yards and expect the same. And for that reason he said shooting at 300 yards gives you an indication of the potential at longer ranges 600 - 1,000.

I'm very interested.

Also what is the interest to f-class shooting 100 yards unless fire forming brass / chronograph work in working up a set velocity on a new barrel ?

 

[Jayhawker]

1858: They are out of boxes of 100. If they did not shoot in my rifle, I'd be left holding the proverbial bag if I'd bought a 1000. Thanks for the heads-up anyway.

 

[Bart B.]

Jayhawker's comment on Sierra's tech rep:

He agrees with posters in this thread that a 168 "should", given all things equal, shoot a smaller group at a given range with a 1:10 twist but also says that he's seen many rifles that have their own preference and it just could be that mine "likes" the 150s regardless of the twist, range or otherwise.

...is of some interest to me.

I used to shoot high power rifle matches with Sierra's ballistic tech who tested most of their bullets at their California plant from the early 1950's to the mid 1980's. He also was one of the best high power match/long-range rifle shots on this planet. In one of the tours he gave me "behind the scenes" at their plant, he mentioned the barrels they tested their 168 and 180 grain HPMK bullets with were 1:12 twist as that's what he got best accuracy with. The best of these would shoot 1/10th to 2/10ths inch one ten-shot group after another at 100 yards.

Interesting indeed that Sierra's rep says a 1:10 twist would be good for 168's at "a given range." Considering the fact that for 50 years, the 150-gr. spitzer bullet in the .30-06 cartridge in Garands and machine guns with 1:10 twist barrels originating from the .30-03's 210-gr. round nose bullet spun them too fast for best accuracy. Leaving a bit slower in the 7.62 NATO, these bullets did much better accuracy wise, from the 1:12 twist barrels the new cartridge standardized on. But the .30-06 did very good with the 172-gr. FMJ boattail bullet which was standard from the mid 1920's to the late 1930's in the 1:10 twist barrels it was shot from.

And also the rep's other comment:

He also said it's their policy to hold seating depth to no less than .010" off the lands although I'm well aware that every rifle will be different in it's preference. I'd like to know what other posters are doing in this regard.

Most rifles shoot best accuracy wise when the bullet's seated against the rifling. This does two things quite uniformly; one is to present the same resistance each time the bullet gets pushed into the bore and the other is to center the bullet in the bore when it's fired. One needs to be careful as if you have to unload a live round, you don't want the bullet to get stuck in the leade. Sierra's always shot their test loads with the bullet backed off a few thousandths from the rifling, but they still shoot very, very well indeed.....with full length sized cases; something they've done since the early '50's.

lykoris asks:

Also what is the interest to f-class shooting 100 yards unless fire forming brass / chronograph work in working up a set velocity on a new barrel ?

To me, it works for getting a zero. There's little difference in accuracy between new cases and those fired then full length sized; either is typically better than any version of neck sizing. Proper tests have proved this over the years. I've never got concerned about muzzle velocity; rarely measured it on someone's chronograph as I've never owned one. I don't care how fast the bullets get to the target; just how close together their holes are in it.

 

[lykoris]

There's little difference in accuracy between new cases and those fired then full length sized; either is typically better than any version of neck sizing.

that's interesting also.

I was under the impression fire forming your (new) brass to the chamber of your rifle was an integral part of accuracy, neck sizing and annealing only thereafter

 

[.38 Special]

This is good to know .... I've had a number of "experts" at my local range and matches tell me otherwise and it never made any sense to me. They use catchy phrases such as "the bullet hasn't gone to sleep yet".

In my experience, this -- and the "MOA at 200 but not 100 or 300" business mentioned by "King Ghidora" a page or so back -- is usually the result of scope parallax.

 

[Deckard]

I haven't tried shooting at 500 meters (it might not do my ego much good). I don't even think there is a range that big in my area.

 

[Jim Watson]

shooting strings at 100 yards isn't beneficial.

I think the point is that if you are at the "one ragged hole at 100 yards" level of accuracy, the differences may not show up. A master class friend shot some of my ammo and said that it was undistinguishable from his at 100 yards but showed more vertical than horizontal at 600 while his was shooting round groups. He thinks my powder charge of 44 grains, - 0, +.1 (Varget, with 175 gr Sierra) based on the way I run my PACT dispenser and scale is not good enough, that he gets his dead on to the same tenth of a grain.

He does a lot more brass prep than I do and I wonder if that might not make more difference.

 

[Bart B.]

Jim Watson comments on his master class friend's powder charge weights:

He thinks my powder charge of 44 grains, - 0, +.1 (Varget, with 175 gr Sierra) based on the way I run my PACT dispenser and scale is not good enough, that he gets his dead on to the same tenth of a grain.

Don't let your friend read this, Jim; he'll think you're crazy for even mentioning it.

Back in 1991 when a few of us former US Palma Team members were developing loads for Sierra's prototype 155-gr. Palma bullet, we ended up using 45.3 grains of Varget metered into new cases primed with Fed. 210M igniters. Charge weight had a 3/10ths grain spread and bullet runout was up to 3.5 thousandths. 20 rounds were taken at random from the Dillon 1050 progressives loading that stuff and tested for accuracy at 600 yards. All twenty went into 2.7 inches. So much for having to have tiny, near zero, spreads in powder charge weights.

When several thousand rounds of that ammo was shot later that year in an intenational match with top long range folks attending from all over the world, I asked a few dozen of them what they thought the accuracy was at 600 yards. All sorts of barrel lengths, bore, and groove dimensions were used. They all said about 3 inches. So much for the belief that each barrel has to have each load tailored to it.

The best lots of 7.62 NATO M118 match ammo used in the National Matches tested about 6 inches at 600 yards with a couple hundred shots per test group. Not too shabby at all for those not so good 172-gr. FMJ boattail match bullets. And with charge weights having 3/10ths grain spread at that. Accuracy of the M852 round with Sierra 168's was somewhat better but charge weights varied the same amount.

 

[Bart B.]

King Ghidora adds:

I'm not even sure how people know how to tell when their heart is beating. I'm sure that would be an advantage at long distances though. Maybe that's why I never could match what others do.

The only advantage a beating heart has is it keeps your brain alive so you can shout with joy when you do good. Otherwise, it's a disadvantage to any shooting because it makes your sights bounce around on the target.

First time I ever laughed about it was at the Nationals years ago when doing laundry in town. A world class 300 meter free rifle shooter who had just won a big match in Arizona several months earlier, walked in the laundromat to wash her clothes. I congratulated her on the recent win then she said: "Thanks, but it was almost impossible." I asked why then she replied: "Well, I was fighting two beating hearts; not too good when you're 7 months pregnant trying to shoot a good score standing up on your hind legs." We both laughed about that.

Shooting prone slung up to a rifle with a scope, the crosshair's bounce up and down in a figure 8 (or something close to that) pattern about three times as tall as it is wide. Best way to get the area it covers as small as possible is to adjust the position of your elbows and legs as well as the angle your spine is to the line of sight until that "wobble" area is minimized. You can do this in your home aiming at the door knob on your neighbor's house across the street.

The folks who shoot the best scores laying on their belly have a wobble area about 3/4ths MOA and get shots off inside a 1/2 MOA area inside of that. Once they've mastered the position and get into it the same each time, they'll shoot the same scores with aperture sights as they do with scopes when the wind's calm. This happens because the rifle bounces around the same size wobble area regardless of what sights are used.

Using a scope has the advantage of letting you see mirage (heat waves) wrinkle across the field of view when it's focused part way to the target. Parallax doesn't exist when ones eye is on the optical axis with the scope "short focused" this way and is easy to do if the stock's cheekpiece is set correctly. When the mirage showing what the wind's doing picks up or drops off, you can hold off a bit to one side and still keep shots deep in the middle. You can't do this with aperture sights. You have to leave the sights to look through your short-focussed spotting scope to see the wind (mirage) change.

In a team match using aperture sights, you can favor one side or the other of the target's bullseye as the coach tells you. He's watching the mirage through his spotting scope and tells you what to do; you'd better do it, too. If your front aperture sight's got a spirit level on it (very important for long range) and you know where to put the bubble by canting the rifle to make a 1 MOA windage correction by doing so, that's easier and more precise than holding off. I've done this several times making 1/4, 1/2, 3/4 or 1 MOA windage adjustments without having to take my hand off the trigger/grip to crank the knobs. 'Tis fun to do this with the rifle canted and the front sight bubble way off to one side and nail the bullseye dead center.

 

[Jim Watson]

Doesn't canting the rifle affect elevation, too?

 

[MarineOne]

How do you know the vertical shot stringing for those three was due to his breathing and not caused by muzzle velocity or ballistic coefficient spread?

I've spent too much time on a 500 yard/meter line with an M16-A2 shooting on the old Marine Corps "KD" course and saw it with my own breathing pattern. With irons I was shooting about 2.5 to 3.5 MOA with standard M855 green tip, so hitting the man sized target at that distance was easy for me. Out of the 30 times (5 days a week, 6 weeks) I visited that line, each time 10 shots were fired (300 rounds not counting alibi's) I only dropped 3 rounds.

Plotting and calling each shot was manditory in your range book and for me it really helped with my shooting with stuff like keeping track of breathing, temps, wind direction and speed, visibility, etc..




Kris

 

[Howard Roark]

Doesn't canting the rifle affect elevation, too?

Yes. Cant right, shoot right. The impact will travel in a downward arc in the direction of the cant.

 

[Bart B.]

Canting the rifle will cause both horizontal and vertical shot displacement from the point of aim. Grade school math explains how much there really is. The horizontal amount for a given range equals the cant angle's sine times bullet drop; vertical amount is the angle's cosine times bullet drop.

For example, an original 155-gr. Palma bullet drops 110 inches at 600 yards and 410 inches at 1000. Here's the results at both ranges for a 1 and 3 degree cant:

600 yd.;
1 deg. horizontal = 1.9," vertical = .002"
3 deg. horizontal = 5.8," vertical = .150"

1000 yd.;
1 deg. horizontal = 7.1," vertical = .060"
3 deg. horizontal = 21.5," vertical = .560"

You'll never see any vertical change. A 5 deg. cant at 1000 yards will move the bullet 36" to the edge of the 6-foot wide target and vertical change will only be 1.5 inches; not enough to easily resolve considering the accuracy one gets that far away.

 

[Bart B.]

MarineOne, your comment:

I've spent too much time on a 500 yard/meter line with an M16-A2 shooting on the old Marine Corps "KD" course and saw it with my own breathing pattern.....&.....Plotting and calling each shot was manditory in your range book and for me it really helped with my shooting with stuff like keeping track of breathing,

..are interesting, but we don't know where this guy called those three shots you attribute to breathing. For all we know, he called 'em there. And what about the other shots different positions in the vertical plane; were they caused by breathing, too?

Never heard of "keeping track of breathing." How did you mark that in your range book? "In" and "Out" symbols?

 

[MCMXI]

Back in 1991 when a few of us former US Palma Team members were developing loads for Sierra's prototype 155-gr. Palma bullet, we ended up using 45.3 grains of Varget metered into new cases primed with Fed. 210M igniters. Charge weight had a 3/10ths grain spread and bullet runout was up to 3.5 thousandths. 20 rounds were taken at random from the Dillon 1050 progressives loading that stuff and tested for accuracy at 600 yards. All twenty went into 2.7 inches. So much for having to have tiny, near zero, spreads in powder charge weights.

Bart, so how many PALMA shooters are using that load today? John Whidden certainly wasn't using it when he got the top score of 2232-93 in October of 2005 at the US PALMA team trials shooting a 155gr bullet with 47.0gr of Varget from a 1:10 barrel and weighing every charge on a Denver Instrument APX-200 (a milligram lab scale).

http://www.6mmbr.com/gunweek059.html

So much for the belief that each barrel has to have each load tailored to it.

I think that's an oversimplification at best. I don't think the accuracy of the load you helped develop and tailoring loads to a particular rifle are mutually exclusive. I will readily admit that I can't explain why one commercial load shoots well in a multitude of rifles, I have a hunch but nothing more. But there is no question that accuracy nodes exist for every rifle/load and this is clearly evident to anyone that has worked up a load using an accurate, systematic approach such as OCW.