Testing loads at 50m instead of 100m

I’ve been wondering for a while about the difference in testing loads at 50m instead of the standard 100m. I’m an ok shot, not remarkable but ok. When I was doing a lot of shooting (as a youngster) on the local NZDA range my shooting improved dramatically. Now I only shoot when hunting.

It’s made me think that when does the variability of a shooter’s ability (and at my age; eyesight) at 100m override the variabilities in load weights etc when checking loads. Am I better to be testing at 50m and reducing the shooter variability? Just thinking out loud… Cheers

I don't think its a great idea, have seen plenty of loads that look awesome at 50y but at 100y average or sub average, better idea print larger targets rather than shooting closer. During load developement I use a3 sized targets but for zeroing a rifle an a4 is plenty.
My 2 cents

@dannyb Thanks for your input. I haven't handloaded for about 30 years either and always tested at 100m. But I had 20-year old eyes then too ;)

Generally its not a good idea to test under 100y as in many cases the bullet barely stabilized when it reaches 100y.

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Originally Posted by Jaco Goosen

Generally its not a good idea to test under 100y as in many cases the bullet barely stabilized when it reaches 100y.

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Bullets don't get more stable... they are spinning as fast as they are going to spin when they leave the barrel

the argument for first sighting at 25 yards,given 40 odd years ago by Graham Henry still holds merit.......its only 50 yards return trip to target Vs 200 YARDS and even old eyes can see .30 calibre holes at 25 yards....... if you get near enough to bull at 25...then move to 50 or 75 or 100 you are confirming the 25 yard bit..... the advantage of 25-50-100-200 is the click values are easy to work out..... not so easy at 75-150 and if you seldom shoot past 150 yards...and most of your shots are at 50 yards....it makes even more sense.
I missed twice today at under 25 yards due to piss poor visibility but it shook my confidence.....sighting in ,even if its at 25-50 yards before heading out will mean you are confident your rifle is doing its bit.....I know it makes HUGE difference to my confidence.

I do all my load testing at 50m. I walk there and back. 3 hrs of it easily gives me my 10k steps for the day. Besides, that's what I've got in the way of range availability.

I am inclined to believe that at 50m a given load will have the same windage, i.e. vertical plane accuracy, at any other distance given the absence of any lateral influences, mostly wind. So the issue is then horizontal accuracy or elevation or bullet drop or however you want to think about it.

Of course I'm wrong. A bullet on a course a millimeter off perfect vertical centre will be kilometres off at some point between the end of the barrel and infinity. But I'm not shooting to infinity. More like sub-200m. Definitely sub-300. So the issue becomes what error in windage can I accept at 50m that will still give me a kill at say 200m?

In terms of bullet drop, a ballistics app will give you the trajectory at a zero of 50m, I suspect. Not that I really use one. While I have Strelok Pro and have played with it, my optics are not yet such that it is a real benefit. Nor am I inclined to fiddle with a ballistics app while a deer awaits my shot.

I had to refine my views a little at a recent NZDA range shoot where I was able to shoot my new-to-me 243 at 100, 200 and 300m. I had done my load testing and sighted in at 50m. My shots at 100m were fine allowing for range conditions and my degree of ability with a trigger. All would have handily killed a deer. With a following cross-wind, left to right. 100m held no terrors. At 200m I was shooting 100mm to the right and 200mm low. At 300m I adjusted my scope for windage and elevation using best guess, and aimed high and left. Most of my shots would have hit the deer 200mm to the right of the front left leg between hoof and knee. Which is to say, not at all.

I'm still happy with the load, I have no real reason to change that. What I need is real world experience of where my bullet will land at my chosen shooting distances. And the knowledge to change my point of aim to suit the circumstance. I can't get that shooting at 50m.

So developing a load at 50m is one thing. Applying it in the field is another, quite different thing. I suggest...

Jhon me ol pal.....I will make it really easy for you..... give me a moment and will post up a link (if this tech tard can work out how).

https://www.huntingnut.com/index.php...intBlankOnline


right so go in there and enter best guess numbers..... height of scope above bore is normally 1.5" your velocity somewhere around 3100 fps your BC get out of loading manual with bullets.... and keep changing your zeroed for range till everything just makes sense..... FOR ME ,this programme works well because I can look at the picture/curve instead of numbers

once you have the right numbers in,and know where you want to be zeroed for...look back at what height you should be at 50yards and you should be able to use that from there on in......

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Originally Posted by Micky Duck

once you have the right numbers in,and know where you want to be zeroed for...look back at what height you should be at 50yards and you should be able to use that from there on in......

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You're a gem Micky!

With new loads which isnt that common now for me or when I rescope or begin to think ive bumped something I've switch to 50 yds zero as std as long as the scope has parallax ajustment. A 50 yard zero pushes the point blank range out very slightly by increasing the mrt height. However if you really want to extend point blank range choose a 25 or 30 yard zero.
If you set yourself a 6 inch target zone then as long as the bullets plus or minus 3 inches youll whack whatever you aim at which is accurate enough for most game hunting.
With a 25yd zero with a 223 the bullet will rise up through the zero point at 25 yards (first catch), peak at 3 inches high at 125 yards and drop back through zero at 200yds (2nd catch)and be 3 inches below at 280 yards.
With a 50 yard zero or 1st catch, peak height is .4 inch at 90 yards, 2nd catch is at 125 yds and 3 inches drop is 200 yards
With a 100 yds zero first catch is at 65 yards peak height is not worth worrying about and second catch is 100 yds and 3 inches of drop occur at 190 yards.
So there's bugger all between 50 and 100 as a zero point however somewhere between 25 and 50 yds has interesting possibilities for the shoot n scoot types.

One word of warning completely separate from many aspects mentioned above is that most scopes that don't have adjustable parallax have the fixed parallax st at 100yards.
By load testing at 50 you are introducing potential point of impact error that wouldn't be otherwise present.
There are ways to manage this error but worth taking into account.

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Originally Posted by PerazziSC3

Bullets don't get more stable... they are spinning as fast as they are going to spin when they leave the barrel

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Not so. Whilst they are spinning as fast as they are going to does not mean they have settled into their 'sweet spot' and are fully stable. The distance that starts is a variable that changes with various projectiles and starting velocities. The Mk VII .303 is a classic example with the maximum stabilsation range being from 200 to 900 yards. Ballistics is far from an exact science and is full of variables.

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Originally Posted by gundoc

Not so. Whilst they are spinning as fast as they are going to does not mean they have settled into their 'sweet spot' and are fully stable. The distance that starts is a variable that changes with various projectiles and starting velocities. The Mk VII .303 is a classic example with the maximum stabilsation range being from 200 to 900 yards. Ballistics is far from an exact science and is full of variables.

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Bang on. To reinforce what @gundoc was meaning, check this video: Although on a much larger scale and not an exact comparison, the projectile that leaves the 'tank' is in no way stabilized.

Skip to 6:10

https://www.youtube.com/watch?v=xpJ8EoGmLuE

I'm a strong believer of groups not tightening up at longer range. In practice you might see it but over a large average it's not possible. Unless someone can show me actual scientific reasoning how a bullets pass can change mid air consistently without external forces....

To answer ops question I reckon 50m isn't a good idea as you will possibly be shooting just a ragged hole.

agree,if its 2" at hundred it wont be smaller than 2" any further out....it might stop wobbling around but it wont tighten up. it COULD feasably stop wobbling or cirling around its axis a little so MIGHTNT double group size at double the range,but it sure as God made little green apples CAN NOT suddenly shrink groups by now deciding to change path to where you desire it to be Vs where it was.

If anything I prefer to shoot groups at 200 so I can see any oddities starting to rear their ugly heads
unless they are subs then its 30-40m

Greetings All,
An interesting discussion. I do most of my chronographing and initial load development at 60 metres as this is convenient here. Final zero and testing is done at 108, 172 or 198 metres depending on the rifle and its capabilities. The odd ranges are due to the availability of a bench and backstop at these ranges. We all have an idea of the range that we are competent to shoot at and my belief is that we should validate our trajectory by test firing out to at least 2/3 of that range. The mesage here is that do not zero at 50 metres and pretend you know where your projectile is going at 300 let alone 500 metres. As for groups tightening at 200 metres from 100 metres when measured in moa or mrads I have seen this too often for it to just be chance. One of the factors here may be parallax or the apparent shift of the reticle due to head position. Non adjustable scpoes will have some parallax shift at 100 metres and more at 50 metres.
Regards Grandpamac.

so were these mysterious shrinking groups still centred around the bull or off to one side or higher or lower????
one other factor that comes into play is you are aiming smaller at 200-300 yards and concentrating more as any little shake takes you off centre by twice or three times as much.

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Originally Posted by grandpamac

Greetings All,
An interesting discussion. I do most of my chronographing and initial load development at 60 metres as this is convenient here. Final zero and testing is done at 108, 172 or 198 metres depending on the rifle and its capabilities. The odd ranges are due to the availability of a bench and backstop at these ranges. We all have an idea of the range that we are competent to shoot at and my belief is that we should validate our trajectory by test firing out to at least 2/3 of that range. The mesage here is that do not zero at 50 metres and pretend you know where your projectile is going at 300 let alone 500 metres. As for groups tightening at 200 metres from 100 metres when measured in moa or mrads I have seen this too often for it to just be chance. One of the factors here may be parallax or the apparent shift of the reticle due to head position. Non adjustable scpoes will have some parallax shift at 100 metres and more at 50 metres.
Regards Grandpamac.

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I agree you can shoot tighter groups at distance due to things that have no correlation to ballistics, e.g scope parallax, shooting style, eye sight, target size. Not a bullet suddenly correcting alignment and creating a smaller group

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Originally Posted by gundoc

Not so. Whilst they are spinning as fast as they are going to does not mean they have settled into their 'sweet spot' and are fully stable. The distance that starts is a variable that changes with various projectiles and starting velocities. The Mk VII .303 is a classic example with the maximum stabilsation range being from 200 to 900 yards. Ballistics is far from an exact science and is full of variables.

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Also boattails take a distance to stabilise which is why they are suited to longer range shooting and why benchrest shooters use flatbase at closer ranges. Yes?

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Originally Posted by Jhon

Also boattails take a distance to stabilise which is why they are suited to longer range shooting and why benchrest shooters use flatbase at closer ranges. Yes?

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nope....boat tails are more slippery through the air so hold up better in the wind etc,they are more aerodynamic...flat base are cheaper to make and grip loose n worn bores better and there was a theory they expanded better and held together better in arse end at one point in time...... use what you have on hand,the ONLY advantage to boat tails for the likes of me who doesnt shoot past 300 often,is they are oh so much easier to load into case....I can still miss just as well with them.

Theoretically there is a period of maximum stability for a projectile which depends on its length, rate of rotation and velocity more than anything else.
Think of a spinning top it starts off with a slight wobble then stableises, as it slows at some point it begins to slowly wobble a bit following an arc around the point. As it slows further the wobble gets bigger till it finally falls over same thing with bullets

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Originally Posted by Marty Henry

Theoretically there is a period of maximum stability for a projectile which depends on its length, rate of rotation and velocity more than anything else.
Think of a spinning top it starts off with a slight wobble then stableises, as it slows at some point it begins to slowly wobble a bit following an arc around the point. As it slows further the wobble gets bigger till it finally falls over same thing with bullets

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But if you started a spinning top in the middle of a circle, and it wobbled to the left, it wouldn't then automatically come back to the centre each time

Hi everyone. Sorry for being late returning to the party, but was away for the evening. Just to clarify... I was meaning testing loads at 50m, not sighting in. I do sight in at 100m, but with load testing I was wondering how much variability the actual shooter has at 100m compared to 50m.

I'm sure that many on here are much better shots than me and can shoot more consistently than me. But I was thinking that it only takes a slight variation of the shooter's ability to override the difference in the powder weight when working up a load. For example; I can shoot my 223 more accurately than my 308, as I suppose most can. And my 303's are harder to shoot accurately because the cheek weld isn't as good. All of which is far more noticeable at 100m,

What I was thinking of trying was to work up the loads at 50m and then check the best at 100m to suss a load for good hunting accuracy. My set up isn't a bench rest style of situation, it's lying n the paddock and walking back and forth to check each group. Which again, probably affects accuracy (shooter capabilities).

When sighting in I use the info from the Nikon Spot On programme to use at 100m. I've found it really good. Cheers for all the input.

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Originally Posted by Micky Duck

nope....boat tails are more slippery through the air so hold up better in the wind etc,they are more aerodynamic...flat base are cheaper to make and grip loose n worn bores better and there was a theory they expanded better and held together better in arse end at one point in time...... use what you have on hand,the ONLY advantage to boat tails for the likes of me who doesnt shoot past 300 often,is they are oh so much easier to load into case....I can still miss just as well with them.

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Guess i shouldn't read articles like this one then...:)

"In the images taken during the Guns & Ammo TV test, the boattail projectile is entirely overtaken and surrounded by the propellant gases. This is not the case with the flat base. It is never completely overtaken by the propellant gases. The flat base on the right still has its nose protruding from the propellant gases and the shapes of the blast clouds are completely different. This suggests that the boattail bullet allows more high velocity gases to flow around it in the reverse flow stage than the flat-base projectile.

An additional test was done with the barrel approximately 5 inches out of the field of view of the Schlieren system in order to look at when the two projectiles cleared the influence of the muzzleblast. These images show the flat base clearing the muzzleblast quite a bit sooner than the boattail. In fact, the video shows it takes five frames longer for the boattail projectile to clear the muzzleblast. The flat-base projectile will clearly be influenced less by the muzzleblast than the boattail projectile."

and

"The Schlieren images show that some propellant gases blow past the boattail projectile before it seals the bore. This can have adverse effects on the projectile. The gases that travel past the projectile are very hot and travelling very fast.

Despite how brief this propellant gas blowby is, it can result in non-*uniform deformation of the projectile, or flame cutting, of the jacket. This can result in erratic flight of the projectile and is the cause of the troubling fliers we have all seen in our shooting groups from time to time. I’m not saying these things always happen, but it does create the potential for them to happen.

Perhaps the most important takeaway from this test is the response of the boattail projectile versus the flat-base at the muzzle’s exit. The larger and longer-*lasting reverse flow on the boattail projectile can have a significant effect on its performance. With the sloping boattail, the reverse flow can produce a lift force on the boattail causing yaw and essentially making the projectile wobble. The duration of this lift force is very short, but it can have a significant effect on the projectile’s flight performance. This can cause larger groups and contribute significantly to the time it takes a projectile to go to sleep. Again, I’m not saying this will always occur, but the potential is definitely there. This dynamic condition does not exist with the flat-*base projectile."

and

"As you can see from the images and the analysis, the boattail projectile has much greater potential for undesirable things to happen. The boattail projectile has a greater sensitivity to factors not being perfect, either in the barrel or at the muzzle. The boattail projectile would be more sensitive to a large throat, throat wear, a damaged crown or worn rifling at the muzzle. If you have a rifle that won’t shoot very good groups with a boattail projectile, try a flat-base bullet and see if it results in better groups."

https://www.gunsandammo.com/editoria...ectiles/375628

The real world application of this particularly applies to old battle rifles like the 303B. Most of the reading I've done suggests flatbase projectiles are highly preferred over boattails for the 303B - where "large throat, throat wear, a damaged crown or worn rifling at the muzzle" issues would be pretty common. So may not apply quite so much to the highly tuned close spec target or hunting rifle of today, but still, its difficult to get past the fact of potential gas produced yaw/wobble for a boattail at the muzzle of any rifle as this is a issue specific to the projectile configuration rather than the rifle. Being a legend in my own google-time, this would be why I recollect other references to boattails needing some distance to "settle-down" in flight. But maybe its not so much them settling down as them not being upset further as much as flat bases by other factors such as side-winds.