Distance question
- Thread starter St Pauli
- Start date
Mystic Precision
CGN Ultra frequent flyer
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- Summerland, BC
What are you loading and what type of rifle are you loading for?
50m may be just fine for a 45LC lever action rifle.... not so good for a 338 Lapua.
More info...
Jerry
50m may be just fine for a 45LC lever action rifle.... not so good for a 338 Lapua.
More info...
Jerry
If you mean testing for pressure and velocity and not blowing up... 50 is fine.
But for trying to measure any kind of accuracy, no. I find 100 is useless for determining accuracy at 500 and 1000. At best, it suggests loads to investigate.
But for trying to measure any kind of accuracy, no. I find 100 is useless for determining accuracy at 500 and 1000. At best, it suggests loads to investigate.
Some of you people seem to be greatly over rating the effects of distance. Like many of you, I often put an aiming mark on something at about 25 yards, to get an idea of where the bullets will land.
I don't ever recall seeing an elongated hole at 25 yards, from a wide variety of calibres and many types of hunting or target type bullets, meaning all my bullets have stabilized at 25 yards.
I don't ever recall seeing an elongated hole at 25 yards, from a wide variety of calibres and many types of hunting or target type bullets, meaning all my bullets have stabilized at 25 yards.
The bullet is either stable or unstable. If the latter, there is no doubt. Some bullets will print sideways.
When a bullet exits the muzzle, it wig wags a bit. It takes awhile to spin true. This has no effect on accuracy, and it takes a close eye and quality paper stock to discern the slight wig wag. In the early 20's Mann ran tests with the bullets passing through a series of targets, and he was able to measure the wig and the wag. It was usually gone by 50 and always gone by 100.
The Bullet's Flight From Powder To Target: The Internal And External Ballistics Of Small Arms (1909) A good read.
The wig wag means nothing in the real world, except for testing bullets. If you want to see how a bullet performs, say by shooting it into wet phone books (do they still make those?) you should shoot them at 100 yards. The velocity will be more like what you hit a target at in the filed, and most important, you want the bullet not to hit slightly sideways, as it would at 25 yards. This tends to blow bullets up or prevent proper expansion.
Stability (spin rate) must be adequate at the muzzle, other wise the bullet will tumble. And once it tumbles, it will never recover. If it is stable at 10 yards, it will always be stable, because it gains stability as it goes down range. As it slows down there is less air compression, so the less dense air requires less RPM to be stable. Since the RPM does not slow nearly as quickly as the velocity, the bullet gains stability.
Mann knew all this in 1905.
When a bullet exits the muzzle, it wig wags a bit. It takes awhile to spin true. This has no effect on accuracy, and it takes a close eye and quality paper stock to discern the slight wig wag. In the early 20's Mann ran tests with the bullets passing through a series of targets, and he was able to measure the wig and the wag. It was usually gone by 50 and always gone by 100.
The Bullet's Flight From Powder To Target: The Internal And External Ballistics Of Small Arms (1909) A good read.
The wig wag means nothing in the real world, except for testing bullets. If you want to see how a bullet performs, say by shooting it into wet phone books (do they still make those?) you should shoot them at 100 yards. The velocity will be more like what you hit a target at in the filed, and most important, you want the bullet not to hit slightly sideways, as it would at 25 yards. This tends to blow bullets up or prevent proper expansion.
Stability (spin rate) must be adequate at the muzzle, other wise the bullet will tumble. And once it tumbles, it will never recover. If it is stable at 10 yards, it will always be stable, because it gains stability as it goes down range. As it slows down there is less air compression, so the less dense air requires less RPM to be stable. Since the RPM does not slow nearly as quickly as the velocity, the bullet gains stability.
Mann knew all this in 1905.
The one effect I found from testing at 50m rather than 100m is that if I try shooting my usual 10-rounds group for accuracy tests, it's actually harder to measure the results at 50m because I'll get too many "ragged holes" from 2 to 3 moa groups.
On the other hand, I found some combo of bullets and powder charges that are so inaccurate that I had to get back to shooting at 50m just to get the majority of the holes on as 18" square paper! So both distances have their place for me. 50m for the initial shot to see how the load works, and if it's reasonably good, 100m for the accuracy tests.
Mind you, I'm shooting 9mm and .357mag right now. If I was shooting, say, .308, I'd really want to do tests at more than 100m, too.
On the other hand, I found some combo of bullets and powder charges that are so inaccurate that I had to get back to shooting at 50m just to get the majority of the holes on as 18" square paper! So both distances have their place for me. 50m for the initial shot to see how the load works, and if it's reasonably good, 100m for the accuracy tests.
Mind you, I'm shooting 9mm and .357mag right now. If I was shooting, say, .308, I'd really want to do tests at more than 100m, too.
