Recent content by Ballisticboy

When you have some velocities for one of the projectiles, send them to me and I will use them to derive a drag law which we can compare to your estimates.

Nice video. I wonder how the wasp sting compares to the Box jellyfish sting?

I just looked at the article referenced above. The main thing which comes out of it is how out of touch with the ballistics world the small arms industry has been. Purpose drag laws replaced BC's in the 1960s in the large calibre world with the widespread use of computers. I had not even heard...

There are things that could be done to pellets, or more precisely pellet shaped projectiles, to make them more suitable for long range shooting. Making heavy pellets by putting all the extra mass at the front rather than filling up the flare at the back would help to avoid the dreaded spirals...

Even in external ballistics, the word "precision" has different meanings. What is called precision in the US is called dispersion in the UK, and precision is used to denote the combination of accuracy and dispersion. This is why there have been attempts to define terms in international ballistic...

You should never even think of using these pellets on anything living, the chances of hitting in the right place, even at short ranges, are zero.

I tested some of these in .177 from a 12FPE rifle. They are so light, they had an MV of 990 ft/sec but still only about 8FPE, some may have been higher. The measured BC, when I managed to get two velocities, was 0.0025, the pellet having lost 763 ft/sec in 30 yards. They do make a nice bang...

Was MV really 1364 ft/sec? That is an awfully high MV for that type of pellet. It could also explain the higher BC value as the GA drag law is too high a drag at those velocities, which would give artificially high BC values.

Surface area has very little effect on the drag, as the skin friction drag is only a small component of the total drag. Base drag is the biggest drag component for both pellets and slugs. A cross wind does not push on anything. Down wind drift is caused by a component of the drag of the round...

Regardless of the actual wind speed, if you want to truly compare wind effects you need to fire interleaved serials where you fire one shot from gun A followed by a shot from gun B, then one from gun A followed again by one from gun B etc. until you have fired around ten of each. Then you can...

Pellets, when fired from a right-hand twist barrel, drift to the left, not the right. Your predictions would be in the right direction for slugs or bullets. It would appear that the writers of the software do not know the difference between aerodynamically stable projectiles and aerodynamically...

Sounds good to me. 🙂

I got this in an email from LabRadar yesterday. Labradar V1 $449.95 Demo Labradars Available (Limited Qty) $399.95

Because it is not so much over stability as such. We always used to refer to over stability as when the projectile is so over stable that it cannot turn to follow the trajectory and ends up going sideways due to Magnus forces. That is not happening with pellets, all that is happening is that the...

There are a number of factors, some of which you will not easily be able to get hold of, such as the aerodynamic yaw moments. I am currently looking at the average gyroscopic stability factor, which includes most, but not all, of the relevant factors. There seems to be a small range of values of...