Recent content by Ballisticboy

Slugs do not get more stable as speed increases. In fact, like most spin stabilized projectiles, at subsonic speeds the faster they are fired the less stable they get. Depending on the stability factor of the slug, having less stability may reduce group sizes, but there are plenty of other...

A rebated boat tail is claimed to improve the intermediate ballistics, thus reducing group sizes compared to a straight non rebated boat tail. The main problem with rebates is that they increase the effective boat tail angle, which is already excessive on many slug designs, making it difficult...

Simples. Because I read it on this one first. :)

Approximately 11.7 degrees outside, about 12.1 degrees internally.

Some of the reasons lead free pellets give larger group sizes were discussed here. https://www.airgunnation.com/threads/lead-and-lead-free-pellets.1283547/

Not really semantics, differentiating between the two is very important if you want to understand what is happening. As for the 100 yard groups in any weather conditions, to try to ascribe the differences in group sizes to BC alone is pure folly and is ignoring the most important basic...

You are talking about accuracy, where BC will have an effect. I was talking about group size, or precision in US nomenclature, which is not the same thing as Bryan Litz explains in his book.

Unless you are shooting on a windy day with the wind varying a lot, BC will not help your group sizes, that is much more complex.

Both MERO and the original Chairgun will give maximum ranges.

GA is not a suitable drag function for slugs, particularly at speeds approaching 1000 ft/sec. The BC quoted by FX may well be based on the G1 drag law again not suitable for slugs giving artificially high values at higher speeds, good for sales, not good for trajectory modelling. RA4 is better...

This is why we want the matching Reynolds number where possible. Many tunnels work by using accelerating or slowing air speeds to measure over a range of Mach numbers, trouble is there is something called aerodynamic hysteresis which means you get different results depending on if you are...

If you want to learn how flares stabilize projectiles, look up flare stabilization in any reputable projectile aerodynamics text book. I was calculating and predicting the stabilization of flare stabilized projectiles for 40 years as a gun projectile aerodynamicist, and they all flew as...

You will have to watch your barrel twist rate with slugs. The twist rate will dictate a maximum length for the slugs which can be stabilized. Boat tails make slugs less stable and require a faster twist rate to be stable than the equivalent cylindrical based slug of the same length.

All types of stability, including aerodynamic and gyroscopic stability, are dependent on moments, not forces. The drag force has practically zero moment about the CG, whereas the normal forces produced by the flare when at an angle of yaw produce correcting moments about the CG. Drag has little...

I am afraid you will have to wait a very long time then. I did not suggest that the reports were wrong, just that the pellet shapes chosen led to a biased conclusion. This can be easily seen and checked in the calculated drag coefficients, which are higher than those derived from free flight...