I am not too sure where it came from but at the back of my mind I have the guidance figure of 3 - 4 pellets of sufficient energy as a guide to reliable breaks. An oft repeated "statistic" and one backed with little hard evidence.
When I am assessing a pattern quality this is the pattern density I look for - but this is purely anecdotal. I know what you are saying as I have done the same. However, when you look at a statistically significant sample of patterns (say, 10 for any given set of factors) with real analysis capable of predicting the probability of various numbers of pellet hits at various pattern radii and various clay orientation you will find that you need an incrediably dense pattern. The alternative is to recognize that targets are getting broken by fewer than 3-4 pellet hits. And, that begs the question of, "What is the probability of one pellet hits yielding breaks?"
The dome of an edge on target is obviously a tougher structure to break than the thin underbelly of an overhead target as any trap shooter will testify - hence the need for bigger - higher energy pellets. Maybe yes, maybe no. We need some research on this. The dome may/seems to be soft enough for penetration without fracture.
So what is the relevance of single pellet strike performance – unless it is to test batch to batch consistency of the clay targets. I know we are always grateful for the odd single pellet break but I don't think we should be using this as the standard. No, but we do need to understand the role of single pellet breaks in scores. If we can understand it, we may be able to recommend differing loads for improving scores.
How you set up a test rig for a 3 or 4 pellet strike at 30 yards I am not to sure - it would need a bit of thinking about!! Glad to have you thinking about such testing.
John
