Strange results when doing pellet tests

[SuffolkRifle]

Hi, got a SMK 25 pistol, and the other weekend, I decided to try a load of different pellets through it, and ended up with some wierd results.
Four types of pellet gave really good groupings in that pistol, but for the life of me, the results just are doing my head in, as there's nothing logical about it!
The four pellet types aren't made by the same people, the prices are at the opposite ends of the scale, so why are they performing so similarily?
The pellets in question are (each pellet type is linked to the target shot)
SMK Spitfires
Marksman Pointed
AA Field 4.51
Daystate Rangemaster Li

Has anybody come across a similar thing, either with the pellets mentioned, or with any other types (other than 'rebadged' ones, obviously), or can anybody give any credible reasons for such results that I've got???

[HW777]

Try shooting a few pellets into some fibre, from a pillow or such like, then look at the rifle marks, you maybe surprised ? but it still wont explain why cheap pellets group well. LOL

[Retracted_Yeti]

What's your problem, use the pointed Marksmen pellets!

Cheers.

Roy.

[SuffolkRifle]

I can get the spitfires cheaper