Powder changing group?

[Pete112288]

So I had not thought too much of it till lately. I have read a couple articles and it has got me thinking. How much can just the brand and type of powder change your grouping? One article showed a 4 inch groups with 777 FFG but then 1.5 inch groups with Geox. I didn't think the powder alone could make such a difference. I know there is really no way to tell until you try it with your specific gun and bullets but I was curious if anyone has experienced this. As an afterthought I just realized when I first started muzzy I was getting 1.5 inch groups at 100 with 777 FFG, then by accident I picked up FFFG instead. My groups grew larger with the same setup when I went to FFFG.
Have you seen any differences?

[lokidog]

Different powders will create different velocities at the same powder volume as well as different fouling characteristics.  This has the potential to change group sizes and impact location.  Even the change from old powder to new of the same kind, I would think, would have potential to change this.

On a side note, I've been the happiest with Triple 7, having also tried Cleanshot, Blackpowder, Pyrodex, and another one or two through the years. I am currently shooting FFF.

Having just reread your post, I see you are mostly asking about the change from FFG to FFFG.  The answer is the same, yes it can.  FFFG will burn faster and give a different velocity than the same amount of FFG.