Brass pressure spikes

So a co worker purchased a kimber 7 rem mag and has been working up loads with rl 22 with 175 grain Partition. When shooting Winchester and Remington brass his speed averages 2850 to 2875 both cases. He purchased some Hornady brass and same spec load drives them 3k plus. Naturally shiny head stamp And sticky bolt . Also there is an extremely shiny ring by the belt on the case. Load is 62.2 of rl 22. Not sure what coal is or the jump. I told him to get rid of that brass. Has anyone else had this happen?

He needs to find out what the water capacity of the different brass is. Sounds like the Hornady has less case capacity. That's not really a bad thing, as it will probably have thicker walls, head, etc. But it means that he'll have to adjust his load for that brass.

Using a number of different cartridges I found that Nosler brass gave the lowest FPS with Rem/Win/Weatherby in the middle and Hornady the most FPS.
I figure it is all about case volume.
I shoot max loads and did not have trouble with pressure spikes. You seem to have.
I also found that they shot to different spots on the target opening up groups and SD when shooting them mixed up. Once I shot each make of brass alone I got excellent small groups from each. BUT at a slightly different place on the target.

In my experience, Hornady brass runs thicker resulting in less water capacity. When switching brass manufacturer or even no lot, I make it a point to figure the water capacity and adjust my powder accordingly

Gents thanks for the help