Cooling Jacket has the same downside as Improved Rifling in max bloom, but the side effect of having an increased firerate is that there's less time for bloom to recover, leading to effectively "more" bloom per shot. For example, on the N-TEC it blooms 0.65 with each shot and normally recovers 0.35 by the next shot, but with CJ3 it only has time to recover 0.3, leading to the next shot being 0.05 more inaccurate than standard despite no direct change to bloom per shot.
It's logical that increased fire rate leads to less bloom recovery time, but are you saying that CJ has no effect on bloom magnitude itself? e.g. a full auto stock NTEC would have the same bloom characteristics as a CJ3 NTEC tap fired at the same fire rate.
It seems you have different opinion to @Hexerin on this.