22 Grendel 40? IMP

[Es 350]

I use Hornady cases and they hover around 34.9 to 35.0 in the .224 Predator.

Edit: The above is after necking down the 6.5 brass but prior to firing. After firing, the brass volume is 35.3-35.4 before sizing.

Thank you!
According to your capacity i didnt really gain that much with my improved version.
Fireformed , resized my case holds 35.7 gr .
Have read on another forum a guy with a 224 Grendel/hornady brass was at 34.2gr.

When I first necked down a few 6.5 Hornady cases i checked the capacity and was right at 34 gr, from my understanding "normal" 224 Grendel/LBC/Predator is a straight necked down 6.5, same neck length etc.
So may be lot#'s of brass.
But with my brass i only have .7 gr more capacity than you with my IMP version.