Assuming that they use their own components and powder, you can look up all the powders that Winchester offers on the Hodgdon site.
https://www.hodgdonreloading.com/data/pistol
None of these powders at their max load approach 1,300 FPS in a 115gn projectile.
This is more of a sub-machine gun load than a pistol load. Similar to "NATO" power... They quote pressure 15% higher than standard velocity 9mm Luger for this new round.
NATO 9mm develops 36,500PSI pressure. Normal 9mm is 34,100 PSI (CIP standards).
Reference to the SAAMI standards show that this round is above _+P loadings...
https://saami.org/wp-content/uploads...sting-Copy.pdf
Here's the Winchester site for the round with a picture of the box:
https://winchester.com/Products/Ammu...uty-/WIN9MHSCL
And discussion of the new M1152 round:
https://www.guns.com/news/2019/11/12...ctive-duty-9mm
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Igitur si vis pacem, para bellum -
- Therefore if you want peace, prepare for war.