Gas check?

I am about to start loading for a 454 casull and am looking at about a 290-300 grain Keith style boolit that I plan to push around 1300-1400 FPS. I powdercoat so I am wondering if that will suffice for straight ww or if I need to go with a gas check also. SRH 7 1/2” if that matters. I have good results in the 44 at about 1300 with a 265 grain Keith boolit plain base so I think I might be alright with the 454 at similar velocity. I will be ordering a mold from Tom at accurate molds.

I wouldn't bother with a gas check around 1300-1400 FPS especially if you powdercoat.
I push 377grns in a 50 AE past 1300 fps ++P with no GC

Not as large a caliber, but I've run powder coated bullets over 2000 fps in my M1 Garand with no lube and no gas check-- and no leading or fouling of the barrel.

Good that was what I was hoping for.