What you're calling a "C-baffle" is generally just referred to as a cone/conical baffle. Lots of variations on cone shape, diameter and taper, but they're heavily used industry wide, much more than K or M baffles. Cut open almost any rifle suppressor, and you'll find cone baffles. I use them almost exclusively, usually with a 60° included cone, larger relative to the baffle OD in your photo, and sans the square stem at the rear. This is the exploded view of my Phoenix XLV .45 cal:
https://imgur.com/5qrYpeK
One of the red anodized baffles for my Ocelot rimfire can
https://imgur.com/iuhtVdG
The 17-4 baffles for a welded core prototype that became my Valkyrie & Furtivus line after some refinement and adjustment of heat treat temperature:
https://imgur.com/6R0iu9c
I have one design with K baffles, and a couple of monocores, but everything else is cone baffle.
Again, it's the most common baffle type I've encountered in any campany's products. Some are stepped, some are clipped, some have a radius, but they're all basically this pattern.
On another note, unless it's to be a lightweight hunting can and you're going to limit your rate and volume of fire to an average of about one round per minute, I wouldn't put aluminum baffles in a centerfire rifle can. Fine for rimfire and pistol, but rifle cartridges generate orders of magnitude more heat and pressure. Put 30 rounds of .22 through a can rapid fire, it's a bit warm. 30 rounds of 9x19mm, it's getting unpleasant to touch for any duration. 30 rounds of 5.56x45mm, the thing is gonna remove your fingerprints instantly. Rapid or full auto fire with a rifle can get a can to >800°F very quickly; Aluminum starts to melt at ~900°F, and even 7075 is quite weak above 300°F. 73 KSI yield strength at room temperature, it's down to 27 KSI @ 300°F and just 6,500 PSI @ 600°F. Exceding 600°F, it's mechanical properties are more like copper and then lead. If you wouldn't use those materials in a suppressor (who would?), then don't use Al in a can that will get that warm.
