Colo32 wrote: I figured there would be a better way to start the cross flow with some geometry easier created on CNC equipment. The ball end mill in the face seems like a simpler solution for the home hobbyist to achieve.
It is easier, but sometimes making things more complicated doesn't improve performance. I've tried some very intricate designs, up to and including machining impellers onto the tip of a cone to reduce first round pop, only to find that tweaking the geometry of a standard cone profile and playing with the clip was more effective. That's why you see the more acute angle with the double clip on the first cone in the image of my Phoenix guts.
One thing that seems to be overlooked in many of the baffle drawings I've seen is that the very high pressure, supersonic gasses present for a very short duration and following a projectile behave nothing like the lower pressure, lower velocity and more constant flows that aerodynamic flow modeling programs are designed for. You have some very interesting phenomena going on with propellant gasses behind the bullet inside a suppressor, many of which are not easily modeled or predicted, which is why suppressor design is more iterative and artistic than it is straight forward engineering.
In general, of course, the goal is to reduce flame propagation & laminar airflow as much as possible. But then there are cases where a balance must be struck, as with semi-autos, where excellent SPL reduction at the mil spec position really doesn't matter if you're far higher at the shooter's ear. Since your host is a blowback carbine, this is an important consideration. On the Banshee, I would wager shooter's ear numbers with most available .45 cal cans are over 140 dBA. Since you indicate that this will be a dedicated can for that host, I would focus on minimizing backpressure rather than maximizing muzzle end suppression.
Colo32 wrote: As far as the length goes, is there a point of diminishing returns that you have experienced with 45 ACP?
I really couldn't say. I've always worked up from the shortest & slimmest dimensions until I struck a good balance betwixt size & suppression, so I don't have any particularly large critters. The biggest diameter .45 cal can I have is my Vorticis, which is 1.5" x8", but it's a rather unconventional critter that was designed to reduce port noise on blowbacks more than chase mil spec position numbers, so it's got a relatively compact baffle stack with a large blast & coaxial chamber, and some other features that focus on minimizing backpressure.
.45 cal is always going to present challenges due to the large aperture, so volume is definitely your friend, and length is more effective than diameter within practical limitations.
