Anyone try a reflex design on F1 with small venting holes at the rear of the can (ideally venting at 90* rather than straight back at shooter)?  It would seem with a sealed can that the volume reflexed wouldn't do much as the volume has no where to go and any compression of that gas would provide negligible benefit, whereas if there was a small (properly sized) vent(s) somewhere back there it would allow some of that gas to exit the rear of the can as well as via the endcap.

Your inventiveness is applauded.

The idea behind a suppressor is to move gas away from the bore-line so it can expand. Thereby losing its explosive power (pressure), exiting the endcap, and creating less vibration, in the air, which equates to less sound.
The closer you can get the gas's pressure to atmospheric, the quieter the report will be.
The gas escaping that hole will be of higher pressure, than that which exits the endcap.
So, allowing the higher pressure gas to escape will serve only to increase the report (or make a terrible hissing sound)
If you could make another chamber, to bleed this gas into, you'd be far better off.

This is why true reflex designs are far from the 1.5"-2.5" range. The extra volume allows more gas to expand, while also allowing more gas to enter and do the same.




Think of an integral rifle suppressor.


You use the barrel porting, and the bullet as a blocker, to drive those initial, higher pressure, gases into the over barrel/coaxial chamber. Then, allow the baffles, and forward tube volume, to deal with lower pressure.
Integrals are much more effective than reflex designs.

If you could think of a way to incorporate a Klein bottle into suppressor usage, you may have a winner.

I've seen an AAC SCAR HD with holes in the side of them.  From what I've heard it was an end user mod.

Wow, I remember that one
This was done to lower the cyclical rate of the firearm. The proper way to do it, as I've often said, is to modify the rifles gas system, not the suppressor.
The end users were, most likely, Navy SEALs, so I doubt they were the ones putting holes in the cans. It was most likely FN; once they realized their rifles couldn't function properly per the design specs of a military contract.
The suppressors were definitely louder w/ the holes. I'm sure AAC had to take a couple phone calls about this one

Not for long. FN made their own cans after that.

Good find, Villafuego.
Same purpose, different design.
The valve is to relieve excess back-pressure, w/in the suppressors' blast chamber, thereby reducing the rifle's cyclic rate.
If your bolt is traveling too fast, your magazine spring may not be able to compensate, and, upon returning, the bolt will not strip and feed the next round.

This does not improve on the suppressors ability to muffle the report.

What about something like this?

Imagine the shock as the suppressor. Now imagine that inside the remote reservoir is one baffle and a spring and a bleed hole at the far end. With each shot the baffle moves forward to uncover the bleed hole (red dot) at the far end. Once it passes the bleed hole, pressure drops and the spring pushes the baffle back to it's start point.




If the HPA ever passes, I'm going to build this just for fun.

I have a direct reflex mount on order that will mount to the OD of the barrel (which is flutted).  I can shoot it first before I seal up the flutes.