Yea, My first try at softening the crack from my BP-17, actually made it louder..! My second try was a modification of the first try. Not much change, still louder than original.
So I went a whole different direction.
The new "chamber" dividers are made up from RC car spur gears, a near perfect fit. The first chamber actually expands as the pressure enters the chamber (note the pen springs)...or at least that was my idea / hope..! There is now a total of five small chambers from the original two. The section on the right screws into the tube and clamps to the barrel. The section sticking out of the left end of the tube, screws in until it hits the all-thread from the expanding section on the right. Then the front end wall (far left) screws in until it hits the three other pieces of all-thread. The white pieces are just silicone tube that act as spacers.
I don't know if it because there is more semi-connected (gear teeth openings) chambers, maybe the expanding chamber actually works...a bit of both. But the overall sound is down, by about a third, at least by my ears, (listening from the same location for each test). But the big thing, the "crack" is all but gone. The sound is now more of a soft thud, rather than a medium crack like it had. I have no real way of checking the sound (db level), but my two cats, maybe five feet away, don't even look up any more..! One thing, the center holes are just large enough for a .22 to go thru without touching. Well, my alignments were "close"...but the last gear (on the left end as shown) got clipped by a pellet...and the hole is now a little larger...and no longer round..!
All in all, about $20 for everything, about two hours of work, and it pretty much does what I'd hoped it would.
Mike
P.s. - No change in accuracy or impact location at the target, and that's obviously a good thing. Even the pellet that clipped the last gear, wasn't off by too much.
