Warning on felt cleaning pellets

havent heard anyone say this, but I just got some air Venturi felt cleaning pellets for my wildcat and found out something quite interesting. Since they are extremely light they are not at all backyard friendly. Took one shot with them and it sounded like I just shot off a .22. They fly supersonic, which kind of surprised me considering how much I assume they tumble. Anyone it did definitely clean out the barrel some. 
 
Mark, a single felt pellet (or multiples) that breaks the sound barrier does so in the barrel and is at its maximum velocity as it emerges from the crown. From there the deceleration is dramatic and it would be subsonic within the first yard or so; and maximum range is about 15 yards. The sonic boom IS CLOSE to you.
Best to use 3 or more at a time depending on your rifle's power.
You can recover them, wash them, dry them thoroughly and reuse them if you wish !!
Kind regards, Harry.
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One VFG .177 felt cleaning pellet weighs approx 0.5 gr.
My old FWB 300S shoots them singly at 906 fps for 0.91 fpe from 18 inches to mid point between chronograph sensors. In that 18" it would already have lost some velocity.
It presently shoots 8.44 gr JSB at 640 fps for 7.68 fpe; so the felts are 266 fps faster at 18".

My guess is that a rifle that will shoot the 8.44s to 15 fpe will have the felts already exceeding sound speed; and probably the sonic crack will be evident at Mach 0.9 pellet speed as the air flow around the cylindrical felt pellet will probably already be Mach 1 or higher.

They certainly crack if I single load them in my HV BR rifle set at 17 fpe with JSB Heavies but I have not measured the felt's velocity. Presently that rifle is broken down for thorough cleaning and lubing . 
In BR comps I occasionally hear a crack on the line when someone puts a cleaning pellet or two through their rifle. ...... Kind regards, Harry.


 
for what its worth I been cleaning my .177 with Q'tips dipped in acetone. I wet both ends and push in by hand then have a length of plastic covered 12/2 electrical wire to push down the barrel. I use 3 or 4 till they come out clean then dap a little lightweight machine oil on just one end of a new Q-tip and leave the other end dry to protect the inside of the barrel. when I do it like this its cheap plus know I did a good job cleaning.
 
I have always used felt pellets to clean the barrels on all my guns. I push them through with a wooden dowel. I just never "felt good" pun intended --shooting them through the gun. I push one at a time, the first two wet with pelgun oil and then push them through one at a time till they come out clean. If Ted says it is alright to shoot them 3 at a time I'm sure good with that. Brian Smith