All indoors between my living room and my kitchen, 30 feet, M/L:
I tried those powderless Aguilas in both an 18 1/2" barrel Remington Nylon 66 bolt rifle and a Remington 512 with a 25" barrel.
Both these rifles are very well-used with highly polished bores and in both cases the first shot stuck in the barrel. After getting the bullets out, I ran a dry Boresnake through both barrels, and after that the bullets left the barrels with barely a sound except for the firing pin fall and the noise of the bullet strike against the backstop --the usual cardboard box full of newpapers.
After about fifteen shots for each, I quit, just wanting to get an idea as to where they were shooting, and the bullets were still getting out of the barrels. I don't know for how many more rounds that would be true. There was no difference in impact points throughout this limited testing, as for example, due to fouling buildup.
In both cases the cartridges fed up from the magazines (box in the Nylon 66, tubular for the 512) with no problem.
At this approximately 30 ft. range, the Nylon 66 wanted to place the 20 grain bullets very far (2" or so) to the right, the 512 was pretty much dead on for the sighting for regular .22 LR ammo. I have no explanation for this other than the old saw, "Every rifle is a law unto itself."
I tried one of these powderless rounds in a short barreled .22 pistol, again, inside my house, and the noise was very loud (as someone said, like a firecracker), and made my ears ring. I was quite surprised at how loud it was indoors and quit experimenting with that notion.
I tried the 60-gr subsonics in my Ruger Mark II pistol at the range and was surprised how accurate they were at a whole 15 yards, but they failed to eject (stovepiping) about 10-20% of the time. Something happened to the target carrier motor at that point and I could not experiment with these rounds any more... it was at the end of my regular shooting session anyhow, so that was that. I did not get a chance to test them out of a rifle. With my hearing protection on, I cannot comment as to whether they were quieter or not than regular .22s --they sounded about the same through the hearing protection.
Incidentally, my understanding of where a .22 starts slowing down in a rifle barrel was that it was about 18", but there are enough variables involved (polish of bore, whether you're talking about high speed or standard velocity .22s, etc) that I won't quibble about it --just some additional input on that point.
