I picked up a couple of boxes of Aguila Super Colibri ammo today to see how it fares as an indoor practice round (it's sometimes tough to get out in Indiana winters). If you're not familiar with this stuff, it's basically a 20 gr. .22 bullet fired by the primer in a case that appears to be around the size of a .22 Long. They're rated at around 500 fps.

Noting that the velocity of the rounds is less than that of my pellet gun, and the bullet isn't much heavier, I opted to use my pellet swinging target trap as a test background (with a board behind "just in case"). The box says not to use in a rifle, since the bullets may not exit the barrel, but I chose to try it in my Marlin 39A anyway. Excellent! They're as quiet as a BB gun out of the rifle, and easier on my trap than my pellet gun. Should be a great way to maintain my shooting skills. I also shot a few rounds out of my S&W 617. They're a bit louder and more powerful out of the revolver (about like a cap gun), but still pretty reasonable. I haven't clocked them yet, so I don't know what velocity I'm really achieving.

At $2.00 a box/50, it's a nice way to use "real guns' while keeping out of the cold. :)

Believe it or not, they were first marketed as just "Colibri" (not 'Super') and were even more low powered...those would sometimes stick in a well fouled rifle barrel. The newer (and as far as I can tell, they totally dropped the original loading) have a bit more zip and aren't likely to stick in a rifle barrel (although they might in one of the long 28" versions). Pays to check when you think you've missed your target.

Are great fun...can bring back the fun of a simple plinking session in areas where louder shots would be ill advised.

I knew about the lower-powered stuff (around 300 fps). I wanted the "zippier" version so I could use it in my rifle (24 inch barrel) without worry about the bullets sticking (a closed-chamber .22 rifle with this ammo is extremely quiet). So far so good. I do check to make sure the bullets are exiting, but with the noise of the metallic target it's pretty easy to tell.

The only rifles that would stick CB caps were a couple of long barrel (28" )match guns...tight bores probably increased friction. In sporters or rifles with Normal bore dimentions, haven't had CB's or the Colibri's stick...but when outdoors shooting at things with out a loud back stop, will still check the bore after not hearing a bullet impact.

Not unique to the Colibri...I'd check a 30-06 if I couldn't account for the round visually or by sound.
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It's one of those "rules" everyone breaks...checking the bore. Only some the single shot shooters (the ones with an open breech) COULD do this for each round. NO bolt shooters seem willing to pull the bolt and tke a squint after each round, many lever gun shooters would need a 1/2 and a box of tools to do it, and semi-auto shooters never do.

And yet...whenever there is a buldged barrel, most owners who bring it into the gun shop or send it back to the factory claims they somehow had just looked down the barrel and it was clear.