Not mine, but here is a pic I found that shows one persons solution with a sight mounted on the barrel of an AR where the sight has a bayonet lug. They do, or did at one time, make just bayonet lugs that clamp on the barrel and you could try one of those then space it properly for the bayonet ring to fit properly on the flash supressor.
I don't think thats the S&W SW3B M9 bayonet, but its a reasonable copy to get an idea of what it would look like mounted with a lug on the barrel.
DPMS used to sell a clamp on lug that would work fine if you don't mind clamping something on the barrel, but they discontinued them. There is someone out there who sells one that would work, I come across something every once and a great while when searching for something else but finding it is like looking for a needle in a haystack.
However, I did find a clamp on lug for the standard weight barrel, $24.95 and says its in stock, here >
AR-15 Bayonet Lug Adapter, Standard Barrel < I think this will work on the Sport barrel too but you will need to check it out to make sure. I can't vouch for the quality and suitability of that clamp on because i've never used it, so you will need to decide for yourself.
You may be able to find a clamp on lug at a gun show too, there is always a private person someone with a table set up selling something at a gun show that has a few of those hard-to-find items or those things no one else buys much of. Also check out the local gun shops, and pawn shops that sell guns too. Just for giggles I went to my LGS yesterday, its about a mile from where I live, because I knew they carried the S&W SW3B M9 bayonet and I wanted to take a look at it up close. They would throw in a clamp on lug with the S&W SW3B M9 if you bought one, of course their prices were a little higher than what you can find on line. They did not have a Sport in stock or I would have taken a look at that too for you in combination with the S&W SW3B M9. You could also find another clamp on thing (like a sight), maybe a used but in good shape thing, that you can modify by removing the sight or whatever else is on there, just leaving the clamp on lug as long as you don't need to compromise the integrity of the clamp portion. I've seen a few sales on bipods that included a clamp on lug too, and there is a chance in a LGS or at a gun show or even on line that you can get a clamp on lug from their "gun smith" person or services if they offer to mount things for people who purchase weapons when they may not directly advertise a clamp on mount for sale. You may be able to find a private individual on line that is selling some of their stuff to get some extra cash and one of their items may be a clamp on lug that will work.
If you use the clamp on bayonet lug you do not need the adapter because then you move the clamp on further up to account for the 16 inch barrel length so the bayonet ring is in its proper postion on the flash supressor (if you have a flash supressor - if you don't then you are out of luck)
Personally, I would not clamp a seperate lug on my barrel and would go for the tacticool solution first if I really wanted to mount a bayonet and could live with the thing not in the technically correct position and can live with the shortened blade projection. Of course i'm more into the practical real world use rather than the cool factor look.
Taking into account the S&W SW3B M9 bayonet dimensions - If you have a 16 inch barrel and a carbine handguard; The overall length of the bayonet is 12.75 inches, the blade is 6.5 inches, this means a handle length of 6.22 inches. Taking into account the measurement from the bayonet lug on the Sport at the front sight to the end of the flash supressor (if you have one) its approximately around 7 to 8 inches (not exactly sure for the Sport), this leaves a blade length beyond the end of the barrel of maybe 3 to 4 inches.
The last real U.S. military bayonet charge was in Korea, but I believe there was some U.S. military bayonet use in Iraq. Not sure of the exact details but a squad of British soldiers did a short bayonet charge in southern Iraq, killed 3 to 1 and took prisoners too and the rest of the Iraqi forces ran off. I do know though that the British military even today will bayonet the bad guys butt in a heart beat.
The bayonet lug started out life on an old German Masuer. It was either WWI or WWII vintage....been too long to remember. 
