The conversion is sold by Precision Rifle out of Manitoba. www.prbullet.com
(I am in no way affiliated with them). They sell it for the Omega, Encore, Apex, and several others I believe (not Knight guns).
While I have yet to fire mine, there are supposed to be several advantages over 209s. First, think why they started using 209s...because they were a convenient self-contained primer that could be removed by hand, NOT because they were tested and found to be the best ignition method. A 209 is much more powerful than rifle primers because a shotgun shell works differently...the pressure must build before the shot breaks through the crimp, since there is little resistance in a shotgun barrel. Hence a very powerful primer to burn the charge quickly.
If you push a saboted bullet down the barrel of an Omega (NO powder) and fire a 209, the bullet/sabot will fly 20 feet out the barrel...I've seen this personally. In a rifle/ML, there is no need for this kind of power. With 777 powder in a ML, many people experience the infamous "crud ring" that forms around where the sabot was seated and must be worked out of the barrel upon every firing. My Omega has a really bad one that sometimes sticks the cleaning rod fast in the barrel.
The theory put forth for the conversion is that sometimes a 209 will start the bullet down the barrel before the powder fully ignites, causing unexplained fliers and larger groups. Seems logical to me.
While I have yet to personally test the system, I have heard reports from others that it #1) increases accuracy and #2) eliminates that nasty crud ring. I'm guessing the crud ring is gone because the powder burns more uniformly rather than baking onto the barrel before it can ignite properly.
I'll be shooting it on Sunday if it doesn't rain, so I can give you my personal opinion on it then.