I suspect it was around the time of the Cobalt Bomb, which may not have been the last Brunswick ball. (The Uraniums, Golden Nugget, Bulletand Bombs were all Brunswick/Bayer covers.

The Gforce balls were the first set to use 900G/Old Columbia covers.

Ok. Was hoping to try some of the older ones with the Brunswick covers

I've owned many of the older Brunswick-poured Lane #1 pieces and they are every bit as good as the Brunswick pieces of the same era, especially those with the C2 core in it (Blueberry, Pink Raspberry, Black Raspberry Pearl Cherry, and Emerald).  The Lane #1 diehards pay premium prices for these, even pieces with multiple drills.  So be prepared.

I would rank the Blueberry/C2 with it's PK18 cover as one of the best balls I've ever owned.  The Viper Pearl, with a reactive Rhino Pro cover (not sure which one) was also one of the hardest hitting balls I've thrown and a great piece.  Reminded me a lot of my Gold Rhino Pro.  The Bullet was a dry lane gem.  And the Gold Nugget was a unique piece given the PK17 particle shell.  I sold mine but just got a single drill one off Craigslist for $10.

Many people swear by the Cherry Bomb and Black Cherry Bomb, but I never matched up with the Bomb core. 

Anyway, many great balls to choose from, as long as you are willing to pay.  I sold all of mine off except for the Retro Buzzsaw THS, which has Superflex (Columbia 300) and ranks just barely behind my Versa Max as the best ball I've ever owned.

And yes Jeff is correct Brunswick poured everything up until the G-Force was introduced in 2007.

The G-force era is where I have seen the most older ones available.  Which is why I was hoping they were still Big B.

IMO it is no coincidence that they were the first non - Brunswick balls and the ones most readily available.

I was looking for this ball on the Lane#1 website listing of their retired balls - Uranium HRG. It was not in their listing. I found here:
http://www.ballreviews.com/lane-1/uranium-hrg-t775.0.html
http://www.123bowl.com/ball.cfm?ballid=3061

I tried it and it was probably the Lane#1 ball that I had the least success with. Even though it had the Uranium name (all the rest were made by Brunswick), I think it was the first or one of the first made by 900Gobal.

I thought they were still 900/AMF

The Lane # Uranium (solid and pearl) were the last Brunswick covers on a Lane #1 ball.  Oddly enough, the Uranium HRG was a Columbia poured cover, and the first non-Brunswick cover on a Lane #1 ball, to the best of my knowledge.

I believe 900 Global took over the covers with the G-Force line.