In past I bought some 10 packs of 30:06 150grain ammo does anyone know anywhere it is still available

150 gr what ................?

It seems like Speer Nitrex ammunition was available in 5 and maybe 10 round "pocket packs". Nickel plated brass, I had some in 180 gr 5 round packs. It was good stuff, haven't seen any in years.

SGAmmo has some various 150g 30.06 in 20 round boxes. Nothing in a 10.

150 gr. ammo is pretty easy to get for .06. It just all comes in 20 round boxes unless you're buying in bulk, that's usually FMJ but soft point and even SSTs are available from Hornady and similar stuff from other manuf.

Speer Nitrex came in 4 boxes of 5 cartridges per 20 round box. I have never seen 10 round box of .30-06 ammo. Kynoch always sold everything in five round boxes.

The question I have is "Why?".

I remember that some years ago Browning was selling various rifle caliber cartridges under their brand name in 10 round clear plastic bubble-type packaging. I haven't seen any of that recently.

Years ago I bought some s&w 3006 ammo in 10 round plastic packs

Browning and S&W rifle ammo may have come from the same source. I don't think either loaded their own rifle ammo. There was a company called Amron which manufactured rifle ammunition for private-label sales years ago, and to a limited extent sold ammunition under their own name, and that could have been the source. I have a 20 round box of Amron .30-'06, which is fairly rare. Although Amron is "Norma" spelled backward, there is allegedly no relationship between them.

AFAIK 30-06 is currently available in 20 round boxes, not 10. It is available in almost any well stocked gun store or sporting goods store. You could always order online if the version you want is not available locally.