I'm considering getting a 300 Ultra mag and was wondering if you can only get them through Remington or does Sako.Winchester. or any other companies offer them thanks for your help

I think most major manufacturers chamber the 300 RUM. I know that Savage does in their 116FSAK, with the accutrigger. This should be a sweet shooting rifle! This is the weather warrior series and has a synthetic stock and is SS.

Yep, Sako has em. You can find them for less than 500 dollars on some online auctions in winchester.