Out of the box the 338 Ultra Dog had a very tight chamber and wouldn't chamber the 250 Gr. Remington factory ammunition, the extractor wouldn't catch the case rim to extract the cartridge and I don't know if the ejector would have worked or not.
I contacted Remington and they were very helpful and pleasent. I sent the gun to them as requested, a week or two later I got a call from one of the contractors who does thier warranty service work, he said the gun had been received, would be repaired and shipped the next day. About three weeks later I called to see if there was a problem as I hadn't received the gun they (contractor) had no record of me or the gun, he said he would find out what the problem was and get back to me. Sure enough he called me the next morning and said he had found the gun and would ship it by air. Great, I got the gun, it had around 6000 miles on it, probably handled by numerous people, however it had not been touched by a Smith. At this point I made contact with Remington again, once again they were pleasent and really didn't know what to say. They asked me to ship the gun back at which point I declined and stated I would deal with the gun. I wasn't mad as this wasn't a big deal, it was somewhat comical looking back. I took the gun to Wild West Guns and had them do the work, turned out they are an authorized service center for Remington (NO, I don't know why Remington had me ship the gun to New York.)
Yes, it worked reliably and the guys who shoot Remingtons thought it was great and worked fine, however I wasn't comfortable with it and never would have trusted it in the Bush.
I must admit I was very impressed with the 338 Ultra Mag as a cartridge, it is very flat, very fast and very strong.
It also kicked like a mule.