I phoned NEF and asked if the Ultra scope base would fit my SB2-2S3 stainless Handi Rifle. I was assured that it would but was mailed a standard Handi-Rifle base like that already on my rifle. I sent it back with a letter stating that I wanted an Ultra base if it would fit my Handi and to cancel my order if it wouldn't. NEF has canceled the charge on my credit card statement and has not mailed an Ultra base. I keep seeing posts that make me believe that the Ultra and the Handi bases mount on the same holes drilled above the chamber. Is this correct? Would like some real world info before I call NEF again.