I don' t know if Browning ever chambered its BLR for the .257 Roberts. But you could have one of Browning' s " long action" lever guns rechambered for the .257 Roberts. (It would not fit in the short action BLR' s which are limited to case length cartridges of .308 Winchester length...ie.51mm in length.) Of course the Roberts originated with the 7X57 and would not fit the shorter action lever gun. Browning chambers the lever in a " long action" which handles .270 Winchester, .30-06, etc. One of these could be rechambered by a competent gunsmith to .257 Roberts without very much difficulty, (though it very well may not be cheap!).

I don' t know how determined to have a lever in .257 Roberts you are....but you should be able to find a Savage 99 in nice conditon chambered for .250/3000 (.250 Savage) for a very reasonable price. I' ve owned a .250 and it was a very capable quarter bore. It would be a way to have a quarter bore for much less than a conversion!

Let us know what you decide...and good luck!

P.S. You could mount nearly any scope you wanted on either the Browning BLR or the Savage 99. Though I would personally probably look at something like a compact fixed 4, a compact 2X7, or maybe as much as a compact 3X9. I have personally owned and used several Burris Compact 2X7' s and found them very nice scopes indeed! Either of the compact variables would work great on a lever quarter bore! On the other extreme when we scoped my wife' s Savage 99-358 (chambered of course for the .358 Winchester) we went with a Weaver 1X3 variable and never felt underscoped.