Two cartidges I like to play with are the .257 Roberts and 7x57 Mauser. The Mauser round is still fairly easy to find and one can usually find some at big box store under the Federal Label. Sometimes they have Norma as well but I haven;t seer any Winchester or Remington lately on the shelves. Come to think of it, I haven't seen any Remington 7x57 ammo in some time, like in years. I did have a stroke of luck at a gun show when a fellow was selling bulk brass and I bought every round of Winchester and Remington brass he had.
The .257 Roberts, like the 7x57 is also a sometimes thing. Aboit 15 or so years ago I bought a Ruger #1B in .257 Roberts and 6 boxes of Norma ammo plus the dies to load them that came with the rifle. I used part of one box to see how that rifle shot and to check the scope that was on it. It was spot on and very very accurate. ff and on I do a search on Norma's site to see if they might be doing a run of .257 Roberts but no luck. I also have a Winchester M70 Featherweight in the .257R but it has not done well with any factory I've been able to find nor with any of the handloads I've made. I do have 6 rounds left from that initial box of Norma that I might try over the chronograph and for accuracy at the same time. Once I have the velocity from them maybe it will give me a leg up on getting some accuracy from that rifle. If not? I'll have to decide doing some work on the gun or just dump it on the market.
Paul B.