Original 50/110 rifles had a slow twist and, judging by the short ogive bullets, typical of factory rounds back in the day, the factory did not optimise the chamber and feeding for longer bullets. This is understandable given that original rifles fired light for calibre bullets at relatively high speeds. However you can get WFN bullets loaded to 2.8” LOA that feed and cycle in a levergun, if the smith knows what he’s doing.
For starters I’d suggest you use a barrel twist that will stabilise heavier bullets. The norm these days for 50/110 conversions is around 500gr. A 1 in 20-24” twist will work with a wide range of bulllets, including the lighter ones. A 50/110 has substantial powder capacity and full power loads in a strong rifle will be in 458 Win Mag territory, ie stout recoil.
The other area to pay attention to is the method of retaining the magazine to the barrel. This is particularly important if you use heavy loads.
There are jacketed bullets suited to levergun use made by Barnes and Woodleigh. When you choose your smith I would suggest you supply him with a few dummy rounds to make sure the conversion feeds and cycles bullets you intend to use.
Plan your conversion carefully and work out what weight you want to end up at. If you’re going to hunt with it, you really don’t want a 10-11lb rifle that is muzzle heavy.
