Thank you, Bruce in Oz, for pointing out that little-known feature of Metford rifling.

If a Metford barrel does get worn (and they did, which is why they were replaced in Service), they often can be persuaded to shot with reasonable accuracy by using a long, heavy roundnosed or blunt-nosed cast bullet with the longest bearing surface you can manage. This will be strictly a handloading proposition, but it can be done. If you try this, try also using a very quick powder (3031 is a good example, or RL-7): gives the bullet a good kick on the gas-check and helps it to obturate to fill the bore nd to provide good rotation. You also can size your bullet larger, given that your mould casts them oversize, as do most iron moulds. Lee Liquid Alox has worked very well for some old rifles with Metford barrels.

By the way, a LOT of these were converted to Enfield barrels when the original Metford barrels wore out. If your carbine has a big letter "E" on the Knox-form (the flat on top of the chamber), then the original Metford barrel has been changed-out for an Enfield-rifled barrel.

Hope you have some nice pics you can post for us. We need nice things to drool over!

Good luck and have fun!