I looked over couple quite recently. One was W.J. Jeffrey BLNE Wildfowl gun (heavy by English standards 1&1/4oz proof) brought in by Briley of Texas the other was common Webley & Scott BLE gun. Both had original 2&3/4" chambers. I would think 2&3/4" chambers would be quite common on post WWII guns like the Webley 7xx series.
Those with original 2&3/4 inch chambers will be preferred by shooters and therefore held on to and bought up more quickly. It's nice to be able to buy 1&1/8 oz hunting loads at local Walmart instead of having to spend extra money and trouble to track down ammo with 65mm or 67mm case length after firing. This will seem to make them more rare on our marker and rightfully so.
