Mt Thomas Bland and Sons 20 was nitro proofed in 1899 for 7/8oz loads.
I also used to own a greener that was sent back to Birmingham to be re-proofed for nitro.
Both are Danascus barreled guns.
Mostly I shoot BP out of my Damascus guns, but do have some low pressure loads I use as well on the skeet field.
For hunting I use BP however.
DT

Of course I have shot all my vintage guns - what do you think they are called SHOT guns for??!!