I sold and Army Navy 450/400 3 1/4 to Ray and he used it in Africa last Fall.

They are quality rifles built by a few of the Birmingham and London makers. Could be anybody. What is it a Boxlock or a Sidelock?

The cartridges are easily handloaded with a good selection of bullets. Brass is available from BeLL.

Value will vary. I would guess that for a Boxlock, if the rifle is in top nick mechanically, it would start at $6500 and go up to about $10,000-11,000 depending on appearance. Rough guess without more info.

What specifically do you want to know?

I have a Alex Henry in that caliber and love it. I have only had it about 6 months but it is quickly becoming a favorite because of the quality and the caliber. Low recoil and a heavy punch.