I'd like to thank the other posters here for explaining why I suggested you use another minie with less powder. Another reason other than proper rifling engagement with the correct BHN lead for suggesting a smaller powder charge is because replicas like yours were often designed like the originals... with soft steel barrels only meant to shoot charges around 50-80 grains.

Since your powder volume average was 85 grains of hotter, more powerful 777, that is the equivalent of 100 grains of Pyrodex or Goex Black... way-way too much powder there. That's why I suggested around 55 grains... which is the 67-1/2 grain equivalent to Pyrodex/Goex Black..... much more correct for your Enfield. I'm sure a new rifle manual would of outlined that so I'm not blaming you for "possibly" overpowering it. I stipulate the word "possibly"... cuz' I'm not 100% sure how your manual for that gun actually reads.