Hi Mobuck
It seems the rifle differs from the original in that the H&R has a set screw that holds the latch in place on a round shaft. The original had a square shaft, square hole. During firing the screw can work loose allowing the latch to become loose which will cause the breech to blow open when the rifle is fired. So far I am finding out some people are/have drilling and pinning the latch to round shaft to "lock" everything in place. Or replacing some of the new model with original parts.
Thanks
Paul