As with any old or new revolver you need to test the gun to make sure that it is not out of time and the cylinder lockup is solid, look for excessive cylinder gap, ect.
There are some good videos and articles out there about checking a revolver for all the issues they may have. Example: http://thefiringline.com/Misc/librar...ver-check.html
But since you only had splash back one time I would bet your revolver is fine.
If you are having excessive rounds failing to go off you may need a new hammer spring for the gun. You can get this from Numrich really cheap and replace it yourself. Requires removal of the grips and some needle-nose pliers. http://www.gunpartscorp.com/catalog/...aspx?catid=229
The H&R is not a terribly valuable gun so shoot it until it won't shoot anymore, Replace the defective parts and repeat.
When it is shot out - Never throw it away - sell it on gunbroker as a parts gun. There are people like me looking for parts guns every day.
Nothing is better than a Son/Daughter shooting with Dad. Some of my fondest memories no matter what the gun was.
The first gun I gunsmithed was an H&R. I was given the frame by my father and I purchased and fitted all the other parts from Numrich and she functions flawlessly. Ugly but works great and still own it today.
My H&R 733