I'd be interested as well having one regulated but the only regulator I've seen installed was the Altaros which didn't even incorporate a plenum spacer. Velocities really dropped off. The installation was a no drill and pretty slick though. Jimmy
I would go with Robert Lane as he has the best service and support of all the regulator manufactures I have worked with. if you ask he will dend you detailed instructions on the ideal hammer weight and valve spring tension allong with parts to adjust them.
Huma or Audrius would be my top choices
I know this is an old thread, but instead of starting another thread I would to ask if any members have put a regulator in a .25 cal Huntsman Regal XL and have some before and after data of the modification.Thank youM