My H015-44 has about 600 rounds through it and there's been no problem with the hammer extension at all. I'm running the 31 lb. spring plus the small spring because leaving out the small one gave me occasional light strikes and a lazy hammer fall. I'm convinced the small spring gives the hammer an initial kick in the butt and reduces lock time but I never did try just using the 38 lb. Waiting to see if it works for anyone else before I pull the stock off yet again.
One thing that surprises me is that I'm getting used to the 5 lb. trigger pull and enjoy ringing the swinger when shooting offhand with the .44. I found a lighter plinking load with the 225 gr. RCBS GC that shoots to the same POI as the heavier hunting loads.