I have a 22# spring on a steel guide rod and have not had any problems. This is the same as 527 is saying. No issues running heavy loads (my own, DT or BB). I have a .40 conversion barrel and I used to swap the stock spring in, but I do not bother any more. The 22# is fine for the entire spread of what I shoot.
As fr accuracy from the stock barrel; no load, heavy or light, is "inaccurate" through it on my copy. I get a little flatter trajectory with my KKM 6", but it is not more accurate.
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