I have been using 3f in my .50 cal. Hawkins 1 in 48 inch twist barrel for 20 years and have had no problems safety wise. Be sure to reduce your load by 10 percent when switching to 3f. 100 grains 2f = 90 grains 3f. THERE IS NOTHING I HAVE READ THAT SAYS THIS IS A SAFE PRACTICE. The only reason I have been told for doing this is to reduce fouling. So if you decide to switch, do it at your own risk.