Just got an A&K MK43 M60. It is completely stock. I run 9.6v NiMh in there now. But, I have several LiPo batteries laying around and wanted to use one in this gun. I asked my local airsoft store/tech and he said that all I would need to change is the spring. That statement didn't make any sense to me so I though I would look elsewhere. I searched the interwebs and came up with very few credible results. I have 7.4v and 11.1v lipo batteries. Can the 7.4v be used without upgrade? What about the 11.1? I am mainly looking to up ROF and I like how long lipo batteries last on the field. thanks for any help you give!