I’ve seen some impact M3 rebuild kits on eBay or on various websites but I’m wondering what is the best rebuild kit for the gun. Looking for high-quality pieces and proper sizes. Thanks for the recommendations.
I believe that Oringsandmore offer 'kits' for many of the FX (maybe other brands) rifle line. You may need to call them as I don't see M3 listed, but I believe that they have them (?).
Once you have the kit, you can measure each O-Ring and order them for the future. With a standard minimum order of at least 25 of each size, you'll have enough to last you for a long time and they will likely be less money buying them that way.
There is a complete o-ring list for your rifle here on the forums, just need to search. I took that info to Oringsandmore and for $32 including shipping got a lifetime supply. Not a one time rebuild kit but like 10-20 of each needed.