I'll have to take exception to some of the comments in this one, specifically in re the WD-40. That's one product that I'll avoid for most firearm applications, especially in regards to the bolt. Problem is, it tends to gum up and forms a pretty tough varnish as it dries. Use a lube, such as a light oil, and use it in moderation. WD-40 is fine for applications where water needs to be displaced (which from what I understand, is what the "WD" actually stands for) but it's not a great lubricant. We need to use some common sense here, and match the prep work to what we'll be doing. If you're hunting in a wet climate, some oil that ill prevent rusting is probably in order, and a generous amount of it. If you're hunting in the arrid southwest, oil tends to attract and hold sand, grit, and all kinds of other crap you don't need associated with your bolt or firing pin. In that case, since rust isn't likely to be a problem, shoot it bone-dry, maybe with a bit of a dry graphite type lubricant. If you're shooting in an extremely cold climate, avoid any type of oil or grease that will stiffen up when you're in the field, as that'll reduce the firing pin's strike. In essence, there's not so much a "right" way to clean/lube the firing pin as there are a lot of "wrong" ways, depending on the circumstances you're shooting in. What's right in one, can be problematic in another. Match the technique to the situation, and you're ahead of thre curve.
That said, I'm still leaning towards headspace as being the cause of the misfires in this case.