Please see: United States Patent 8,695,260 CARTRIDGES AND MODIFICATIONS FOR M16/AR15 RIFLE

Am I reading this wrong? Has this person actually received a patent for specific cartridges? Did USPTO grant for nonspecific larger bolt & extension dimensions? What else does this cover?
How will this patent be interpreted?
How will it affect the industry?

It certainly looks like that, but it would be necessary to read the "patent file wrapper" documentation in detail to be certain.

From the claims and description alone it's hard to see what was considered to be novel and patentable.

It is easier to get a patent issued now.

The patent holder is left with defending the patent.

In years past I had any number of patents thrown out in court by showing publications from before the patent date.

That's what I was thinking. What's novel and not obvious about this? What's the "patent file wrapper" you mention?

The 'patent file wrapper' is the complete documentation of the history of the patent application all the way through to its grant.

For example, it will include correspondence (such as office actions and their responses) between the patent examiner and the applicant. Such documents likely include discussions of exactly what we're wondering, namely what is novel about these patent claims that is not obvious, and what limitations or boundaries on the scope of those claims must have been agreed to by the applicant in order to get the patent issued.

See http://info.legalzoom.com/patent-file-wrapper-20504.html for more info.

Here's a story from February I just ran across: http://www.thefirearmblog.com/blog/2016/02/26/kramer-defense-files-patent-bolt-heads-cartridges-larger-6-8mm-spc-wildcat-world-reacts/

With the exception of design patents, I've never seen claims that refer to the figures like that one.  Yes, I've seen reference numerals in claims, but this one is strange to me.

Interesting. That article appears to be discussing US Pat. No. 9,121,614

FYI: File wrappers can be downloaded here for free: USPTO.gov

I actually just received a call asking if I was available to challenge a patent.

I am retired but my PE is still active.

Not interested though.