Of course my S&W M&P (and my other S&W's as well) was/were made in the USA. My Glocks were made in Smyrna, Georgia USA, but of course the parent company is in Austria. The lines of origin can be different shades of gray--as the standard sidearm for the US Army (and used by a lot of US police forces) is a Beretta 92, made in the USA, but Beretta, the oldest gun maker on earth, has a USA head quarters, but is an Italian company essentially. S&W is making inroads into these markets--recently the Los Angeles police moved to the S&W M&P. I am sure Glock's watching intently. Beretta's US Army contract will be running out and the decision making process on the new standard gun/s should be interesting.
For a long time now, the Honda Accord and Toyota Camry have been built in the USA, but of course the parent companies are in Japan. Even what we see as American mainstays, like the Ford F150 pick up truck, a lot of other USA brand vehicles, including Harley Davidson Motorcycles and many more products, have a significant number/percentage of parts made overseas.
The US Govt's 'guidelines' as to determining if a product can claim 'Made in the USA' cover 40 some pages.
Anybody remember when you went into a Wal-Mart and there were signs all over saying 'We sell 'Made in the USA products'? I think if Sam Walton were alive today, he'd be rather upset. Even US Flags are typically made in China today. The US Army's elite, first strike Rangers almost had a rebellion when their hard earned berets were briefly outsourced to Chinese manufacture.
S&W is the USA distributer for Walther (backs them with a paltry one year warranty too) and Walther is sort of hard to pin down as to where there guns are 'realy made' versus were they are finally test fired and stamped as their final assembly point.
To compound complications, companies may put individual parts out to bid and a parts origin and the percentage from any given country can vary from time to time. If one country's currency is particularly attractive against the dollar, we may outsource from there for that time period.
Chances are that many parts of the computer you're using right now will vary in origin from week to week, as they 'job shop' for the cheapest hard drives, DVD player/burners and many other components.
Sadly, gun manufacturers today are little different in this global oriented economy.