You could take it to a lab and get it carbon dated.

What are the numbers on the back? Also, any badges showing a ship or anything else? If the numbers are SSN’s you might get someone in records that could identify the time frame that person served.

I’m not familiar with the jacket description, so I Googled it. Lo and behold, it’s similar to the jacket that I received in A.F. basic training in ‘71. In this picture, they call it a navy jacket at the top of the page, but in the description below the pictures, they say that the ‘jacket is the best deal an infantryman ever got’. What color is your jacket? See the white label in the neck area? It’s sewn onto a removable liner.

It just so happens that I still have my jacket. I keep it in my vehicle for emergencies, though these days, I doubt I could get it zipped up over my belly! My jacket still has the white label sewn into the jacket, about the same place as the label in the picture. Here’s what my label says; maybe you can do something with the info.
Stock No.: 8415–782-2939
COAT, COLD WEATHER, MAN’S, FIELD
DSA: 100–71-C-0181
JOHN OWNBEY COMPANY, INC.

If nothing else, I’m sure somebody on the net somewhere has a pictorial of the changes and improvements made to the jacket over the years, that you could compare yours to. They were ubiquitous for decades.

An antique? Seriously?! That makes me feel old; I’m going back to bed!

@wundayatta Let’s carbon date that ass of yours.

@Mama_Cakes That would be sort of pointless, since it is a currently living ass. Seems like a hostile suggestion, too. A jacket could be carbon dated much more specifically. You could possibly find out what year it was made, or at least narrow it down. Or are you not serious about it?

I think they were in use for several years for all branches of the military. I had a white one and an OD green one. My uncle still has his camo one that he got while serving with the Marines during the Vietnam war era between tours in country. He was a navy corpsman at the time.

There were so many issued over such a wide period of time that I don’t think you could get a specific age for a specific jacket. An expert could probably narrow down the age by looking at changes in the materials used and the cut of the jacket.

They are still made today for the civilian market.

A military supply store could probably tell you the era @Mama_Cakes. We have what we call “army and navy” stores here and you can go and buy old military coats and the like. I have a couple of WW2 coats and a naval pea jacket. I love them and they are very warm and cosy. Good buy!

Did some research and I got my answer. Thanks!

Do share @Mama_Cakes.

In case anyone comes across this, or if the OP is still looking for the answer, the year the contract was awarded is in the DSA number.
DSA: 100–71-C-0181 – The 71 indicates the year of contract. Manufacture, as near as I have been able to tell is usually the same or the next year