I have a Springfield Armory Garand in the 1.9 million serial number range, which on one website indicated being built in 1944. I look at the barrel and see the markings '3-S-A-8-45".

Thoughts? Maybe made in 1945 instead?

With arsenal rebuilds, it’s not at all unusual for numbers/dates/manufacturers to not match.

I can’t say that SN range is an absolute, either though.

My Springfield Garand's SN dates to 1944, the barrel is dated 1955.

Following up...I went and got another Springfield Armory Garand, this time from the CMP. The serial number dates to about 1952, but the barrel is also marked 45. Maybe they restarted production for Korea and started by using barrels that were sitting in the warehouse from the end of WWII?

Ok; everyone step back.
A SA serial number of 1.9 mil was produced in September of 1943. No question about that.
Since all WW2 Cal 30 ammo was corrosive, barrels rusted out quickly, or were shot out, and were routinely replaced. So, a wartime receiver with a later barrel, is common.
Post war serial numbers were in the 4 to 5 million range.
We did produce M1s for Korea but the serial numbers started with 4.2 million. And in new production, they would not have used earlier dated barrels. Where would SA get them? They did not produce or keep inventory for no reason; all spares would have already been sold and delivered to the Army.
Depot rebuild and barrel replacement explains all mis matched barrels, and every other part on an M1. You can check all parts for period correctness; either by configuration, or part number. For example, there are at least 18 revisions for bolts alone.

This thread makes me think about all these “Correct” Garands that are being sold online. I’m not so sure that Correct Garands is a real thing as Tom states war time usage created a mismatch of parts on these rifles. My thinking is Correct grade Garands are all force matched by owners, not the government. You might be able to find an original condition Garand as issued, especially a post-war version.

No way to tell who made the parts match; but it wasn't the government; they sell them as is to the CMP; they did sometimes swap parts, but the ones they have now are pure crap; pitted receivers, etc.
And since none of the parts are serial numbered, it is impossible to tell if it was replaced with the right part number and or date; look at the finish. I've seen about 25 of them lately. Best ones have new barrels and stocks. I'm afraid the days of original ones are gone, except on the secondary market. All correct war time ones were always scarce.
One good example was posted for sale two weeks ago, here on AR. A NEW, Winchester contract, M1 barrel. So, I bought it. Turned out to be new for sure; newly phosphated, but what the pictures didn't show was that it had a throat worn to .303, and other evidence of having been on a rifle. In all fairness, the guy who posted it here was not the owner, and no one could tell a used barrel from a refinished. one. I should have known it was too good to be true, but I am weak. Point is, with M1s, you have to inspect them closely. And know what to look for. And not trust the internet.

Concur with dpcd. Finding a matched receiver and barrel is not that difficult. Getting the rest "correct" is much more difficult. I have a 1 million serial with a Jan '43 barrel that is largely correct. Interestingly, my brother in law has a 1945 era serial number receiver - with a Feb '43 barrel. Normally a nice, newer barrel would be screwed on. Super rough all around, likely a Philippine return (CMP).

Here is one I have; not matching, has a WW2 receiver and a 7.62mm barrel. But it is supposed to be that way!

Thanks dpcd.