Just getting into M1 carbines and looking for a little info. Is there a site on the net that has info on serial numbers and when the gun was made? The gun I am looking at is an Inland with an IBM barrel with no date. The serial number is 2,975,XXX.

Also, is the flat bolt more desirable than the round bolt? This one has a round bolt.

Flat bolt is older, I dunno if that makes it more desireable to you.
I prefer the round bolt, as I have found it is better.
The round bolts were used on M2's and on M1s built during the same time period, as well as any M1s that needed bolt replacement after the round bolts became standard.
Make sense?
M1 carbines are found in multiple configurations.

What kind of a safety does it have?
Push button or switch?

What kind of rear sight does it have?
L Flip type or adjustable?

What type of barrel band does it have?
No bayo lug or bayonet lug?

Judging by the serial number you gave, your carbine was made in December 1943.

Quoted: Flat bolt is older, I dunno if that makes it more desireable to you. I prefer the round bolt, as I have found it is better. The round bolts were used on M2's and on M1s built during the same time period, as well as any M1s that needed bolt replacement after the round bolts became standard. Make sense? M1 carbines are found in multiple configurations. What kind of a safety does it have? Push button or switch? What kind of rear sight does it have? L Flip type or adjustable? What type of barrel band does it have? No bayo lug or bayonet lug? Judging by the serial number you gave, your carbine was made in December 1943.

It has a lever safety, an adjustable rear sight, and a bayonnet lug. Thanks for the info!

No prob!
All those signs point to a later M1 carbine, consistent with the serial number on the reciever.
I too have a 43 Inland with an IBM bbl.
Very nice little guns.

I strongly recoemmend picking up "the M1 carbine owner's guide" by Larry Ruth and Scott Duff.
You can get it from fulton armory for about $21.95, if memory serves correctly.
It is well worth the money.

Refer to internet site 'jouster.com'. A wealth of M1 carbine info is available. Charles.  

Dunno if this'll help or not.  I have an Inland Div.  M1A1.   BBL is by Underwood and dated 3/44.  

Serial range 5.218.XXX.   The piece is original and I/ve owned it for well over 35 years.  I'd guess yours is likely a year plus older.   Good luck.