Information about M1 barrel markings

[ChrisK]

I have an M1 that I have had for a couple years. On the barrel it is maked SA 6535448 6 66 BU29. Could anyone give me some history on this barrel?

[AtlLaw]

Been a long time since I was on my Garand kick so I've forgotten a lot but the barrel is pretty easy.  It should be a Springfield Armory barrel made in June 1966.
 
Most all Garands were rebuilt (at least once!) at one or another but it seems to me there was a major rebuild about that time.  Probably because of the thousands being sent to different parts of the world.
 
But now that I think on it I don't remember Springfield making new M1 barrels in that time frame.      I dunno.      Duffy or my ol' friend Walt Kuleck (sp) could tell ya every thing you wanted to know right off...

[mauser98us]

SA stands for springfield armory. The other number is the drawing number for the print.

[AtlLaw]

I have an M1 that I have had for a couple years. On the barrel it is maked SA 6535448 6 66 BU29. Could anyone give me some history on this barrel?

Hey Chris, do me a favor and check the rate of twist on that barrel.  That date has got me curious but not enough so that I want to get into a lot of researching.   
 
FYI, and as I said, the manufacturer was Springfield Armory. The "6535448" is the drawing number, the 6 66 is the date of manufacture and the BU29 is the heat lot code.  Although as I remember that heat lot sounds about right for around 1966, I just don't remember SA making any standard M1 barrels at that time.   
 
My curiosity will be satisfied if you tell me what the rate of twist is.   

[ChrisK]

I am guessing 1:10 with 4 groove rifling.

[AtlLaw]

Well, I would also guess so if it were a standard barrel made through..  what? 1956?      I'm curious to know if it is a 1 in 12.   

[ChrisK]

It shoot very good. I know that the muzzle wear and throat are out there. The empties almost look like .35 whelen's haha. But this rifle still fires very accurately. I knew that it was  made in June of 66' but I didn't know about the heat cycle. I saw that and didn't know if it was a dutch or korean return or heck even a vietnam return. Like I said though, it is a pretty good shooter. Thanks for the help. PS, I thought only the .308's had the 1 to 12 rifling?

[AtlLaw]

I thought only the .308's had the 1 to 12 rifling?

As far as I know that is correct.  But you never know.