What commercial ammo is safe for M1 Garand if you do not use an adjustable gas plug?
Something in 150 gr using correct powder. Federal's American Eagle for M1 is expensive.
Would like something less expensive and not sure if I want to shoot Greek surplus.

Federal and Hornadys Garand specific ammo is expensive, thats your only choice besides a gas screw or surplus
Nothing wrong with Greek HXP, its good non corrosive surplus

Big +1 on the Greek HXP. Cheapest thing out there and works just fine for general shooting.

Why would you not want to shoot Greek surplus?

Just being careful with the M1 because it has a new barrel. How old is Greek surplus ammo?
I have shot Greek surplus 30-06 through a friend's M1 but did not get a close look at it.
CMP site has message about 5 - 15 % of HXP has case corrosion.

You won't find very much, if any, USGI surplus out there on the market at this time.  There is nothing wrong with the Greek surplus ammo.  It is non corrosive and accurate.  What they are talking about is surface corrosion, which might have been caused by moisture.  An added plus, is the Greek HXP brass is reloadable, and in some ways is easier to reload than USGI brass.  The primer crimp is much easier to deal with.
The only issue that may occur, is that in the early 70s, the extractor groove of the HXP 30-06 brass was redone to 308 style which is wider.  When that was done, They changed the matching part on the en blocs.  This does not cause any problems with HXP brass, but may cause problems with USGI brass.  These en blocs are marked JMO, so they are fairly easy to spot, and most have a heavy coat of parkerising.
I have shot quite a bit of of HXP ammo, and reloaded the brass with out problems.  The Greek HXP was actually better than the last batch of USGI stuff the CMP sold.  The USGI stuff sold quickly, apparently because it was USGI, but there were complaints it was underpowered and not as accurate as the HXP.

I have shot many thousands of rds of Greek surplus and never had a corroded rd yet

And this is dangerous to your new barrel how?

Load your own.

You will get more for your money

You will know what exactly you're shooting

Haven't heard a single case of someone receiving corrosive HXP when they order the 192 enblocs or 240 round items....

and THIS.  I don't touch my new HXP anymore... Working with 500 cases I've picked up at the range, assorted PMC, Federal, Springfield and my 4 bandos of HXP I've shot.  The rest is squirreled away in original packaging, straight from the CMP.

I just got 480 rounds of Greek HXP from the CMP.  1978 headstamp.  Awesome ammo.  Took less than 2 weeks to get it to me.

- AG

ETA:  This, of course, supplements my reloads

An easy mistake, but you misread it.  It's not that the ammo is corrosive but that some cases may be a little tarnished.

actually pretty much any of the generic FMJ ammo from winchester white box fed american eagle or rem-umc is fine. But as said above the best bet is cmp surplus. the hxp is NON CORROSIVE (this relates to the priming compound not surface irregularities on the case due to long term storage). For that matter go ahead and shoot old corrosive just clean the gun properly afterward. My club once got our allotment of  CMP ammo and it was all WWII era AP-corrosive- clean properly and you'll have no problems