I recently bought my first AK type rifle, a Romanian SAR-1 (as a Christmas present to myself)and today was the first time I fired it.  It's from Century Arms and I bought it new. It came with a 10 and 30 round magazine. When using the 10 round magazine it's fine and didn't jam once (I fired about 250 rounds through it).  However the 30 round magazine would jam after every 3-4 rounds.  Is there anything I can do to fix this?  Is there metal I should file down or something? Or is it just a bad mag and I should get a new one?  Any help would be appreciated.

edited to add: when jammed to bullet was still in the magazine.  It would not enter the chamber.  It looked like it might have been catching on something.

P.S. It was a hell of a lot of fun when it was firing, and pretty accurate too.  I think I've found a new favorite gun.

What? And I was under the impression AK's NEVER jammed..........

Buy or borrow another mag.  You know you need more than one.  If the replacement mag eliminates the feeding problem then repalce the mag parts with American.

Are you sure that your rifle is an SAR-1 and not a WASR rework?

it's not the mag it's the US part's in it
sale it and get a good preban
my ak has had 7000+ rds never a jam

Quoted: Are you sure that your rifle is an SAR-1 and not a WASR rework?

Actually, that was my first thought as well. It wouldn't be the first time a WASR conversion would have been sold as a "SAR-1".

Look on the left side of the receiver, does it say SAR? The WASR is a single stack mag gun, which Dremel Dude then widens the mag well, and may or may not try to do something about the feedlips. Based on your info so far, sounds like a poorly converted lo-cap to hi-cap gun.

I checked and it's an SAR-1.  It says:

SAR-1
Cal.7.62x39mm

The other side says:

Made by CM Romarm SA/Cugir
In Romania
Imported CAI Georgia,VT

Can anyone suggest any quality mags that I should pick up?

 Any EasternBloc magazine should work fine.
Romanian, Bulgarian, Hungarian etc.  And the Chinese.
 In the mean time, if you find yourself shooting, make sure that when you load the magazine all the rounds are seated so that they are against the rear of the magazine.
 

Quoted: use a small file or stone and lightly deburr the feed lips and front edges of the mag body.remove the mag's floor plate, spring and follower. stone the edges of the follower and clean the follower and inside of the mag body. lightly oil and reassemble. lightly stone the leading edges of the feed ramp that is riveted to the trunnion of the rifle (this is the small plate right in front, and just below, the chamber opening in the barrel).

What kind of dremel/drill stone do you suggest?

Well I would not feel so all alone,
Every gun must get stoned.
Ooops, wrong Bob...

Did you disassemble and clean before firing?
SAR's are notorious for being full of
grease and grit out of the box.

And yes try a new mag before doing any
filing or stoning.