Garand Firing Problems

[Sunray]

"AMA 91" is 1960's vintage Danish milsurp. Supposedly uses a 148 grain FMJ, non-corrosive Berdan primer at 2,910 FPS(if you can believe the advertising. One place says 148 grains. Another 149.) The CMP sold the stuff before 2009. However, you have no idea how it's been stored since then.
It'd be a good idea to try some different ammo out of your M1. That'll tell you if the rifle or the ammo is the issue. Far more likely to be the ammo than the rifle. Head space issues have other symptoms than just blown primers. There any extraction issues?
Hornady loads 168 grain ELD Match ammo specifically for the M1 Rifle. $33.99 per 20 at Midway.
Oh and download the assorted, free, .pdf manuals. Note the need for the provided UN and PW.
Biggerhammer.net - Miscellaneous Firearms Technical and Training Manuals

[Ex Crab]

I recently bought 500 rds of AMA ammo with a 61 date stamp. It shoots fine out of my post WWII Garand. The ammo is being sold all over the country and I have heard no reports of problems with it. The ammo is allegedly M2 and was manufactured in Denmark for their M1 Garands, so the ammo was made shortly before the Danish Army got their new rifle in 7.62 Nato, which means it's been languishing in some depot for decades, but doesn't look old.

[Col.Colt]

The gun was extracting the fired casings just fine but the bolt would lock back into battery without chambering a new round. I had manually slide the bolt back to
to pick up a fresh round.

[Sunray]

"...but the bolt would..." Covered in the .pdf manuals. Under failure to feed, I think. That's not ammo or gas related though. Clip latch or follower, I think. This internet at the library is no good. Have 5 minutes left.
Hatcher's Book of the Garand has a trouble shooting chapter. Same as the .pdf.

[Col.Colt]

I am traveling for the next few weeks but plan to diassemble the gun and give it a good cleaning and inspection when I return.