I had 13 rounds fail to fire, out of 100 shot, because of primers in the 55gr Hornady Training rounds I bought recently from Ammunitiontogo.com.  The lot number was #3091957

I had similar issues with the 75gr Hornady Training rounds I bought from Scottsdale Gun Club, including the same failure to fire because of primers, and at least one popped primer.  The lot number was  #3090874

These rounds were brand new out of un-opened boxes, so no re-chambering.  And this rifle has had the following ammunition through it with zero malfunctions in the past;

PMC Bronze
Prvi, 62gr 223/M193/M855
Silver Bear 55gr/62gr
Hornady red box 55gr (no issues, will try to find the lot number)
Radway surplus
Federal M193 black box
BVAC 55gr reman
Wolf 62gr/75gr

And I'm sure a couple others I'm forgetting

Just bought a box of .38 +p Critical Defense and the first round was a DUD... After looking around wondering what to do and holding the weapon pointed down range for about a minute or so I fired the other 4 in the cylinder, S&W 642 airweight. Tried the DUD round in other chambers in the cylinder but no go. Will pull the bullet and see if its bad primer or what but not a squib load just the primer didn't go off. Again this wasn't .223 or 5.56 but .38 +p.. Will look at the box when I get home and post the lot #.

Here's the round
http://i253.photobucket.com/albums/hh76/preecherr/38criticaldefensejpg.jpg

Lot #
http://i253.photobucket.com/albums/hh76/preecherr/lotcritdef.jpg

Hornady 75 gr. BTHP MATCH  Lot # 3091197

...

More pics of the Dud round. Was trying to show the whole round in first pics. Hornady contacted me going to trade out ammo with me for a "GOOD" lot was their exact words. Sorry about the tore up place on the thumb was shooting my Taurus TCP and that dude is accurate but eats up the thumb.
http://i253.photobucket.com/albums/hh76/preecherr/IMG00243-20100221-1311.jpg
http://i253.photobucket.com/albums/hh76/preecherr/IMG00246-20100221-1312.jpg

Yea basically they're the same. I think the primers are hard. This individual round was tried so many times it has different primer strikes.

........

Saturday I took my brand new 6.8 upper out to shoot. Fired 5 rounds of Hornady 110gn Vmax, on the fifth round something very odd happened, It sounded like a normal round going off and the gun cycled I thought because when I pulled the trigger again it clicked, and the bolt was stuck closed.

At first I thought it was just a hot load or something like that, after I knocked the stuck case out of the rifle I found that the bullet was still in the case, That was odd because the primer was melted to my bolt.

Right now it looks like there isn't a flash hole in the case even though I am sure it went off more then just the primer, the case is bulged and was stuck in the chamber.

I really have no idea what happened.  Either way there was alot of smoke out of the wrong end.

I emailed Hornady but so far havent heard back from them.

Looks like the face/base of the primer separated from its wall and all the burning powder came out thru the pocket.

A bigger version of a pierced primer it seems.