I was shooting my still relatively new 2005 SEBR and I had about 3 FTF's.  I ejected the rounds and there was a small dimple in the primer instead of the normal deeper dimple.  Now, I was shooting PD ammo and I had a couple FTF's that were really just rounds missing primers.  I forgot to check the primers to see if they were maybe seated to deep in the casing and I didn't have a camara on hand to take pictures.  I have checked the bolt and carrier etc. and I see no obvious cracks or breaks.  So, from this information, can anyone tell me if it was the ammo or could something else have gone wrong?

Thanks

How could they be FTF (Failure to Feed) when they had a dimple on their primer?  A small dimple on the primer is a sure sign the round had been chambered.  The primer will be lightly struck by the firing pin when the round is chambered producing the characteristic light dimple.

I'm sorry, I had my nomenclature mixed up.  I meant 'failure to fire', I'm not sure what the acronym from that is.  That means that the round was chambered and the trigger pulled, but no bang.  Come to think of it, it could have been a case of the hammer not staying cocked back and following the bolt forward, but not providing enough force on the firing pin to set off the primer.  I'll look at the trigger when I get off of work today.

Thanks for the response though forest.

PD ammo isn't the best stuff out there. Try inserting ONE round in a mag, chamber the round, and fire it. Does the bolt lock back? Repeat this procedure 4 more times. Does it lock back each and every time? If not, you've got a short stroking problem.

EDIT: I misread and thought it was FTE.

Quoted: I'm sorry, I had my nomenclature mixed up.  I meant 'failure to fire',.

Ok Fail-to-Fire.

If the ammo was bad you'd have a full-size dimple (Primer strike), unless the tip of your firing pin was worn OR you had excessive build up of carbon around the firing pin hole in the bolt carrier (where the flange on the firing pin hits).  That is of course assuming you set the primers to the right depth.

If the disconnector failed and the hammer followed the bolt carrier down, then when you pulled the trigger nothing would have happened (hammer would already be down.  If the hammer fell when you pulled the trigger you'd know it - definate click sound and the feel of the trigger is different.

So did the rifle go 'click' when you pulled the trigger?

If it didn't either you had a disconnector failure or you forgot to take the rifle off 'safe'.

Quoted: Quoted: I'm sorry, I had my nomenclature mixed up.  I meant 'failure to fire',. Ok Fail-to-Fire. If the ammo was bad you'd have a full-size dimple (Primer strike), unless the tip of your firing pin was worn OR you had excessive build up of carbon around the firing pin hole in the bolt carrier (where the flange on the firing pin hits).  That is of course assuming you set the primers to the right depth. If the disconnector failed and the hammer followed the bolt carrier down, then when you pulled the trigger nothing would have happened (hammer would already be down.  If the hammer fell when you pulled the trigger you'd know it - definate click sound and the feel of the trigger is different. So did the rifle go 'click' when you pulled the trigger? If it didn't either you had a disconnector failure or you forgot to take the rifle off 'safe'.

Ok, all of these happened when someone else was firing my rifle, not myself.  I didn't get all the details of what happened exactly, they just said the pulled the trigger and nothing happened.  All I did was eject the round and it continued to fire fine after that.  

Anyways, when I get home, I'll look at the disconnector (now I know what that's called ).  I'm still learning the names of all the parts.

Quoted: Ok, all of these happened when someone else was firing my rifle, not myself.  I didn't get all the details of what happened exactly, they just said the pulled the trigger and nothing happened.  All I did was eject the round and it continued to fire fine after that.

Honestly it sounds like someone forgot to take the safety off.

Or here is an idea. You indicated some rounds were missing primers?  Check carefully with a bright light in your lower.  I've had primers pop out and fall into this area and it prevented the trigger from working.  A little jarring (say from racking the bolt carrier) and the primer could have dislogded and allowed the rifle to shoot again.  I'd check it over really carefully just to be sure.