Missing primer on a 6.5 CM

[Hunter26]

So I have a question on an issue I ran into this weekend. I was out with my daughter shooting our 6.5 CM in a Sig Cross. After a handful of shots I went to open the action and it was stuck. To the point I had to muscle it open. After I opened the action and looked at the case the primer was gone. I didn't see anything fall out when I opened the bolt but clearly it fell out somewhere. You can see the ejector mark from the picture. My question is what could have caused this and ultimately should I have any concerns moving forward?

I have reloaded for several years (not claiming to be an expert but not a newbie) and dealt with ejector marks, sticky bolts and primer signs when finding pressure. My first thought is somehow I double charged it or somehow got more powder than I should have. My only other thought is that somehow the bullet got pushed into the case but I don't think that happened. I feed the round into the rifle and am pretty sure it all looked/felt normal when it was put into the chamber. I don't remember noticing anything funny as far as sound or anything when the rifle went off. I am shooting suppressed.

I went back and weighted all my loaded rounds (about 35) and they varied from 360.1 gr to 358.6. I have always understood that each piece of brass can weight differently but was a little surprised to see that much of a difference. I would say that 80% of the cartridges were between 360.1 and 359.6 gr.

So what do you think...

 

[Chris in TN]

Impossible to say, but here's some options:

-Loose carry caused the projectile to be pushed further into the case, raising pressure a bit too far.
-Dirt or trash or tumbling media in the case changed effective case capacity
-extra thick piece of brass caused a reduction in effective capacity, raising pressure
-you misread the scale
-wrong bullet slipped through QC and you had a 147 in a box of 130s (or whatever)
-case had already seen excessive pressure on a previous firing and the pocket was already loose


It was *not* a double charge. You can't fit two charges of any rifle powder into a case unless it's *maybe* something like a reduced load of IMR4227. And if you double something like that, uh, you'll know it.

Take the rifle down and either find and remove the hiding primer or eliminate every possibility of it being there, or it'll hide until you need it the most, then jump out and jam your rifle. ARs are particularly bad about this. You'll shrug it off and keep shooting then start having 'gremlins'.

Worst part is, now you'll scrap that case and be left with 49 pieces of brass in a 50-round box and that's sort of its own form of punishment to some of us.

 

[Johnwell]

I had a buddy who had something similar happen to him—his brother had dumped the wrong powder back into a jug; I think it was imr3031 in 7828ssc.

In his case he cracked the bolt and had significant case head expansion. I’d probably pull some of those rounds and inspect what the powder looks like.

 

[NorthIdahoDude]

Worst part is, now you'll scrap that case and be left with 49 pieces of brass in a 50-round box and that's sort of its own form of punishment to some of us.

This... So much this...

 

[ResearchinStuff]

Was it rainy? Is all the case lube off your cases? How close to the lands are you?

 

[Hunter26]

Impossible to say, but here's some options:

-Loose carry caused the projectile to be pushed further into the case, raising pressure a bit too far.
-Dirt or trash or tumbling media in the case changed effective case capacity
-extra thick piece of brass caused a reduction in effective capacity, raising pressure
-you misread the scale
-wrong bullet slipped through QC and you had a 147 in a box of 130s (or whatever)
-case had already seen excessive pressure on a previous firing and the pocket was already loose


It was *not* a double charge. You can't fit two charges of any rifle powder into a case unless it's *maybe* something like a reduced load of IMR4227. And if you double something like that, uh, you'll know it.

Take the rifle down and either find and remove the hiding primer or eliminate every possibility of it being there, or it'll hide until you need it the most, then jump out and jam your rifle. ARs are particularly bad about this. You'll shrug it off and keep shooting then start having 'gremlins'.

Worst part is, now you'll scrap that case and be left with 49 pieces of brass in a 50-round box and that's sort of its own form of punishment to some of us.

If the worst part is a lost brass I am good but that yes that does suck!

 

[Hunter26]

Was it rainy? Is all the case lube off your cases? How close to the lands are you?

It started raining about 5 minutes later. I wipe off all my cases and I don't remember anything different with the cartridge so I don't think it had case lube on it. I would have to check my data on how far off the lands I am.

 

[Pickettpuncher]

The only time I’ve blew a primer I was way over pressure. It’s truly a wonder I didn’t end up hurt. Looked at my manual wrong for the powder and was way over max.

 

[Colorado Cowboy]

That my friend is because of excess pressure.....whatever the reason. There is lots of powder residue on the empty brass that you fired. Have you checked the fired pieces of brass for signs of pressure? If the primer is extruded around where the firing pin hit the primer, too much pressure. I would not shoot anymore of the reloads until you check the amount and type of powder you loaded (check several books/sources and check you bullets too. Did you clean your used brass?

Make sure you check all of the variables.

 

[Hunter26]

That my friend is because of excess pressure.....whatever the reason. There is lots of powder residue on the empty brass that you fired. Have you checked the fired pieces of brass for signs of pressure? If the primer is extruded around where the firing pin hit the primer, too much pressure. I would not shoot anymore of the reloads until you check the amount and type of powder you loaded (check several books/sources and check you bullets too. Did you clean your used brass?

Make sure you check all of the variables.

One of the things I failed to mention is I have fired probably 200/250 rounds of these reloads through this rifle and this brass would have been a least once fired but more thank likely 2/3 times. I can't remember for sure but I think I reloaded all 50 of this batch at a time and have about 25 left from the batch and never had an issue. I really don't think I could have used the wrong powder because I reload and put my powder back in the jugs right away. Plus if I had the wrong powder I think I would have had an issue before round #25.

I haven't seen any pressure signs on any of the fired brass.

Even though the weight of the loaded rounds varied more than I expected none of them were out of normal on the higher side. The majority of them were all within .7 gr and that included the heaviest round. Now that I am thinking of it I will probably weigh a bunch of spent brass to see the weight difference in them.

Best explanation I can think of at this point is that maybe I had some media stuck in the case.

 

[Colorado Cowboy]

When you cleaned your brass, was the spent primer still in the case? I normally clean my brass before I size and the primer is still in the case.