Two primers didn't go boom

Sasquatch

Sasquatch

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I was loading up my first set of 308 winchester, using S&B large rifle. I only loaded up 20 or so but I had primer failure on two of them. They were evenly seated, and very well dimpled (I tried in both my bolt and my AR10) but neither went boom.

(The good news is that my first 308 handloads that did go boom had great groupings)

I've had very good luck with S&B small rifle (in that I've never had a primer failure) after many hundreds loaded. Is this a bad batch, or are large primers more finicky- do you have to seat them deeper or something?

Pictures coming
 
Pull the bullets, dump the powder and push them out and see what the other side looks like. Maybe they were made on Monday morning or Friday evening. "Insert usual safety notification."
 
I had a Winchester rifle primer do that recently. I pulled the load, punched out the primer, and there was no primer compound in the cup. The inside of the cup was shiny.
 
I ran into an issue with surplus powder awhile back. Two different canisters purchased at nearly the same time, went through the first 8lbs without issue. Then the second bottle gave me problems. "Click" is all I got on about 1 in 25. I determined the primer was firing (didn't hear it) but wasn't hot enough to completely ignite the powder. Switched to magnum primers (as the loading book called for but I didn't pay attention). Problem solved.

When I pulled down the defective loads there would be a small clump of partially burned powder from the bottom of the shell.
 
Last edited:
muskrat said:
I ran into an issue with surplus powder awhile back. Two different canisters purchased at nearly the same time, went through the first 8lbs without issue. Then the second bottle gave me problems. "Click" is all I got on about 1 in 25. I determined the primer was firing (didn't hear it) but wasn't hot enough to completely ignite the powder. Switched to magnum primers (as the loading book called for but I didn't pay attention). Problem solved.

When I pulled down the defective loads there would be a small clump of partially burned powder from the bottom of the shell.
Click to expand...

Those could have been a couple of the rarely seen in nature "hang fires" with a little luck.
 
Thanks for the report. Have been using S&B primers mostly in small rifle and pistol apps for a couple years now and have not had any issues as such. Will be a bit more wary now.
 
Bailey Boat said:
Look at the second one from the left and compare that to the last one on the right.....
Click to expand...

I won't call that flatten, just lighting. You can still make our the crater around the firing pin indention. Flatten would have flatted that. Also the edges are still beveled and not flat. Pull the bullets, check the powder for clumping and then deprime the cases looking at the primers. Never used S&B primers for reloading but shot thousands of their ammo while in Germany without issues. What primers did the load manual call for?

CD
 
Combat Diver said:
I won't call that flatten, just lighting. You can still make our the crater around the firing pin indention. Flatten would have flatted that.
Click to expand...

A flattened primer can't flatten the firing pin crater. It craters because of the clearance around the firing pin that allows the material to flow back into that clearance space. And if the primer was flattened all the way to the edge it would have most likely been catastrophic. Regardless, he is at the upper end of a potential over load....
 
Bailey Boat said:
A flattened primer can't flatten the firing pin crater. It craters because of the clearance around the firing pin that allows the material to flow back into that clearance space. And if the primer was flattened all the way to the edge it would have most likely been catastrophic. Regardless, he is at the upper end of a potential over load....
Click to expand...

This may be a prime example of a soft primer. Note just how deeply the two duds are dented. The load may well be in the safe range in terms of pressure, but maybe not for this brand of primers. The "crater" shown in the pic could also be the result of a slightly over large firing pin hole and again, be perfectly safe.

Note to all you guys who reload- substituting primers can lead to pressure issues!!! A load that is completely safe with one primer may not be with another. Be careful!
 
The truly flattened primers I have seen were flattened all the way to the edge of the hole with no beveling. Almost all my 41 Magnum factory loads and many of my 357 Magnum factory loads show primers flattened so that they fill up the bevel. A friend gave me some Hornady Light Magnum 308 rounds because they did not work too well in his Browning Lever Action, and all of the cases he had fired had the primer flattened so the bevel did not exist. The primers looked like little flat-top mushrooms when I removed them. The bevel still exists on the cases pictured, so I would not be concerned with excessive pressure.

The cratering, as stated, would not flatten out with excessive pressure because it is from brass from the primer being forced up into the firing pin hole. I have seen cratering with loads that were not excessively hot.
 
Thanks for the comments- I haven't had a chance to pull them yet but will. Doing some reading it looks like I really need to set them deep(er) to make sure they anvil has something with which to stop its motion.

As far as cratered primers, yes, I saw the puckers, but not flattening. I'll try some more loads, but I'm thinking this is either really soft primer cups, or a characteristic of the rifle (Thompson Center).
 
A side note on the OP, mixing military and commercial brass can cause big pressure variations and the problems that arise from it's usage.
 
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