Heavy Bullets and Cratered Primers

jephthai

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Jun 20, 2012
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I have been happily reloading my Savage 10 in 308 for about five months. Since Amax bullets disappeared from the market, I have scrounged what I could -- I found 200 Berger Hunting VLDs (190gr), and have been working up loads with these. I've only ever shot 155gr Amax before, so I was surprised to see that every load I try (VV N140 -- also the only powder I have available right now) gives me slightly cratered primers. Even moderate loads do this. Here's an example:

boVdRZF.jpg


I read every forum I could find, and I know that the CCI #200 primers I'm using are reputed to be soft, and to crater when looked at askance, etc. I have no other unusual signs (no sticky bolt, brass flow, loose pockets, etc.). I'm jumping 0.040" to the lands. The above selection are from my best group (about 0.7MOA), and I just want to see if I can get some input about whether I should proceed with these for my next match.

I don't have any other primers available (just about 2,500 CCI #200s!). I've seen pictures of much worse cratering, but it makes me nervous, and I can't find a load that doesn't do this with these Berger 190s.
 
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From your photo, I would say that your load is at/near max book load for your rifle. Not over-pressure, but right at max.

You didn't specify what your load was, but I personally would be very cautious about going any higher than you are.
 
From your photo, I would say that your load is at/near max book load for your rifle. Not over-pressure, but right at max.

You didn't specify what your load was, but I personally would be very cautious about going any higher than you are.

My intent is not to go any higher. I'm at 42.5 grains of N140.
 
Heck, my rifle makes primers look like that with any load I try no matter where I am within the min/max range. This is the only bolt rifle I own though so I'm not sure if this is common or not.
 
I had this issue when I started reloading. Took it to the local gunsmith/competition guru, his opinion was that it was just the primer flowing into the gap around the firing pin. Since your primers aren't flattened, it's probably the same issue I had.
 
I'm with sentry1 on this. I use Fed.210M in my rig and they look worse than yours. i understand you can order larger diameter firing pin that come closer to matching the hole. I havn't gone that route as I have shot thousands of rounds without blowing a single primer, so i just keep a check on it to make sure it doesn't get worse each time i change a load.
 
Shoot! My Rem 700 5R makes every primer look like that! I've been using CCI Bench Rest primers and 175 gr. SMK's behind 44.5 gr. of Varget with no issues for over a thousand rounds.
 
So does that mean I've just never approached full pressure with the 155 grain loads?

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I can't answer that, but I don't see any significant pressure signs on the ones pictured. Cratered primers are a poor indicator. Savages and Remingtons both do this, commonly.
 
I can't answer that, but I don't see any significant pressure signs on the ones pictured. Cratered primers are a poor indicator. Savages and Remingtons both do this, commonly.

Cool. Thanks for the help. I had run across the r700 idiosyncracy, but was not aware that Savages were known to do similarly. Thanks!

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...just got done playin with 200gr speers in a friend's '06. Using hybrid 100V I was getting pretty good craters 1.5gr below book max. My theory is that (in medium-capacity cases) they don't lend themselves well to shooting heavys with slow powders. However, that's only a thought, & someone will be along shortly to correct me.
 
My FN craters like that no matter the charge weight and bullet combo. I talked to the smith that built my rifle, and he said it happens with certain rifles. He also said Savage rifles do it a lot as well. I think the CCI's have a thinner wall on them also which attributes to this also. I use BR2's
 
Please explain this "cratering" you are talking about.
I see 2 things on the primers pictured.
1. the tool marks left on the bolt face from machining are coined into the primers and
2. the primers are extruding into the firing pin hole in the bolt face.

What would bother me more is if the primers were flattened, but the primers still have a decent radius around the edge.

Joe
 
Please explain this "cratering" you are talking about.

As far as I know, it's a crater if the edge of the firing pin impression rises above the surface of the rest of the primer. I can definitely feel the rim with my fingernail. I've looked at every picture I can find on the Internet of a cratered primer. I know that mine are very minimally cratered -- there are examples of much worse out there.

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Okay thanks for clearing that up.
In that case practically every case that's been fired out of my AAC-SD and my .260 Remington 700 have cratered primers.

What this indicates is excessive clearance between the firing pin and the bolt face, a common issue with Remington 700s, and, apparently, your Savage 10.

Unless I'm seeing ejector marks or flattened primers, I'm not even considering that I've got a pressure issue.

If it were me I'd have no reservation about shooting those loads.

Joe