Flattened Primers?


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ConcernedCitizen
September 26, 2011, 10:44 PM
I'm having some trouble reading the primers on my .308 loads, and would like to get a few second opinions.

In your opinion, do these primers look flattened to you, or show signs of cratering?

http://farm7.static.flickr.com/6160/6187122623_31bfbce374.jpg (http://www.flickr.com/photos/67211025@N08/6187122623/)

If you look at the middle row of cartridges, the two on the outside edges look nice and round, but show signs of what might be considered cratering. The primers in the middle of the middle row look flattened, but they almost look like they were smashed against the bolt face, rather than flattened due to high pressure.

I'm using 43.0 grains of IMR 4064 behind a 165 gr. Hornady BTSP. The primers are CCI 200, and the brass is new Winchester brass. These were fired out of a Mossberg 800A, and were worked up from 41.0 grains. The primers look similar across all loads, not just the higher end. Blue is 41.0 grains, and red is 43.0 grains.

http://farm7.static.flickr.com/6157/6187675894_814b28841d.jpg (http://www.flickr.com/photos/67211025@N08/6187675894/)
http://farm7.static.flickr.com/6155/6187675900_89837a2c0d.jpg (http://www.flickr.com/photos/67211025@N08/6187675900/)

It's a mid-range load according to Speer #13, and there are no signs of sticky bolt lift or extraction. There are some definite machining marks visible on the brass after it's been fired, though.

http://farm7.static.flickr.com/6169/6187675902_529bf578d7.jpg (http://www.flickr.com/photos/67211025@N08/6187675902/)

My rifle really likes these loads, and I'm fairly certain that I'm still within safe territory, but I can't get over the fact that some of the primers look so flattened. I'm pretty sure that it's just the primer being flattened against the bolt face, but would really like to get some expert opinions on the matter.

Is anyone willing to help assuage my fears, or perhaps save my life if I'm sorely mistaken?

Thanks in advance!

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gordy
September 26, 2011, 10:53 PM
I have been reloading for 35 years and they look flat to me.
You could back off just a bit on the charge and see if there is a change.
Good luck.

gordy
September 26, 2011, 10:55 PM
you might try a different primmer that may help.

ConcernedCitizen
September 26, 2011, 11:07 PM
I have been reloading for 35 years and they look flat to me.
You could back off just a bit on the charge and see if there is a change.
Good luck.
The problem is that I'm seeing the same issue all the way from the starting load of 41.0 grains. I've thought about switching primers, but from what I've read, most large rifle primers have the same cup thickness. I do have some Remington primers I might try next, just for fun.

Frozen North
September 26, 2011, 11:09 PM
I had a .270 that showed similar signs of pressure with loads that should have been well within the realm of safety. I too questioned the signs because they should not have been there. Back off the powder of try a different bullet. My rifle plainly did not like the 150gr Hornady bullets I was feeding it.

Edit: Are you getting your primers seated deep enough?

tly999
September 26, 2011, 11:20 PM
I would suggest you check the rifle's headspace, just to make sure that is not the problem.

ConcernedCitizen
September 26, 2011, 11:23 PM
I had a .270 that showed similar signs of pressure with loads that should have been well within the realm of safety. I too questioned the signs because they should not have been there. Back off the powder of try a different bullet. My rifle plainly did not like the 150gr Hornady bullets I was feeding it.

Edit: Are you getting your primers seated deep enough?
Primers are below flush, and brass is new. This rifle only seems to like the 165 grain bullets, as 150 grain bullets wouldn't group at all, especially factory ammo.

I looked at some of the factory brass I had from this rifle, and the primers look about the same.

http://farm7.static.flickr.com/6169/6187308873_ccce47d67a.jpg (http://www.flickr.com/photos/67211025@N08/6187308873/)

P-32
September 26, 2011, 11:26 PM
I've been reloading about as long as Gordy and I don't see a flat primer. The primers I see, still have a rounded edge. Even if it's ever so slight. A flat primer is not going tp leave a gap between it and the primer pocket. Also checking pressure by using the appearence of a primer is not a for sure way. I did not see any cratering.

ConcernedCitizen
September 26, 2011, 11:41 PM
I've been reloading about as long as Gordy and I don't see a flat primer. The primers I see, still have a rounded edge. Even if it's ever so slight. A flat primer is not going tp leave a gap between it and the primer pocket. Also checking pressure by using the appearence of a primer is not a for sure way. I did not see any cratering.
P-32,

The rounded edge is much more visible in the larger photos. I scaled them down for size, but the edge of the primer still has a radius to it, it's just that the face is flattened on the majority of them.

If you look closely at the far left cartridge in the middle row of the first photo, you can see what appears to be some slight cratering beginning to form. At least that's what it looks like to me, but that's why I'm asking for second opinions!

gamestalker
September 27, 2011, 01:07 AM
+1 Tly999 on the check head space!

If you have shot it enough to know how the brass generally looks, you should be able to narrow down the cause pretty quick. Other wise I would double check my charge weights, seating depth, and possibly consider changing powders.

In the line up of powders for the .308, IMR-4064 is on the fast burning side and is better served up with lighter bullets. Heavier bullets are typically more prone to spiking pressures when using fast burning powders, which could be the problem. Considering you've already decreased your charge to minimum, it's some what evident it's a powder burn rate issue.

A good choice of powder that falls into a slow burner for your application, would be RL17.

snuffy
September 27, 2011, 01:08 AM
FORGETABOUTIT! Reading primers is like reading tea leaves, or having your palm read. They lie! As said, check your rifles headspace, or check to be sure you didn't set the shoulders back too much.

ConcernedCitizen
September 27, 2011, 01:47 AM
+1 Tly999 on the check head space!

If you have shot it enough to know how the brass generally looks, you should be able to narrow down the cause pretty quick. Other wise I would double check my charge weights, seating depth, and possibly consider changing powders.

In the line up of powders for the .308, IMR-4064 is on the fast burning side and is better served up with lighter bullets. Heavier bullets are typically more prone to spiking pressures when using fast burning powders, which could be the problem. Considering you've already decreased your charge to minimum, it's some what evident it's a powder burn rate issue.

A good choice of powder that falls into a slow burner for your application, would be RL17.
I thought IMR 4064 was on the slower side. According to the Hodgdon burn rate chart, most of my available powders fall in the same general vicinity. IMR 3031, IMR 4895, IMR 4064, RL-15, Varget, BL-C(2), and 748 are the rifle powders I have on my shelf at the moment. Any of these that you might recommend?

It sounds like the general consensus is to check the headspace first. I'll track down some headspace gauges soon, just to be safe.

As per Snuffy's advice, I'll also try neck sizing only, to see if that helps. Having a shoulder set back too far could account for the primer having room to move upon ignition, and then being smashed into the bolt face as the cartridge expands.

I appreciate all of the help so far!

Ridgerunner665
September 27, 2011, 02:16 AM
Any of these that you might recommend?

RL-15, Varget...those 2 are my favorites anyway...but all of the powders you mentioned are well proven in the 308 with any common bullet weight.

I don't see anything immediately wrong with those primers...but like snuffy said, one is just as well off reading the walls in a public restroom.

g29guy
September 27, 2011, 02:39 AM
This may sound like a dumb question, but is there a chance you are seating them too hard or flattening the primers with your seater? When I first primed with small pistol primers I over pressed the primers because i was used to seating large primers which take a bit more force. The crushed primers looked just like the middle pictures.
Just throwing that out there.

ranger335v
September 27, 2011, 10:11 AM
"In your opinion, do these primers look flattened to you, or show signs of cratering?"

They look fine to me and I've been reloading since '65. So much as we can really tell anything by primers (which isn't very much) they look like probably full power but not excessive.

Read and heed Snuffy's post, he knows what he's talking about.

Funshooter45
September 27, 2011, 10:40 AM
They look good to me. I don't put much credence into what the primers look like. Only if they are pierced or if they literally fall out after firing do I get concerned. I think a more reliable indicator of gross overpressure is the effort it takes to lift your bolt after firing.

As for powders, once I tried Varget in the .308 I thought I had really discovered the ultimate .308 powder. The reults were outstanding once I had found the best performing bullets. But then... I tried RL-15 :D I didn't think it possible, but it was even better than Varget. That is the only powder I even bother with for 150-168 gr bullets.
For the 150 and 155 gr bullets, you might want to try seating closer to the lands. As in all the way to the lands, just barely touching. My .308 wasn't all that particular about seating depth with the heavy bullets. At first I struggled to find accurate loads for any of the 150 gr bullets I tried. Not even the 155 AMax would group very well. But then I started seating longer and Viola! :) Instant one-hole groups.

NCsmitty
September 27, 2011, 02:10 PM
As some others have mentioned, your loads appear fine. The smoking down the neck on the one case visible is more indicative to me of a mid level load.
According to www.hodgdon.com, at 43gr, you are 1gr above the recommended starting load, and if you're happy with it, then your set.
I've found as the pressures increase, the smoke residue line on the neck moves up toward the case mouth.
Note on factory ammo that the smoke line will be about .1" to .25" down from the case mouth on a properly cut chamber.

It's obvious that your bolt face has some cutter marks that's being transferred to the primer when fired, and that's normal.


NCsmitty

Robert101
September 27, 2011, 02:49 PM
I don't see any issues with the primers either. Flattened primers to me would be a condition where the primer and case meet, thereby, the primer has flattened to the point where almost no gap exists b/n the two.

The primers in the pictures look to have rounded edges.

ConcernedCitizen
September 27, 2011, 03:35 PM
This may sound like a dumb question, but is there a chance you are seating them too hard or flattening the primers with your seater? When I first primed with small pistol primers I over pressed the primers because i was used to seating large primers which take a bit more force. The crushed primers looked just like the middle pictures.
Just throwing that out there.
I think you may be on to something here! I was using an RCBS hand priming tool, and do remember seeing a few that looked slightly flattened after seating. I guess the tool marks from the bolt face just exagerate the problem. I'll try to use a softer touch when priming the next batch.

I'd really like to thank everyone for their input! I felt fairly confident in my load, but needed some way to explain what I was seeing before my conscience would let me continue. There were no other high pressure signs, just the odd and inconsistent primer marks.

Thanks again to everyone for all the help!

gamestalker
September 27, 2011, 04:02 PM
Just to be clear about my observations of your pics, is the primers don't concern me, I load way up there, so flat primers isn't the big thing here, it's the case heads and up that caught my eye. The case heads have a clear indication of transfer detail off the bolt face, it takes quite a bit of the wrong kind of pressure to print that kind of detail on the case and head.

I honestly don't think it is all about the powder either. Try not bumping those shoulders back on that brass. Adjust the FL die enough to size just the neck or use a neck die if you've got one. With well fire formed brass, no doubt that brass is filling every nook and cranny, it is a little easier to diagnose.

Powder burn rate is not properely designated by the manufacturer's line up. Burn rate is specific to the cartridge being loaded. What may be slow burning in one cartridge may be considered a super fast burning powder in another. 4064 is not a slow burning powder for that cartridge.

One last thought, make sure your chamber and brass are completely free of any lube or film from anything, cleaning solvent case lube what ever. Anything on the case or in the chamber can produce some serious problems that will mimic high pressures, by preventing case sieze

Cherokee
September 28, 2011, 02:16 PM
Been doing this for 50+ years, your primers look fine to me. Obviously not light loads, but not excessive either per the primers, which are questionable measures anyway.

brickeyee
September 28, 2011, 04:35 PM
The curve from the face of the primer to the side is still very round.

None of them look very flat.

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