Flatten primers?

[No2sc2]

So what causes flatten primers? I hear its excessive pressure but I bought these "reloads" from a indoor range and I shot them. I didn't check for pressure sign till the 4th round and this is what I found.

This was an indoor range that teaches reloading classes. I asked the guy but he didn't know how much charge was in the round. Besides too much powder, what else could cause this? I also read that flatten primers is a headspace issue?

 

[jglenn]

could be high pressure or soft primers or excessive headspace or ......



ever seen it on your rifle with other factory ammo?

 

[gth813x]

Multitude of things. Typical culprit is the charge is to much given all the other variables.

 

[No2sc2]

could be high pressure or soft primers or excessive headspace or ......



ever seen it on your rifle with other factory ammo?

Nope. Shot my own reloads and didn't have any flatten primers. That flatten primer was from the round the range loaded themselves. No information was given on the load besides it was 147gr. I noticed they seated the bullet almost at the cannelure which means the COAL was longer than 2.115"(my reloads COAL). If I had to guess, it would be around 2.220"+ So I know bullet seating wasn't the problem. However, I did shake the ammo to try to get a "feel" of how much powder and I could only felt a little which means they had very little space in between the bullet and powder.

 

[gth813x]

A "powder test" likethe one you did as it depends on the powder, if you use unique you're not gonna hear/feel anything, if it's titegroup it'll be Floppin around.

If you can feel the powder in a case though, god bless ya cause i cant feel anything like that, especially 3motions.

 

[No2sc2]

A "powder test" likethe one you did as it depends on the powder, if you use unique you're not gonna hear/feel anything, if it's titegroup it'll be Floppin around.

If you can feel the powder in a case though, god bless ya cause i cant feel anything like that, especially 3motions.

LOL well I didn't mean it was a good test. I was just trying to see if it was a compressed load or not. Like some of my 223, I can feel powder flopping around in some and some I can't. Didn't really pay close attention to pressure signs on them because they were all factory loads.

 

[SpeedyR]

I don't think I'd be shooting that in any of my rifles/pistols. I'd take one home and pull the bullet and see if you can get an idea of what powder they were using and or gr of powder might point you in the right direction. those are pretty flattened IMHO, not just a rounding off kinda thing.

were these sold as some sort of +p load or something? flattened primers are usually a sign of over pressure, if you don't see it in other loads that are "standard" or factory loads. Maybe they did mess up the shoulder/headspace on those loads but either way that would scare me.

 

[1006]

Are you shooting 5.56 cases in a 223 or in a barrel marked 5.56?

Either way, an untrimmed 5.56 in a tight 223 chamber might --might, maybe, possibly--cause the pressure to build up.

 

[Junior_357]

Those primers are definitely flattened. Any number of things can cause this, but mainly I would say the following:

1. Too heavy a charge.
2. Wrong powder and primer combination (pressure spike).
3. Wrong powder and bullet combination. Heavier bullets + fast-burning powder will create a pressure spike like an overcharge.

That's my take...and I echo the sentiments of not shooting it through anything I plan to keep.

 

[Crubear]

It could also be nothing except the shoulder is pushed back too far.

When the firing pin hits the primer it pushed the whole cartridge forward to where it's stopped by the shoulder
when the primer goes off the force pushes back against the primer cup, which forces the primer out and back
The powder goes off, forcing the case to return to the bolt face
This flattens the primer

If there are no other indications of pressure; cratered primers, extractor marks, difficult extraction, split cases, etc. Then it's a headspace issue and I'd shoot them for fun, but not use them for something that counts. I'd also go talk to the range about them.