Loaded TOO HOT -what does it look like?

[Glennster]

Does anybody have any pictures that show what brass looks like when its been loaded too hot???
I've heard some talk of flattened primers, heck they all look flat to me.
Pictures would be greatly appreciated. A description of what to look for would also be great.
THANKS!

 

[Grumulkin]

Reloading manuals generally have photos of things like this and give more detailed explanations.

Also, you can't go just by the appearance of the primer in determining whether a load is too hot. The type of cartridge (straight walled vs bottlenecked), primer size (large vs small) have to be taken into consideration. Furthermore, there are guns that should only be loaded with low pressure rounds and going only by primer appearance could (probably would) give you a gross overload.

The following are things to look fore in a primer:

1. At the edge, primers have a small curve. As long as most of this curve is preserved, the load is probably conservative.

2. As the load is increased, the primer flattens more and the small curve is obliterated. This shows the load is substantial but not necessarily an overload.

3. There may be a tiny raised ridge of metal around where the firing pin indentation is. This is because metal has been pressed into the little space around the firing pin. Whether or not this occurs and to what extent, depends on how tightly the firing pin is fitted in the bolt and doesn't necessarily mean an overload but the maximum load is being approached.

4. The primer surface as the come from the box, is smooth and shiny. When they cease being shiny, that means they are receiving tiny indentations from the bolt face and the pressure is rapidly approaching maximum.

5. When you really have an overload, you can get pierced primers or a gas leak around the edge of the primer. If you get these signs, you have a definite overload. Back off and don't shoot any more loads this hot.

6. Sticky case extraction means the load is a bit too hot but of course this has nothing to do with primer appearance.

 

[NuJudge]

Don't just look at the primer. For rifles with an ejector in the face of the bolt, look for displacement of metal into that space (this indicates high pressures).

The only pictures I've been able to find quickly of primers is under the "Reloading Stuph" hyperlink here:
http://radomski.us/njhp/

 

[jfh]

here's a picture or two

of primers from a load that was about 17-18 gr. of AA#7 under a Lead 140--in a 38SPL case. It was a reloading error, not a double charge--and it took some minor detective work to determine what had happened (other than the reloader--that's me--not being familiar with AA#7 recently).

http://www.pbase.com/jfh1945/image/82483587

As you may know, a 38 SPL+P load tops out at 18,500--some one else has calculated the pressure for these cartridges was 55,000 to 72,000. I shot a cylinderful in a S&W 640--the 24oz SS snubby in .38/.357. The recoil was awesome, but entirely controllable--sort of like a tsunami coming at you.

The gun held together, obviously, and I even shot another 80 rounds or so of low-medium .357 loads, but with sticky extraction. Examination by my gunsmith revealed a stretched cylinder (see the other pictures) and S&W ended up putting a new cylinder and barrel in it.

The primers are WSPs--and they really don't look that bad, IMO. The brass was new Starline (maybe fired once), and the heads separated when I tapped them gently with a range rod. Note that you can even still read the case head easily.

I've seen primers like this before, and pictures of others that looked much worse. Somewhere there are pictures from the .223 loads one of the Armed Forces team uses in long-range competition--and those are melted and the case heads smeared.

The point is, as others have said, I now am not convinced one can read primers very readily for overpressure signs.

Jim H.

 

[Slamfire]

http://www.thehighroad.org/showthread.php?t=296462

Examine the pictures in this thread.

 

[Misfire99]

For what it's worth primers blowing out are not always a sign of high pressure. I have an Enfield No4 Mrk1 that was blowing primers. I would get a nice jet of gas out of the port on the left side of the receiver. I knew that the ammo was not at fault and checked everything I could think of. I checked to see if the firing pin had gotten sharp somehow and was piercing the primers. No that was not it. Then I checked the head space. Excess head space is not supposed to blow primers. But I put a longer bolt head, a number 3, and the problem stopped and it shot just fine. My point is you can't always trust that your primers will tell you the complete story. For high pressure sign I look for hard extraction and brass flowing on the head stamp. But if you shoot military steel cases you will not get the same flow patterns on the headstamp. I have some 7.62x54r ammo that seems to have been made for machine guns. I fired a round of this stuff off and had to use a mallet to get the bolt open. The case was steel and I didn't see anything that look "bad" on it. I wondered if the lacquer was the problem and popped off another. Same problem and it had a definite recoil to it. I stopped using that ammo and still have it in my locker.

 

[Harley Quinn]

This thread will help you I would hope

http://www.thehighroad.org/showthread.php?t=296462

Oops same one as above LOL...

HQ