Primer Problem

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velocette

velocette

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9mm target loads, 3.9 gr Bullseye, RP # 1& 1/2, small pistol primers, 125 gr Missouri cast lead bullet mixed brass..
Top rounds fired from my Sig 229, Lower ones fired from my Browning Hi Power.
Same day, same load. None of them were louder or stronger or in any way different from normal.
Primers are not flattened at edges, but the firing pin dent is flattened out and appears to be scraped by the firing pin hole. Small fragments of brass found inside the firing pin return spring on the BHP.
Seen this before? In 40 years of reloading & hundreds of thousand rounds, I've never seen anything like this.



 
Wrong primer. Use 5 1/2

Remington.jpg
 
According to Remington, the #1 1/2 is the standard non Magnum primer, and thus, is appropriate for 9 mm.
It should be fine in 9 mm... unless your load is hotter than it should be.
 
The difference between 1 1/2 and 5 1/2 is the hardness of the cups.
Softer cups will seal better at lower pressure, preventing gas blowing out between the primer and the pocket. This leakage can cause gas cutting in a little circular ring on the breechface.

At 9mm pressures, 5 1/2 presumably seals fine, since it works with 40SW.

So, double check your scale. Double check your load book. If no other signs of overpressure, I'd change primers and call it a day. I've shot over 1k regular pressure 9mm loaded with CCI400 rifle primers and have no gas cutting on the breechface.
 
3.9 ~ 4.0 gr of Bullseye propellant is WELL under Alliant's 9mm 125 gr lead bullet maximum charge of 4.9 gr. Scales, both digital and balance beam have been calibrated.
The primers cup was probably too soft, maybe left in the annealing oven too long.
I am changing primers to CCI, of which I have never had this or any other problem. The remaining 1 1/2 primers will be used for .38 spl target loads.
Your responses have been in agreement with what I checked and found. Saami pressures for the full power 9mm are darn near that of .357 mag and the same as .40 S&W.
Thanks.
 
velocette said:
3.9 ~ 4.0 gr of Bullseye propellant is WELL under Alliant's 9mm 125 gr lead bullet maximum charge of 4.9 gr.
Click to expand...
If its not a primer problem?

The 4.9 gr maximum load would seem to be old data for around 2005, by my old Alliant factory manuals. But your well under that at 4 gr.
The Alliant data lists a bullet of 125 gr L only, with a COL, but not knowing the shape of the bullet used for the data, may make a difference?

A short COL, with the Missouri bullet shank deep into the case would raise pressures?

I would check the brass trim length after sizing, but i doubt thats an issure? I only bring this up because of seeing a 45 acp with a short chamber. A reamer corrected the chamber and the problem went away. Primer looked same as yours, but in 45 acp.

Let us know it a mag primer fixes it.
 
Check to see that you did not get bullets that are not .355 in diameter. Larger diameters will raise the pressure independent of the amount of power used. Also, larger diameter will generally allow lead build up faster.
Also, as others have noted, verify that you power drop and scale are doing their jobs correctly.
 
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