Light primer strikes

[va_connoisseur]

Only with one brand of ammo...Hornady Black. After seeing 6 out of 7 light primer strikes today with the factory ammo. I was able to fire 25 reloads, from thrice fired Hornady brass (129 SST, CCI primers, Accurate 2520 powder) with ZERO malfunctions. Instead of throwing out the FTF, I brought them home to investigate. Here is what I found:

I took the measurements of all shells (Headspace, COAL, and OAL) and compared that to my reloads.
The factory ammo averaged: 1.205" (HS), 2.2522 (COAL) and 1.665 (OAL).

My reloads were: 1.2065" (HS), 2.31" (COAL), and 1.699" (OAL). I realize that is with a 129gr SST and not the 123 SST in the Hornady Black.

I also took a picture of the primers of the FTF and 6 randoms from the reloads I fired. That photo is here:
IMG_0751.jpg

Same gun, same day, same magazine. It is obvious which ones fired and which did not. So does anyone have any idea as to why my gun hates Hornady Black? Right now it is all I can get locally but I plan to order other brands tonight. Thanks.

12.7 group buy barrel and bolt, Rise Armament 3.5# one-piece trigger with anti-walk pins.

[Popeye212]

I would be curious if those Hornady Black would fire with a different trigger. Call em send it back.

[VASCAR2]

Just curious which CCI primers you were using?

[va_connoisseur]

I plan on calling Hornady Monday with the info

[va_connoisseur]

Just curious which CCI primers you were using?

CCI 450 primers

[Sticks]

...
The factory ammo averaged: 1.205" (HS), 2.2522 (COAL) and 1.665 (OAL)....

Not trying to be an ass...Did you zero your calipers?

All the factory ammo that I have measured with Hornady Black is 1.1095 (case head to datum line [.350] on the shoulder, 2.242 on the COAL, and 1.510 on the case length.

If those are actual measurements of factory ammo, STOP! Call Hornady, and please post your lot # of the ammo. Hard to believe that they let ammo slip through that was .010 longer in all respects than they should be.

[va_connoisseur]

Not trying to be an ass...Did you zero your calipers?

All the factory ammo that I have measured with Hornady Black is 1.1095 (case head to datum line [.350] on the shoulder, 2.242 on the COAL, and 1.510 on the case length.

If those are actual measurements of factory ammo, STOP! Call Hornady, and please post your lot # of the ammo. Hard to believe that they let ammo slip through that was .010 longer in all respects than they should be.

The short answer is “yes” but I’ll remeasure when I get back to the bench.

OK...back from the bench

Here is the Case Head measurement:

image1 (1).jpeg This was the measurement

This was typical of the remaining 13 cases.

[va_connoisseur]

I measured the COAL of the cartridges again and they were running ~2.251, with the shortest being 2.250.

These were from Hornady Black lot#3182578

[Popeye212]

If those are 450's on the bottom row yes I would be calling Hornady also.