I recently purchased a Faxon 7.62x39 piston upper and their stripped AR lower. I installed a Geissele SSA trigger that ignited Wolf 7.62x39 without problem during the barrel break-in protocol. However, I purchased 500 rounds of Golden Tiger 7.62x39 and that's when the problems began. I had about 15% FTF, although most FTFs ignited on the 2nd attempt. At about the 200 round mark, I installed a Wolff Extra Power hammer spring. I still had about a 15% FTF with the remaining 300 rounds or so of the GT.
In between, I successfully ignited more 7.62x39 Wolf, and then Tula and Hornady SST. Faxon sent me a replacement firing pin and I also tried a Black Rifle Arms enhanced 7.62x39 FP. Same FTF issue with the GT about a 15% FTF.
I used calipers to measure the FP protrusion from the bolt face. I measured from the lugs/lip to the bolt face, and then the lugs/lip to the tip of the protruding pin - and took the difference between the two measurements. The Faxon FP gave the most pin protrusion at .049".
My understanding is that Baranul makes commercial ammo for Bear, Wolf, and Tula - all of which use a SAMMI spec primer for commercial export loads, which is softer the mil-spec primer used by GT. I took a look at the primer strikes on the empty Hornady casings and they did look deeper than the primer strikes on the GT that ignited. Regardless, shouldn't the Geissele SSA with the Wolff XP hammer spring ignite the GT with as much success with the Wolf, Tula and Hornady? Any comments and suggestions will be appreciated!
Here is a picture of 11 rounds (2 that did not ignite)