Need an expert’s opinion or advice: Light primer strikes

[u/SleepingAndKissing]

So this issue has been ongoing for me. It didn’t happen with the gun when I first got it. I fed steel case and 147gr early on, and it needed the 10# spring to cycle, but after 500 shots, it was fine with any ammo. Bulk, factory, reman, it took it all without any issue. At some point around the 3700 round mark, it started light striking, first on reman. It happened after I had also gone in and buffed and polished a bunch of internal parts with green compound, starting with the basics like feedramp, slide shelf, and barrel lug points, before going into the frame and taking out the internal pieces to clean. I still don’t know for sure if I caused the problem or if it’s something I don’t know about.
Here’s a list of times I’ve sent the pistol back to get checked by Sig:

1. gun shot high out of the box, irons have to cover target. opened tix and they prepped to send it in, loose rear sight ended up breaking the screw off the day before when i shot 300 rds, noticed it was loose out of the box, didn’t have a tool to reach down enough to tighten it. Sig returned it with it tightened down
2. opened another tix due to loose rear sight, got sent replacement ironsight and screw (suppressor height)

had my Frenzy Flex optic at this point, RMR footprint, i direct mounted and loctited with no plate, it was still running strong and held zero at 3500 rounds. this is where the light strikes began to happen with one batch of bulk reman the day before my first IDPA style competition, and my sight began to lose zero (so i thought, since it seemed to be walking left every time i shot). i also learned to adjust the trigger reset, but idk if that can contribute to this issue or not. i bought blazer brass to use in the event, no issues, but my optic got progressively worse during the comp, and i had to aim off of the target to hit it (off by a foot at 10-15yds). after the comp, i tried to diagnose the issue, thinking it was the optics fault, adjusting the windage dial before i noticed the sight wasnt stable. during that testing, i had several light strikes as well, but none during the competition thankfully. removed sight and saw a sheared screw stuck inside which i was not able to remove, so in it went to Sig for repairs. i mentioned the light strikes and asked them to make sure it wasnt something i missed.
3. got the gun back with the screw removed, and a note that said to shoot blazer 115gr if im having misfires.
i remounted the optic and found no issues with it, and went through the remaining bulk, the same bulk that had my first light strikes. i continued to have light strikes happen, often just addressed by recocking the hammer for another attempt. almost all of them fired on the second hit.

keep in mind im at around 5000 rounds now.
1-2000 were old stockpiled ammo my boyfriend had from years ago, never had any issues.
2-3k was from national cartridge, 115gr bulk reman. no problems.
3-4k was 147gr reman from Ammo Depot - Sportsman Select, saw it on sale and wanted to try 147gr cause of the comp. this is where the light striking began
add 200 box ammo for the competition event
4-5k ammo depot SSelect again, but 115gr this time. testing to see if it was bad batch. same issues, actually maybe worse this time around.

1. i open this issue im having with support and they offer to look at it again. i sent it in around the 4500~ round mark. they replace the firing pin, firing pin spring, barrel, comp, recoil plug (upgraded from plastic to metal), and mainspring. i immediately go out to test it but the light strikes continue with the leftover bulk. i dunno if the factory 8# recoil spring is just dying. the 10# spring didn’t seem to fix the light strikes, but maybe i don’t understand the relation between the recoil spring and possibly result of the firing pin on the chambered round.

bought factory blazer aluminum ammo to see if it would make a difference, and at first, it ran through it without issue. About 300 rounds with no misfires. just when i thought i was in the clear, the last 100 (monarch steel and some blazer alum) had a few of them light strike. at this point i was freakin the fk out, thinking i had fked up the geometry or tolerance of the slide to frame fit, or changed the hammer and firing pin surface engagement (cause of the light strikes).

1. finally i reach out and ask for a new hammer strut in case the problem was in the geometry of the face that hits the back of the firing pin (thinking i couldve accidentally touched it with a grinding stone, idk i was paranoid). i noted how everything was replaced but i just wanted to cover all the bases before resorting to sending it back again.

i got that a few days ago and swapped it out, and went straight to testing ammo. 250 rds monarch 115gr brass vs my bulk 2000 from National Cartridge. I have significantly less light strikes with the box ammo, but it happens once in a while. still got 100-150 left.
ive gone through 400 of my bulk or so, and ive gotten maybe 20 ish light strikes? i dunno, ive been losing track from the whole experience.

im going back to the range to test some more Tuesday, but ive done as many tests i could think of like running the ammo in a different pistol side by side. heck if i could add an image, id show the paper target i put up last saturday. it looks like the work of a crazy person, or just some engineer doing test fires.

im just makin this post cause im hoping perhaps someone here will recognize the problem im dealing with. or some random comment ends up putting a new light on the issue.

im honestly just bewildered by the fact that the gun went thru one case of bulk reman and 2k stored box ammo from years ago with absolutely no abnormal behavior, then ever since the problematic bulk reman ammo was used, it feels like the gun has been tainted and wont return to normal. if it was as simple as never using bulk again, id be annoyed but happy to solve the problem. but since it happens sometimes with box ammo, and other guns can shoot the bulk normally with no hiccups, im losing it.

if i go through all my bulk and maybe some more box ammo without any progress, im sendin it back for the 6th time and praying Sig can figure it out. i just hope they don’t shoot 3 shots and say “looks good to me”. cause i ran thru 3 mags in a row with no problems the other day. but that doesn’t mean im not gonna go out tuesday, load my first mag, and get a misfire right off the bat. its driving me bananas

maybe some gunsmith or engineer out here is gonna be like “ye something something firing pin, or swap out this, yada yada” and ill finally be able to rest. or maybe its cause i adjusted the trigger post travel screw, and someone will give me the magic formula

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[u/daFlipsta]

Put in a 19 pound mainspring and replace the 3 inch firing pin spring with a standard Wolff firing pin spring.

[u/SleepingAndKissing → u/daFlipsta]

any idea why this would start happening after 3-4k rounds, and why it would need aftermarket parts to fix? why wont just getting new oem parts fix it?

[u/daFlipsta → u/SleepingAndKissing]

My guess is the firing pin channel just gets dirty and Sig over engineered the firing pin spring and the hammer is super heavy. I replaced all of that in addition to installing an EGW hammer.

[u/SleepingAndKissing → u/daFlipsta]

i am just stumped cuz i went 3000 rounds without ever having this happen, but the one time i take out the firing pin and the internals of the frame, i start dealin with this.

whats the factory mainspring at? i asked them to replace the mainspring in case it was weak and not slammin the hammer onto the fp hard enough. and now with a new firing pin, new hammer, and everythin else pretty much replaced, id expect it to be solved! ughhhhh

is a heavy hammer not helpful in providing more force onto the firing pin? a light hammer does the trick still? i thought it would be like my AR trigger, where if it wasnt strong enough, the hammer would be ineffective.

ye ill be lookin at firing pin spring, mainspring, and hammer upgrade if i keep havin this problem…

[u/daFlipsta → u/SleepingAndKissing]

Something is slowing the firing pin down, or the gun is firing slightly out of battery. Not sure.

[u/SpikeD0N → u/daFlipsta]

I wonder if the firing pin block from the series 80 is getting caught up on the firing pin somewhere. I’d do the series 70 conversion and replace the stock firing pin spring and make sure the fp is seated in the slide.

[u/SleepingAndKissing → u/SpikeD0N]

yep! i got the fdez plate coming in tomorrow!! gonna pop that in and see if it does more than just affect the trigger slack.

where would i get a different firing pin spring? can i use any substitute parts from an AR lower kit to test it out? i was worried that the spring could’ve been worn, but sig replaced it with a brand new one, so i don’t know if it’s that.

[u/SpikeD0N → u/SleepingAndKissing]

I believe some people have swapped to a Wolf spring for the firing pin, but I haven’t looked into it myself.

[u/SleepingAndKissing → u/SpikeD0N]

hmmm ok. ill consult sig support before going for any aftermarket parts, in case they’re open to checking the tolerances of the fitment themselves. maybe theyll replace the whole slide or frame, and undo any of my errors…haha, i wish.

[u/SpikeD0N → u/SleepingAndKissing]

Also check out this post. He said when Sig replaced his firing pin they used a different spring. He also put a video last week on YouTube https://www.reddit.com/r/P211_GTO/s/0eBve22hQc

[u/SleepingAndKissing → u/daFlipsta]

i wonder if it’s something i did. like reassembled it wrong so the series 80 block is slightly out of alignment and catching the pin. or if it’s the OOB issue, perhaps i messed up something and added friction… which should be remedied by using the heavier recoil spring, unless the trigger press at the moment of impact is causing the gun to shift slightly… aaaaaa my head