So I cleared my firearm to strip and oil. I have not been to the range in probably 6 weeks between work and mountain weather. When reassembled and chambering a round it didnt want to seat leaving the slide back just enough to see the round. I inspected the round to see if any deformities and noticed it looked unnaturally short. The round in question is the one that has been chambered and remained chambered for almost the entire time since my last range day. They are the Sig V-Crown hollow point 9mm. The question is, should I be cycling chambered rounds/not leaving the same round down the pipe for long periods of time? Has anyone else had this issue? Is this round still safe to fire or should I toss it?
Gun is Sig P320 compact
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Hello and welcome at @MurphsLaw242
I have had that same problem with their 9mm ammunition OAL.
As far as the slide not going into battery with partial case showing that happens when the case hasn’t been sized properly.
Was it difficult to pull the slide back to get the case out?
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This was my +1 round so i did the drop in method so the slide didnt travel enough for the extractor to have a chance to grab the casing. I didn’t try feeding it through the magazine as i basically dont trust the round at this point. As far as feeling “too tight” in the barrel so to speak it fell out simply by turning over the firearm. There was no bulge of the casing that i could tell.
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When I switched over my SD rounds from the Sig V’s I shot the rest off, even the shorter ones. They went off with no issue, I just didn’t feel at ease thinking they may not feed well when I really needed them.
Hth
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Welcome to the Community!
Have you tried feeding other rounds through the magazine after this event? Have you tried loading other rounds using the “drop in” method? The reason I am asking is the OAL of the round should not affect the drop in method of loading, but could be an indication the extractor is slightly bent inward causing it to catch on the back edge of the case and keep it from going into battery. I personally never use the drop in method because of my fear of damaging the extractor when it impacts and jumps over the edge of the case.
To @Karacal 's point, it could have come from the factory with the bullet pressed deeper into the case. Or, noticable bullet push back occurs when the same cartridge is loaded repeatedly from the magazine due to impact with the feed ramp. This would not occur using the drop in method. Either way, the pressure when fired will be increased by seating the bullet deeper into the case.
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Other rounds fed fine as i was checking functionality to ensure it wasn’t an issue in any of the feed mechanics (slide, barrel tilt, etc.) Field stripped and reassembled to double check my steps to ensure it wasnt a fault on my end. As far as “drop in” method i have only done it a handfull of times out of laziness. Though i do like that you mentioned extractor damage as honestly I never considered that a thing simply because no one has ever talked about or mentioned it to me; so something I will certainly take into consideration from here on. I did a controlled slide release when trying to chamber the round, I normally do not slap the slide. After removing the questionable round I did controlled and snap slide releases to check feed function and had no issues with the other rounds in the magazine.
Also, I do inspect any ammo that I purchase before loading them, call it paranoia or ocd but its just something that I look for. If i find an ammo that is consistant in cycling and grouping i do not stray for price point.
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I have not had that issue myself.
I have seen reports of that issue with lower quality ammo and handloads mostly.
It is sometimes blamed on chambering the same round multiple times. Leaving it in the chamber is not an issue. Actively chambering it (and thus ramming it into the feed ramp) repeatedly might be an issue.
I recommend chambering rounds the way they are intended to be, up from the magazine and then full force of the slide. Lock the slide to the rear, insert mag, release slide. But only do it once per round especially with manufacturers/rounds that have shown this failure with your gun
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Toss it, increased pressure could damage your Sig and you.
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BTW the term for that, if you want to go search about it and read, is bullet setback or set-back.
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I stopped the drop-in method years ago. The last time I tried it, the slide did not go all the way foward, as the extractor impacted the base of the round. I realized what had happened and retracted the slide to eject the round.
The round would not eject as the extractor had not “grabbed” it, so to speak. I plucked out the round with my fingers. I noticed that the base of the round had a small crease in it from where the extractor had inpacted it.
I now only chamber a round by racking the slide, feeding it from the magazine. I read after the fact that the drop-in method can indeed damage extractors and cause the pistol to not go into battery.
I had never read or heard about this issue prior to it happening to me. It was just another example of the myriad of small facts that come with owning a firearm. Regarding your damaged round, I would not fire it. You should discard it in my humble opinion.
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Repeatedly chambering/re-chambering any round can shorten it. I think there is a separate thread on this subject. When I remove a round from the chamber, I put it in a separate cartridge box. When I fill the box, I check each round with calipers and return the round to service if within spec.
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Some manufacturers specifically recommend not using the drop in method because it may damage the extractor.
I’ve been keeping an eye out for set back lately with my SD rounds since the ammo price increases have lead me to not shoot off my SD rounds every time I go to the range like I used to and I’ve been loading and unloading more often for dry fire practice. So far I haven’t seen any set back issues with the SD rounds I’m using but I’ve never tried the Sig options and I do try to rotate the rounds in the mag so I am not reloading the same one each time.
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Welcome to the family brother @MurphsLaw242 and we are glad to have you here. I did experience the same thing so I do rotate my chambered round and they are Sig V crowns. I noticed it was deeper into the casing making the round look shorter than the others. As a matter of fact when I shook the gun that round rattled inside and you can hear it. I suggest that every once in a while, you check and rotate the chambered round.
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I have the Hellcat Pro and they specifically state not to use the drop-in method because it will damage the extractor.
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If you use the drop in method frequently with the same round it is a possibility that the slide dropping forward on it can loosen the bullet head from the casing. I have used that method before but not often.
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Use a 9mm bullet gauge and it should drop in and out with no problems. The length can also be checked with this gauge.
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Thanks for reminding me I picked up a gauge a while back (right after I did the caliper route last time). Much more time effective.
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its called bullet setback and its usually caused by people repeatedly chambering the same round over and over again. it happens a lot with self defense rounds because people will unload their EDC CCW weapon to practice at the range, and then put the exact same ammunition back in their magazines once training has concluded. not to say that you cant use that ammo anymore, but care must be taken with any rounds that have been repeatedly chambered. by function of the way the ammunition strikes the feed ramp it causes rearward pressure on the projectile as it rides up the feed ramp. this force usually isnt enough to cause an issue, as it generally only happens once, but the projectile repeatedly hitting the feed ramp can cause projectiles that dont have a good bullet crimp to eventually compress into the casing. this can cause some significant overpressure issues, especially in +p carry ammo. the easiest way to avoid this is to shoot your carry ammo relatively frequently. ammo that has been repeatedly exposed to excessive heat cycles that could cause condensation/moisture issues shouldnt generally be trusted with your life to begin with.
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Bullet Setback Fears | RECOIL (recoilweb.com)
heres an article from Recoil magainze on the topic
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Agree 100 percent. The bullet head gets loose on the rim of the casing due to repeated chambering.
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