So this is new.  Let's take a stroll with me on this one.  I'm going to make a long walk - because it's the weekend.

I picked up a Stribog SP9A3 for a good price a couple years ago.  And it's the latest one, with the >4000 SN parts in it, so it runs quite good.  Remarkably good.  But, shortly after buying it and looking around the internets, people recommend a replacement impact buffer, safety switches, and hey, while I'm there, I'll grab one of those 3rd party little muzzle break things barely bigger than the thread-protector nut already on the gun.  Same size (ish) and reduction of that intense 9mm recoil ( )   And most importantly, it replaces a part with no function, with an equal part with some (ish) function.  (because that's how I roll).

As a minimalist, I really like the little comp-rig, lots of people use it, it's tiny, it's cool, it even has a spiffy built in rubber ring to help keep it from walking off on you (which my bare factory muzzle nut did constantly).

Take it out, load up some 9mm ammo, and start field shooting.  Man this gun is GREAT!  love this thing.  Odd though, it kind of spit at me from the muzzle those first few rounds.   No doubt some unburned powder from my slow CFE powder that my P7 doesn't like either, I guess.  There we go, proof that my compensator is directing gas back.  No big deal.  And look at that, it stopped doing that after a few rounds.  Which now seems odd, but at the time, perfectly normal - nothing to think about (ah the mindset when actually afield).

18 months and 3000 rounds go by.

Gun shoots great.   The muzzle device isn't wearing so good - kind of odd and .. lumpy, on the inside when I borescope my barrel.  Must be a fouling thing I guess.   Gun's pretty accurate, but sometimes it does these weird flyers.  And when I change bullet profile in otherwise similar loads, I can get odd POI shifts.  Ah well, guns have personalities.  My MDRx and AUG shift points of impact pretty extensively too with ammo changes; and the RDB has the one-flyer-every-5-rounds-FEATURE - so nothing remarkable or a big deal, just make a note of that.

Ammo continues to flow through the gun.  Runs great, accuracy is good, doesn't spit at me at all anymore now - no doubt to my improved powder selection I'm running (I reload).  I'm such a good reloader - so clearly that's my improved reload recipes.

A couple weeks ago, I decide it's time for a detail breakdown and cleaning.  I take the gun apart, pull off the comp.  My muzzle is coppered up, but otherwise good.  I really should clean that well.  And man, my compensator is just a mess.  Look at this, that thing's diameter from all the fouling build up is barrely bigger than the muzzle.  In fact.. is it any bigger than the muzzle.  Oh man, are my bullets hitting carbon fouling here?  Let me grab a bullet and test that..... annnd the bullet won't even fit through the comp.  Soo......    Hmm...  The 3000 round count comp diameter, is smaller than the diameter of my 9mm bullet.  Wow, that's a lot of carbon build up.  And.. are those scrapes in it?  I'll just pull out a copper bore brush and... dude, that's not carbon, that's metal.

Ever have a moment where you stop and go: "well that's not right"?  Which in retrospect, was a whole lot later than you should have?  This was finally that moment.  

So, I reach out to the vendor I bought it from (>1 yr - 18 months ago) and ask: "hey, was there ever a recall or anything on these things - here's a picture of my live round where a bullet doesn't even fit through it.  Is it supposed to be like that?"

Answer within like 2 hours: "There haven't been any recalls that we know if, but that doesn't look right at all.  I'm sending you a new replacement right now"   (no bullshit.  no Sir, Sir Sir, please provide a receipt less than 12 months ago and pay $20 SH and and and; none of that shit.).   My opinion of the company is actually quite high from all this.   New one shows up in like 2 days flat (tbh, I think it might have been just 1 day).  I take it, and an entire live 9mm round including casing, falls right through it.  

Install and ran a few hundred rounds this week.  My gun that used to shoot pretty good at 100 yards


which is pretty good actually.

Now shoots like THIS at 100 yards, and this is with cheap shit off-spec dissimilar bulk salvaged bullets from AM Rel.

Which is just remarkable.

So... right!
To state the obvious, I'm pretty sure somewhere somehow I get a 7.62mm spec muzzle break - or a factory defect.  Who knows who's fault - maybe the vendor, maybe the manufacture, maybe ME, maybe I somehow clicked on the wrong SKU (I don't think so, but hey - who knows).  What I do know is that vendor immediately recognized that wasn't right and took care of it right away with no bullshit.  

The other part of this, obviously, that "spitting" was the initial 9mm rounds I was firing were impacting the muzzle device, and blew it out (internally - externally nothing was amiss at all).  And the "spitting" was the copper jacket shavings coming back at me.  Stribog handled it fine, and didn't care - go go roller delay I guess.  I find it remarkable the gun was any where near as accurate as it was, considering bullets were scraping and contacting that thing for pretty much all 3000 rounds.  Yet, I was able to decently hit gongs at 200 yards with this little 8" 9mm PCC.  


I feel like the recoil seems smoother now - but that could be in my head from all this.  What I can say, is the accuracy is measurably better.  I'm getting 2.5 MOA out of this gun at 100 yards now.  I have rifles that can't do that.

So ... wow, feel kind of dumb not keying in on some of those now telling clues, until only recently.   Though I suppose, as a patent attorney once told me (on "obviousness" exclusions on patents) "it's obvious NOW, now that it's been laid out and explained while you're sitting down -  it's totally obvious even a blind man could see that ... now".  

It happens. That almost happened to me on a Keltec sub 2000. A buddy that was with me caught it before we shot the new gun.  

Glad you didn't have any bad results. My gen 1 stribog has been a great gun.

Muzzle devices come designed for a specific caliber and specific thread pattern.

.223
.308
.355…….9mm

They can be bored out larger with a lathe sometimes that works well sometimes not so much. I have a smith vortex bored out from .30 cal to work on a .44 mag Henry X rifle. When it was bored for .375 H&H it caused an irregular pattern. Go big or go home.

Somebody's CNC had the wrong tooling loaded and no post machining QC.

I had a similar thing with an aftermarket safety for a Hellcat. It was obvious that the tool went away or broke. I contacted them, they acknowledged they had a problem and they were running fresh parts, and would send one out when done. About a month later I got one in the mail with the identical problem the first one had. I threw them both in the trash and moved on with my life. Maybe the problem was programming not tooling, I don't know

Jeebus that is scary.  I will never attach a new muzzle device without checking going forward.

I had an MP5 FH that wouldn't let a 9mm round drop through it.  I sent it back before even trying it.

9mm PCC's probably shouldn't be the common .223/5.56mm 1/2x28 thread pitch.  Too easy to mix things up.  Not sure what happened in your case, but when companies offer the same muzzle device in different diameters and thread pitches, anything can happen.

Let me guess... Smith Enterprise's "Vortex" 9mm 4 prong?

I only ask because the same darn thing is happening with mine!