Unobtanium

I've been really liking the 500 lumen M300C. In 15000 rounds, what has broken, and/or needed service or PM?

The mag spring may not be his issue, as I don't have a crystal ball, but I have had these exact failures back in 2008 before aftermarket springs were available, shooting similar loadings, once I added a 7-shot tube. It ceased when I used a M1 Police spring, and now we have the CC and FFT.

Yeah, the M4 Entry has no ID constriction in the barrel anywhere except the forcing cone. It was hammer forged, imported as a 19.75" barrel with sights welded back, and lopped off once Stateside.

I honestly have no clue. It could be anything, really, based on the lack of being able to examine it, lack of data, and ****, you may not even be ABLE to provide the requisite data because you don't know. It could have been something it leaned against somehow somewhere. I'd write it up as similar to that scratch on your forearm that you don't remember suffering. No real way to tell, at this point.

0.723" is spec. There should be no constriction on your barrel.

Long story short, yes and no. I personally question your measuring device in this case, as that's significant deviation. If the slug is solid like a ball or sabot round, yes, you better keep nominal ID less than slug size.

0.705" is benelli mod. Constriction from bore nominal ID makes the choke, not overall OD.

I've also found that lubing the bore LIGHTLY (sheen, not drops!) helps a lot. I can clean my bore on my SNT with just a bore snake.

My super nova tactical throws Remington sluggers, Truball , and full power buck to the same place. Federal DP goes to the left. Reduced recoil flite control buck goes to the right.

Depends on the slugs, the buck, and the shotgun.

I'm not sure, but I think so. Regardless, they are much harder than typical fosters. Not sure if it's antimony, tempering, or how they arrived there.

A 25 yard zero places me still pretty COM at 100 yards on a B27.

Federal's answer to Brenneke. I have found them to not be the most accurate, and a phone-call to Federal got their opinion from them that they are safe to shoot through MOD, but not advised as long-term use may cause damage. Also note that Federal benchmarks off of Remington, I believe, and Remington MOD is almost a Benelli CYL, in absolute measure.

Yes, but id not use sabot or Federal DP slugs. Regular fosters and most brennekes are fine.

The problem is likely the ammunition coupled with the OEM magazine spring and 7-round capacity. You are using very heavy recoiling ammunition (I have fired that loading before), and what is happening, is the inertia of the gun recoiling, VS. the "round stack" in the tube is causing the round stack to remain stationary, while the gun recoils past it, due to the spring not being strong enough to propel the round stack backwards with the weapon and facilitate feeding. This results in timing/feeding issues. Purchase a replacement magazine spring from www.carriercomp.com, and I am 99.9% sure your issues will go away. www.freedomfightertactical.com also sells a spring that should work, although I prefer the CC spring. It is my opinion that the OEM magazine spring is under-powered for full-length tube capacity when firing 3" or "magnum" 2.75" ammunition. Replace the mag spring, and then go from there. It is the cheapest thing you can presently do, and I don't see anything else wrong with your setup or the way you are running it. My M4's, to a one, would run Remington STS 1145fps 1-1/8oz target loads right out of the box lubed up. Sample of about half a dozen.

What model number M4, and were any parts added after you got it/before you got it, that were not 100% Benelli? What with/how well did you lubricate it before the range? Can you describe precisely what the failure looked like, say, if you handed me the shotgun at the time of failure, what would I be looking at with regard to the last shell fired, and the shell the malfunction is involving?

No, not exactly. Benelli M4 SBS guns enter the country with 19.75" barrels, and sights welded at the correct placement for a 14" barrel. Initially, the barrels were simply cut off and the "tips" left "in the white", and heavily chamfered. Currently, the barrel tips are re-finished to match, and not much of a chamfer is present. Just enough to break the edge and remove any burrs. It is almost like a different gunsmith performed the same "job", and one of the quirks is that the barrels are now not cut flush with the mag-tube cap. But they are re-finished and not left "in the white", so take your pick... The change occurred around the time of the polymer trigger guards, as I understand.

Can you change your grip? Is your grip proper? I'm not saying you are the problem, but you may have to change if you're to make the gun work for you, or modify the gun.

1.75oz is too much. You must use 1.56oz as you note.

It's new vs. Old. Notice yours is likely finished and not bare metal on the cut surface.

Congrats! Rare edition.

ITAR prevents you from even allowing a non us citizen from merely looking through a gen 3 nvd.

That's a Benelli M4-A1 Entry model. Not for sale in America currently.

This is a recurring theme, here. Also, TTI has other fires to put out: (****, not gear, is what they are experts in, and they are bad judges of that, too, apparently)

Well, ask yourself this...what agency is issuing RMR's for carbines or PDW's? Okay, what about T and H series type sights? I just piggyback on those who have put in the tests, etc. I am also a glass snob, and the T2/H2 has no dot distortion near the edges of its CLEAR window...