u/Diligent_Wishbone_99

Hey guys I have a benelli m4 I’ve been tryning my hardest to “break in” I’ve shot 440 rounds through it so far mostly the heaviest duck pheasant buck and slugs I can find to break it in. It mostly functions ok while actually firing however it has a major issue on every reload and also it does it once in awhile while shooting. Now I’ve taken it fully apart excluding the trigger group internals 4 times basically every 100 round range trip I’ve been fully degreasing and heavily relubing everything to rule out anything lube or cleanliness related. The “ jam”clears if I smack the bolt handle forward with my hand ( sorta like it doenst have enough recoil around tension but I’m sure it does)

So tonight I took it all apart again to try to look really good for any abnormal wear spots and degrease and maybe try to polish a few spots carefully. So I found many spots with abnormal wear and wondering what some gunsmiths on here might think which area would be the problem I need to fix I don’t really wanna have to pay to send it in and wait months to get it back and so far customer service has been absolutely terrible just ignoring my questions.

The bolt tail has some sharp edges mushrooming at the rear that keep getting worse every 100 rounds.

The bolt carrier latch has some wierd edges on it where it seems to be biting into the bolt release/ shell latch.

The trigger group has a heavy worn line in it that kinda coincides with that.

There’s a little dent in the bolt carrier group looks like they dropped it lightly at the factory maybe before finishing it.

By the follower there’s a pretty worn area looks like where the shells come out maybe that’s bare aluminum

Typical wear front if the bolt carrier where the 2 pistons hit. But also a 3 spot that’s quite scratched on that face.

The bolt carrier slides freely in the rails with trigger group out all feels well there

The hammer and the shell lift lever ( I don’t know the correct term) both have a little peening on them

Gun is run dripping wet with good lube each range trip to rule out any dryness issues and completely stripped of any dirt or old lube each trip.

What would you think would be catching ? The tail in the recoil tube?
The brass colored shell lifter sharp edge catching on the bolt release/ shell latch?

I put a picture of what it’s doing on a reload a sharp smack lets it chamber 3/4 the time it runs without jams for the 7 shells but in the reload you gotta smack it and maybe 5 out of 100 times it jams.
I can grab more pictures of the wear parts if needed. I’ve only found maybe 2 other threads on the whole internet with this issue and no resolution been trying to figure this out for months less

I’ve owned or seen a good amount of 500 or 590 series shotguns can anyone confirm if these sharp edges in the hole of the barrel lock up are correct? I remember it just being square but there’s 1 or 2 of these sharp triangular angles. My shells are also sticking in the chamber so just polished that up a little. Is is supposed to be not square like this? Picture included