Breaking in a new Benelli M4

Big Bad

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I don't think it's widely enough known that a new Benelli M4 will require a break in before becoming one of the most reliable semi autos around, it seems to be something you have to find out. With my first one, I was told that a box or two high powered shells would have to go through it before it could handle milder target type ammo, this was true, after both the gun and me getting a good pounding from some 3" buckshot ammo, it would 100% cycle anything reasonable I shot through it.

Now about the new one: the vendor told me that magnum shells were no longer necessary and I took him at his word if only because I couldn't find any 3" stuff I wanted to just blow away shooting at nothing. Therefore, what I brought to the range with me was several boxes of 2 3/4" Challenger lead shot shells and a half box of more powerful Buck shells just in case. I also included a short stack of clays to make the thing fun, intending to plant them on the berm as stationary targets. As it turned out, the vendor was correct, the new gun did mostly successfully handle the lower brass shells, something my old one had refused outright, but OTOH the new one did exhibit failures to eject about one in five times- these were mostly of the type where the spent shell remained entirely inside the chamber, real beatches to clear with a new shell coming up and most definitely not the kind of thing you would want to happen in a crisis situation. In the end, which is to say when I reached my limit, this was still happening after quick firing 50 rounds, although less often, and my shoulder was asking me to quit, so I did. I do have to say that at 25m the modified choke completely vaporized the clays I brought, that was fun. I also remain hopeful that just a few more boxes of Challenger will do the break in trick, or if not I will be shooting some slugs to do the sighting in of the ghost ring sights. From my own experience, you just have to stick with it (and BTW my online reading also says that over-lubing an M4 is not the answer). I will post what happens.
 
Check the chambers finish to see if there is excessively deep grooves, which can cause failure to eject by allowing the hot plastic shell to stick too the chamber walls.

If so, give it a light honing & polish.
 
I took my M4 and a Canuck Operator out for the first time. Identical rounds used between clay pigeon loads, 3” buck shot and slugs.

Both guns ran the same. Failure to extract where hull was partially still in receiver.

So, did the M4 run that bad? Or the Operator run that good?
The operator has a poor finish in the chamber, happens with a lot of them.
 
I took my M4 and a Canuck Operator out for the first time. Identical rounds used between clay pigeon loads, 3” buck shot and slugs.

Both guns ran the same. Failure to extract where hull was partially still in receiver.

So, did the M4 run that bad? Or the Operator run that good?
It's just a known thing with Benelli M4s. For whatever reason(s), it goes away after shooting the gun a number of times, and in my experience more quickly with magnum shells.
 
It's just a known thing with Benelli M4s. For whatever reason(s), it goes away after shooting the gun a number of times, and in my experience more quickly with magnum shells.
Agreed, I've had great luck using 3" ammo to break in M4's. Doesn't matter what size shot either. Have switched to 3" steel BB for break in as it's cheapest around here.
 
My son-in-law law bought anew M4 last week. Tried some target loads and it wouldn’t cycle them. Put 75 3” BB through it and went back to the challenger target loads. Worked fine then.
 
My son-in-law law bought anew M4 last week. Tried some target loads and it wouldn’t cycle them. Put 75 3” BB through it and went back to the challenger target loads. Worked fine then.
I gave in and think I just got mine reliably extracting the cheaper, milder fun shells after firing off a single box of 3" shells with 1 1/4 oz of steel shot , which at my age feels like plenty of thumping. That still needs testing of course.
 
Good strip, clean, lube and grease in some spots seem to work well for me.
They are not hard to tear down, I take the recoil spring tube apart get all the #### out of there as well. Grease everything metal on metal, just a light grease and light coat, I had one fail to pick up next round in 75 rounds of weak Winchester 7 1/2 first time out. Everything extracted and ejected fine. 3" buck was pretty warm and no issues, fair fireball even with the standard barrel.
Fun guns.
 
I took a Tactical Shotgun course in July with John Dzurku. I was using a brand new M4. I stripped and cleaned the gun prior to the course. The first 100 rounds fired were Fed target loads. I never had any issues…the gun ran flawlessly.

John mention that if his students had cycling and FTE issues with their semi’s, they were usually running Challenger target loads. It was the only negative thing he said about anybody’s gear/ammo selection.

I’m not sure if John’s comment might play into this discussion.
 
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