Steve Rose

What brand and type of ammo are you using when the problem occurs? If it is the Winchester "Universal" or their similar promo ammo (silver metal rims, ribbed red plastic hull) its an ammo problem.

Has it always had this problem, or did it start after some period of working well? Which brand and type of shells are you using ? What is the shell's velocity and shot weight? Have you ever removed and checked the inertia spring inside the bolt carrier? (There was a run of Stoeger inertia springs a few years ago that would break)

The NFA/ATF no longer requires a CLEO sign off (as of July 2016) ...but it does not matter in this case. As far as I know New York does not allow Short Barrel Shotguns (less than 18" barrel) https://www.nationalguntrusts.com/blogs/nfa-gun-trust-atf-information-database-blog/new-york-state-nfa-rules-and-allowable-nfa-items

On the 1301 the lifter drops when the hammer falls. What makes the lifter drop on your Benelli mod?...or just go shoot it, I want to see it work! ?

Yep, the hinged 20ga latch holds the shell just a bit father forward than a 12 ga latch (and can contact some followers)...and don't try to drill & tap the 20ga latch for an oversize release button.

Can you go directly from loading the mag tube to shooting, or do you have to pull the bolt back to get the lifter to drop first?

M4 factory barrel. (The short M1 barrels are quite a bit thinner)

The Nova follower is stepped down in diameter. The M2 follower is not - so it will not travel to the end of the mag tube on the last shot (lacks about 5/8”). You'll have to go to Nordic or RCI/Roth Performance for a metal Nova follower.

We (Rose Action Sports) have threaded several of the short factory barrels for Rem-Choke or Mossberg Accu-choke tubes.

Are you sure the width of the hammer is the issue? A hammer disconnector hook that is too tall can hold the hammer back like the picture you posted – but you will NOT be able to pull the hammer back up the correct position after cocking the hammer. If you CAN pull the hammer up into the correct “cocked” position then the “too wide” diagnosis is probably the right one. Coat the hammer with a black or blue Sharpie marker then install it. Functioning the hammer a few cycles will wear the marker color and show you where any contact is occurring.

Compare your gun's hole spacing to this (picture from the EGW web site): Scope base hole spacing for the Benelli scope base (same as a Weaver 93)

@Jimbo45 Was that a M1 barrel, or M4 barrel ?

It is really just an extended and ported choke tube with wicked looking teeth on the end. The “no slugs” comes from it being an “Extra Full” constriction. Carlson also marketed a Cylinder constriction tube in the same style that was OK with any shell type. Both are showing "out of stock" at Brownells and Carlsons

In my experience the Remington "Gun Club" ammo is the best of the lower priced stuff.

That is normal.

One other thing....I have seen some of that cheaper Federal ammo that has slivers of the plastic hull protruding around the metal rim. That can cause the shell to not seat fully into the chamber and stop the bolt from closing. Inspect a few boxes of shell to see if your ammo exhibits that problem. I used to use the WalMart Federal ammo too but started having issues with its quality. I now use only Winchester AA ammo in my M2 and SBE. Yes, the ammo is $2 a box more expensive, but ammo related issues just don't happen now.

When on the line and loading his gun is your Grandson placing a shell into the receiver then pushing the bolt release button to let the bolt slam shut? (That is the way to do it). If he is holding the bolt handle to let the gun close slowly, or in any way hampering the gun's bolt from closing, that may be the cause of his misfire problem.

I looked at a couple of Benelli bolts today and did not see any with that mark. Given the location I suspect that the assembler missed the mark and hit the edge the bolt when driving the bolt handle retainer pin into place, or the bolt fell off a table somewhere along the way. From the picture it appears to be a cosmetic issue. Unless your bolt shows evidence of a crack going into the body of the bolt I would not worry about it.

? Where specifically is the missing chunk or gash?

I've seen several recoil pads (especially the early Limbsaver pads) that turned to goo at a certain point in their life. Reasons tossed around were bad rubber compound, reaction to the carpet glue used in some gun safes, and reaction to oil - but I've not yet seen a Benelli factory pad go soft. Maybe 15 years is the life span? I have a factory Comfortech pad on my personal M2 that is pushing 10 years old and still in good shape. All things considered 15 years is a good run - if the recoil pad gets a good bit of use. I'd probably good with the same type of pad and hope for another 15.

Drill/tap a blind hole about .250” deep. (Don't drill all the way through – that can weaken the attachment of the stud to the shell latch.)

Use good quality rings. With the heavier recoil from most “turkey” load you wan to make the sure the scope stays in place. Cheap rings “might” work OK, but if they let scope move at the wrong time you can bet it will be the shot right before you call in the best gobbler you've ever seen. Remarkable: I would be interested in know what the Benelli “maximum weight addition” formula is, and how the formula factors in the ammo's recoil impulse. Can you message more info?

What is the velocity (or Dram Eq.) and shot weight of the problematic ammo?

The rings need to be tall enough to position the scope's objective lens above the barrel or ventilated rib (scope not touch the barrel/rib). Without knowing your scope's objective size (32mm, 40mm, 50mm, etc) I can't give you a good answer. Maybe a local sporting goods store can show you a few examples to pick from and help with the decision. Also some scope manufactures have charts available recommending a ring height for their various scopes. If I had to make a guess...when using a scope with a 40mm objective “medium” rings will often work.

I'm not seeing one in stock at the usual sources. You can get on the back order list at Benelli