I have a Glenfield Marlin that will FTFeed every 5-6 rounds. I have cleaned it thoroughly. Failed round noses without feeding into chamber.

You have the two-piece feed throat? Those can get out of alignment.

Dunno?

I will check in to this.

Related pic.

Pretty sure I do have the two piece.

But it looks more like the feed arm? Isn't lifting the rounds high enough.

Cartridge lifter could be bent or out of shape. Has it been disassembled recently? Might want to check that everything is clean and lubricated.

I will check it out tonight

Give it a good detail cleaning

It may be a magazine issue. I have the same rifle and sometimes I've noticed you have to apply a bit of upward pressure to the magazine for the bolt to close smoothly.

I recently inherited a Glenfield model 60. I took it apart and cleaned it up really good. But it won’t cycle a single round. They all go nose up into the top of the chamber.

Rimfirecentral has some very good fixes on their site.

It might be the spring or the feed block.

Marlin tells you not to run Stingers.  My Glenfield ran really well on Stingers, but ate cheap optics.  Finally ended up w/ a scope that cost twice as much as the rifle, no more issues.

How does a rifle, a rimfire at that, "eat optics"?

1) Take a blowback rifle action.  Manufacturer puts out a specific warning that Stingers are not to be used - essentially, the bolt moves too fast for the buffer, so it hits the back of the receiver w/ more than normal force.
2) Place stock alongside head of your significant other.  Stock breaks.
3) Rife now in pawnshop.  Sell to backbencher for $20 w/ broken stock.
4) backbencher repairs stock.  He has $20 in rifle, proceeds to WalMart, buys a $12 plastic tube scope w/ plastic lenses.
5) backbencher proceeds to local gun range in a sad attempt to zero a $12 rifle optic w/ Stingers.  Crosshairs meander where they please every time the bolt smacks the rear of the receiver.  Scope goes back to WalMart.
6) backbencher invests 150% of the cost of the rifle in a $30 scope from a well-known LGS.  Returns to local range.  Gets new scope zeroed.
7) backbencher now happily plinking away w/ now zeroed $30 scope on $20 rifle.  Crosshairs fall off their mountings and rotate some 30 degrees or so.  Scope returned to LGS.
8) backbencher purchases a $40 optic from LGS, zeroes it, later moves it to his Ruger 10/22, then recently to his boy's left-eject AR-22.

Any recoil action an optic is not designed for can destroy an optic.  In really cheap .22 optics, excessive recoil from Stingers in a semi-auto not intended for em can break the optic.  FN SCAR-17s, w/ their large bolt carrier slamming home, are known to stress even decent optics.  Spring-piston airguns are infamous for destroying optics not intended for spring-piston airgun, as the rifle recoils forward rather than backwards.

Yeah, I knew about the spring-powered air guns being hell on scopes. But I'm still finding it hard to believe a rimfire round is enough to burn out an optic?

If it was enough to burn one out, it would seem to me that the recoil would be noticeable enough to the shooter to be aware of it? After all, who would want to beat to death the bolt on a favorite gun?

Mine loves the cheap CCI Blazers.  Took a while to find a 100% reliable ammo type but at least that ammo is cheap during non panic times.

I was just getting started shooting @ the time - my 1st .22 rimfire rifle.  I had read up on Stingers & they have the same ME from a rifle as .38 SPL does from a revolver.  That sounded good to me, and Stingers were cheap back in the 90's.  I didn't have the manual at the time (the WWW had just been invented), so if it fits, it shoots.