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Failure to Feed After Modifications - Lifter Not Lifting Shells


m4prime

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Hello everyone. Pretty bummed out right now. 

Bought a Benelli M4 a few months ago. Have shot about 200 rounds of full power stuff through it and have absolutely thoroughly enjoyed it. 

When I bought it, I knew I was going to 922R extend it to the full 7 round tube, along with some other modifications. 

 

I did those modifications today, with pretty disastrous results. 

Modifications: 

- Freedom Fighter Tactical (FFT) Titanium 7 Round Tube

- FFT aluminum follower 

-FFT Wolf extended spring 

-FFT Worry Free Lifter

-FFT Oversized Bolt Release 

-Midwest Industries Grip (not installed yet because the gun is not functioning right, and it complicates disassembly) 

 

Didn't have any issues with the tube. Just heated, twisted off, no problem. Screwed the new one on as tight as I possibly could while mounted on a vice, inserted follower, spring, and retaining piece. 

 

The lifter was a similar story. Just watched a YouTube video and removed the trigger assembly, and followed the instructions and installed the lifter. I did run into a small issue here, the lifter had such tight tolerance, it would not go back down under spring tension. The OEM one did. I gently filed down the plastic on the trigger control group around the section where the lifter was catching, and it then functioned as it should. Lift up, drop back down under spring tension. 

 

The bolt release was a bit more tricky, and I strongly believe this is where my issue lies. I followed a video for this one as well. All seemed well, other than the bolt release being dramatically more stiff than the stock bolt release button, despite being so much bigger and giving me so much more leverage. 

 

While the gun was disassembled, I took apart the bolt and cleaned it with CLP, and lubed it with my usual Slip 2000 oil. 

 

Problem:

So, gun is fully reassembled. I start with snap caps. Immediately notice an issue. I start loading to full capacity (7 + 1 in the chamber). I click the shell release, and the shell dumps onto the lifter. I dump the round in the chamber by pulling the bolt back, and the next shell did not lift fully up into position. 

It would lift perhaps half way. On occasion I could get it to lift on it's own, but I'd say that was 1/10 times. 

 

I went to the nearby range and discussed it with the guy there who I know is the shotgun guy at the range. He immediately pointed out my bolt release, and agreed it was incredibly stiff and something felt very wrong. We punched it out, and reinstalled it. It felt better, but still stiff for sure. 

 

I loaded it up with 00 buck, and fired one round. Extraction was fine, but the lifter once again did not put the next shell into place. A small tap from the bottom of the lifter immediately shoves the shell into position and the bolt flies forward and puts the shell into the chamber. I took a few shots, and knew it was pointless, so dumped the tube out and packed up. 

 

Troubleshooting

I figured the correct thing to do was just to work backwards and uninstall parts one at a time to find the issue. 

I started with the lifter. Swapped back to OEM. Zero change. 

Then the bolt release. Zero change. What I did notice was that the bolt release was notably at an angle when the bolt was locked back, and INCREDIBLY hard to press. This is why I think my issue is coming from something I did during the install of the bolt release. 

Went back to the stock tube and stock follower and stock spring, zero changes. 

I realize that the filing I did to the trigger group plastic may be a cause, and is the only one that I can't eliminate for sure, because I don't have a brand new one to throw in to confirm it's an issue (like I did with all the other parts, by swapping back to stock).

However, from my reading, the bolt release is integral to the loading action, and so my issues with the bolt release being super super stiff, that is where I have been leaning towards. 

The last (and most terrifying) possibility is that I somehow damaged the receiver, either by overtightening the vice I set it in, heating, twisting on the tube, etc. No idea how to check or test this. 

 

Any suggestions are absolutely welcome. I'd like to try to fix this myself before I take it to a gunsmith. It really was a downer because I spent all day working on these parts that I spent a month saving up to purchase, only to end up with an unfunctional gun (likely user install error, and not the gun nor the parts themselves).

 

Any other troubleshooting tests, photos, etc that anyone would like, please ask and I will do it. 

 

Thank you all in advance. 

Edited by m4prime
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Update:

Well guys, I think I have solved my problem. 

 

The video I watched showed the shell stop spring being looped around the tab on the shell stop plate. 

I found the install guide by StrangerDanger and saw that the spring is simply placed on the plate. 

I tore down my M4 again (for the probably 12th time today) and put the spring as per the write up. 

Immediately I noticed the bolt release was so much lighter. 

I loaded the tube up with snap caps, and cycled through the whole tube. Tried not to get too excited as they were heavy snap caps, so loaded it fully with 00 buck shells. 

Cycled through the whole tube 4 times. Had one shell on one full tube cycle fail to load, but I'm going to chalk that up to hand cycling and not being forceful enough. 

Off to the range tomorrow to test it with the piston system doing the cycling work. 

If I have any issues I think it will just be further adjustment of the shell stop plate and spring. 

 

I'm just really relieved I didn't do something really dumb like irreversibly damage the receiver in the vice.

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Thanks for sharing your experience. Hopefully as you say, you have solved the issue. In any case thru this you have gained intimate knowledge of the operating system and how the parts interact and rely on each other to an extent, for flawless operation of the gun.

You probably heard all this before but, a couple points....

One also should remember that many times aftermarket parts do not immediately "fit" because there may be a thousandth more here or a thousandth less there when made, that requires some fitting or in some cases, just plain won't work.

It's been recommended that one mod be done at a time, test ok, then do another so it takes the guesswork out of what's causing a malfunction.

Post back after you fire it to let us know.👍🙂

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37 minutes ago, Evolution said:

Thanks for sharing your experience. Hopefully as you say, you have solved the issue. In any case thru this you have gained intimate knowledge of the operating system and how the parts interact and rely on each other to an extent, for flawless operation of the gun.

You probably heard all this before but, a couple points....

One also should remember that many times aftermarket parts do not immediately "fit" because there may be a thousandth more here or a thousandth less there when made, that requires some fitting or in some cases, just plain won't work.

It's been recommended that one mod be done at a time, test ok, then do another so it takes the guesswork out of what's causing a malfunction.

Post back after you fire it to let us know.👍🙂

Thank you for your reply. 
 

I definitely learned a few lessons. For one, I can now field strip a Benelli M4 half asleep in 2 minutes. 
 

My hands hurt. 
 

My receiver has scratches on the finish. 
 

All sound like net positives to me 🙂 

 

And absolutely I agree, yes… one mod at a time. Had I done one at a time, I would have been easily able to pin down what caused the issue. It would have been as simple as assembly after each modification, and then cycling through some snap caps. 
 

Heading to the range shortly, will update. Bringing 3 different types of full load 00 buck, with enough to cycle at least one full tube of each, with another set of each to do a full tube + 2 ghost load. Will keep track of any malfunctions. 
 

Have a dripping soaked bolt, rails, and bolt carrier group.

 

Wish me luck! 
 

Question for you… is it normal to have a small gap between the bolt and the breech? I swear my bolt carrier group used to block the view completely and all I could see was black when the bolt was forward, but I could be wrong. I’ve seen a mix of both on google image searches. 
 

IMG_4597.thumb.jpeg.e08676cc2ea7111f7246339b96c604d4.jpegIMG_4596.thumb.jpeg.fbdcd652d1c4f6d4ee74ab649906b59b.jpeg

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My experience is that the FFT shell lifter is garbage.  If I would slowly move it I could get it stuck.  I had many issues and tried to fix it a couple times where I got it to move like it should but eventually went back to rubbing.  Put your oem lifter back on and see if it solves the problem.

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Woohoo! 

Range day was a success. 

Went through 50 shells without a single malfunction. 

Ran all full power 00 buckshot. Ran through as many different brands as I could, and different conditions. Mixing brands into the tube, fast firing, slow firing, full tube, single shell in the tube, etc. Federal, Remington, Winchester... everything load and every test performed flawlessly. 

Edited by m4prime
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