Unobtanium

I'm interested, as well. I would like to see some credentials/work/etc. as well. If your work is as solid as it sounds, and your turn-around time is within a couple of weeks, you're going to be a very popular guy (or girl, let's not be sexist, maybe some super hot girl is doing work on barrels and stocks, some of my past gunsmiths have been bombshell hot blondes, sooo...pictures of you, too, if this is the case!).

How well does the curvature of the FFT rail match the OEM when it comes to properly mating with the receiver?

I've owned 5. None needed anything but ammo. I was firing 2.75 dram 1145fps target loads out of several of mine on round 1.

Ask for a failure analysis. Call and ask for it. Very curious.

Oh, I agree, but when he gets it back and it still does it, if that is the case, then he will have no choice but to try other things and dump the budget ammo. I personally think it's the ammo, or a grotesque issue with the M4. There is no way full-power buckshot should have issues. My 2 dealings with benelli CS were this: I asked, and they sent me an FP retaining pin with O-ring since Brownells didn't sell them at the time. I wanted a spare and told them so. Done. #2, was I had an M4 with a SLIGHTLY canted front-sight. Barrel assembly was replaced within the same 3 weeks OP mentions. It was perfect, then.

Cheap enough to be worth the gamble and sometimes they come through.

Benelli doesn't screw around. They verify and then replace subassemblies. If the weapon has a legit issue, it will be fixed.

PiP suggestion: flatwire 17-7 spring. This will offer more consistent tension through the springs distance of travel and have a significantly shorter solid height for compatibility with any 2.75" shells and 7 round capacity. 17-7 offers excellent spring properties and effective corrosion resistance. Since nothing is in the ID of the spring, flatwire could be made very thin as material can be displaced to the inside without contact with moving parts. Further, spring resonance will be reduced and stability enhanced. Spring life will be significantly increased. "Last shot" spring tension can be higher with flatwire design without increasing last round loaded tension. A flatwire spring made of 17-7 would be optimal for this application, keeping feeding tension on rounds more consistent, allowing easier loading of last rounds, increasing spring life greatly, and offering higher corrosion resistance. A flatwire spring could be produced that would retrofit across the spectrum of shotguns in 12ga with 6-9 round capacity and be sold to 870, 590, FN slp, Beretta 1301, versa max, and other customers, defraying production cost via bulk order and sales. The main allure would be to the tactical and competition crowd as it would offer higher capacity on the longer 2.75 inch shells as well as reduced loading effort without any sacrifice of reliability. Who ever does this...send me half a dozen as a thank - you for my suggestion and we can call it close enough to even

The bathroom scale is a very poor tool of measurement for this next, but my MK1 palm agrees with the scale. The CC spring applied much more tension. I used a full-length FFT magazine-tube, with an FFT follower and Federal TruBall DP 2.75" slug shell simulating the "last shot in the magazine". The follower and slug were oriented operationally, and my hand functioned as a magazine-retaining spring/cap. I attempted to "settle" the needle on the scale as accurately as possible. The difference in percentage of force shown is about how it "felt" to my hand, which the CC spring created a much more enduring mark on. FFT spring "last round tension": 4# CC spring "last round tension": 5.5# Difference 1.5#, or roughly 25%. Again, this was a very poor tool for the job, but the difference felt by hand is easily 25%.

I am comparing the Carrier Comp and FFT magazine-tube package. This first section will focus on the lesser, but arguably trickier component...the spring. The magazine spring is very important to the operation of the M4 Benelli, as you may well know. However, it's a bit more finicky than most realize. It mustn't just push a shell out onto the carrier...it must do it QUICKLY and with authority. If you are firing heavy loads, such as 12-pellet 2.75" shells, or are firing 3" slugs, etc. the weapon will recoil briskly. When only 1 shell is in the magazine, this recoil tends to cause the non-fixed mounted shell to compress the magazine spring during recoil, attempting to remain at rest in the magazine tube, while the M4 recoils "around it". If the magazine spring permits this, a failure to feed malfunction will occur. Yet, if the spring is made of too many coils, it will limit the loading of 7 rounds to 6. Herein lies the trick...getting a strong spring of the correct length. Both FFT and Carrier Comp source their springs from Wolff, so I feel it safe to presume that both springs are of the same quality material and construction. However, they differ greatly, as we are about to find out. Static length. The FFT spring is 29.25" in length, while the Carrier Comp spring is 33": Wire diameter. The FFT spring is 0.039" in diameter, while the CC spring is 0.041". Solid height. The FFT spring consists of 48 coils, and the CC spring, 49 coils. The theoretical solid-height of the FFT spring is 1.872", assuming all coils stack directly upon each other. That of the CC spring, is 2.009". A capacity difference of 0.137", or roughly the thickness of 2 quarters stacked atop each other. Neither spring uses a "beehive" profile which would allow stacking without adding to solid-height. I do not feel that 0.137" difference in height is important, but with some brands of shells, it could indeed be a make/break proposition. If your favorite brand ALMOST makes it with the CC spring, it is likely to work with the FFT spring, however, there are functional trade-offs, as you will see in the next post.

Did you not try any of the other suggestions in the thread first? It would be a shame to lose your shotgun for 3 weeks because you got some out of spec ammo. I've had that happen with an M4, before. Wolf .223. Cases were out of spec. Wouldn't work in a Colt, Sabre, or anything else.

Even if you liked the modifications, the workmanship is visibly crap.

I'm no worse off than before the experiment. No stress!

Well, I got Botach'ed. They are telling me the stock is on back-order, so I told them that if that e-mail is correct, to cancel everything I ordered from them, and then called them. I spoke with the same girl I spoke with earlier this week who told me that yes, my order WOULD be filled. She made a show of trying to transfer me to CS, and when it went to voice-mail, she said "CS has already left". Well, they are in CA, and it was 1630hrs here in Louisiana when I called, which means it was 1430hrs there, so I sure hope they don't pay them for an 8 hour day in the CS department. Anyway, waiting to hear back from them as to whether they have cancelled my entire order as requested, or if there was a mistake in their last E-mail and they are shipping all of it. It's been a fun experiment! The result so far? Pass on Botach. They still suck.

The thread I was referencing was deleted. I found a link to it and was given "404" error. The consensus seems to be that it was a very small issue, though, from what I recall.

When the USMC changes over to the H20 coating, I'll embrace it. I still remember the BCG PiP project for the M4 carbine (5.56) that was cancelled months early because the old mil-spec phosphate BCG outperformed all the other whiz-bang offerings, special coatings and all. Hydrogen embrittlement is indeed a possibility, I believe, as well as tolerance stacking and other quirks. Remember the function-issues from 2012? I recall a few posts directly linked to the coating.

Why? The NP3 caused tolerance issues, and rust has never been a problem on a properly maintained M4, and you can "build" an H2O feature equipped model legally for about the same MSRP as the H2O, minus the problematic coating.

I guess if you're into collecting, sure. Anything can be worth anything, then.

Great short vid, skip to 34:00 if the M4 is all you care about. Please note...the semi-auto cycling of beanbag rounds...

You know what to do...

A few broken eggs in every omelet. The door is open, now, isn't it?

Yes, it's becoming increasingly popular that criminals will stealth their way into a home and reverse all of the door-knobs so that the locking mechanisms are all facing the other side of the door. This allows them to trap the home-owner in their home near their firearms.

Please try another load. Even field loads of birdshot. I feel like fiocchi is the issue if the weapon is well lubed and in spec.

I'd go with fireclean. I'm not a huge fan of dry firearm lubrication.

It's a steep price if he hand delivered it with a private bill of sale and no paperwork.