Another Grendel that won't extract a spent case. with Pictures. Help!

[LRRPF52]

Cycle the action using the charging handle about 200 or so times manually, with very little oil. This will break in the parts a little and make them function smoother. My Grendel shortstroked and had feeding problems the first 50 rounds. So, I cycled it several hundred times to smooth out the new parts. It help alot. Then, I ran it wet (lots of oil) for the first couple hundred rounds. Now, it works 100 percent. You have to break in AR's. All the parts are painted or coated with layers of rough (in comparison to smooth bare steel) coatings that rub against each other and cause friction. The coatings need to be smoothed out by a little wear before they slide more freely. Most of my first malfunctions with my Grendel were caused by needing break in and magazine issues.

I was having a similar problem with my first C-products magazines. The feed lips stuck too far up into the rifle and rubbed against the BCG and the square hole where the magazine catch grabs onto the magazines weren't cut right. Even after tweaking the lips they still wouldn't run right. I sent them back to C-products and they sent me new ones. I still had to tweak the lips, but they ran much better. Oh, the Alexander Arms mags are also C-products mags but with an AA bottom plate.

Ya just can't take a new out of the box AR to the range and expect it to function 100 percent right off the bat. without break in. You have to be a little patient with it at first. It's usually around the 250 - 300 round count before it smooths out completely and starts to run smooth.

I expect every AR I put together to function 100% from the start, and I'm usually successful achieving that unless introducing some new, unproven component. I polish the raceways on the bolt carrier to avoid the break-in with bolt carrier to upper friction, and using Slip2000. I also lube the recoil spring with Slip2000 to do the same thing with the anodizing inside the extension tube.

One thing that I would not want to do by cycling the action 200 times is wear out the recess for the charge handle latch on the upper. This is one design flaw of the charge handle that can cause the handle to come loose while you're shooting. A steel latch versus the aluminum upper will leave the steel latch the winner every time. You can forgo the 200 cycle break-in by polishing your BC raceways and using a thick, viscous lube. Some guys even polish the inside of the upper. A Milspec upper has a dry film lube baked into it after anodizing, which has a pretty rough finish as Mutt described, but serves as a good base for absorbing and retaining lubrication.

The last two AR builds I tested ran 100% in high-volume torture tests with M193 to the tune of 350 rounds per. If you have quality barrels with the corect gas port diameter, the correct bolt carrier weight, the correct recoil spring and buffer, decent mags, and the correct octane fuel, they will run.

I would advise against cycling steel on the dry film lube to smooth it out, since that is the porous base that will hold your lubrication better than worn and exposed aluminum.