Hey gang. I have an upper, bbl, bbl nut, gas tube, and gas block from Radical Firearms (16" 300 blk) to go along with a seekins rail system, fail zero BCG, and BCM gunfighter charging handle. This upper was brand new, and came unassembled so I could cerakote the upper/lower. I got the beast all together today and the charging handle is more difficult than normal (not a lot, just noticeable) to pull to to the rear, especially at the begining...and when I let it go (not babying it, really letting it fly) it seems to go about 95% of the way 'home' but I can still use the FA and get some forward movement out of it....more than on my other radical 300 blk (uses similar parts, it's just an 8.5" SBR). Is this a situation where I should just sit in front of the TV and charge the beast a few hundred times so that friction than loosen it up (phrasing!) or is there a bigger problem here? Not sure what the likely culprits are. Doesn't seem to be any cerakote in the channel the BCG rides in and the chamber/BCG are definitely clean so I don't think it's a coating issue. If I take the upper off the lower and just slide the BCG in by hand, it slides freely until the bolt starts to engage the teeth of the extension. Naturally, there should be more resistance there because the bolt has to turn etc. but this seems like more than normal.

Thoughts? Is this what all ARs feel like when brand new and it just needs some break-in? It's not my first AR...but it's been awhile since I built one so my memory is fuzzy regarding how easily the BCG moved prior to firing...

Shoot the damn thing and let the parts wear into each other, then decide if you have problems.  There are like 3 different threads in 3 different sections going on about this very issue right now, you guys need to shoot, or cycle a little bit of time to make sure everything is set right and has had a small amount of time to get to know each other!

This.

Dip the whole BCG in some clean motor oil and shoot a mag through it of full power ammo. If she has problems after that, come back and let us know.

It should close without issue TBH - if not something isn't right.  The 'shoot it in' crowd has a point to an extent but you don't want hard stops before you try to chamber your first round.

Check the bottom of the end of the charging handle (the part you grab) and see if it isn't bottoming out on the top of the upper OR the top of the receiver extension ring on the lower.  My Aero Precision upper and one of the charging handles I tried did precisely this.  Swapped to another brand (Gunfighter) charging handle and no problems.

Make sure your bolt is moving freely in your carrier. It will be tight, but you should be able to work it back and forth by hand. Make sure your charging handle is riding freely in the upper. Place it in there and make sure it goes all the way forward before you put your bcg in. If all of that checks fine then you may have an issue with your bolt or barrel extension. Then its time to take the barrel off and do some measuring.

The bolt is bone dry, I'll try a tiny bit of lube there and a bunch of manual cycling to see how that feels. Could also try swapping parts around to see if I can't narrow things down a bit too. Thanks for the tips guys. I suppose I should have googled this... Apparently lots of people have experienced "stiff bolts" with brand new FZ BCGs...

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OP not a little bit of lube, a lot of lube, that thing should be soaking wet. In a brand new rifle you want a lot of lube until the parts get broken in then you can back it off some.

Listen to others advice, lil lube, no..LOTSA lube, and dont baby it.
Its a frigging AR, not a English double rifle.

Call me an idiot if you see fit but I don't understand why people say soak your gun in lube to break it in. Lubricants are suppose to reduce friction and minimize wear. You want to wear (break) the parts in so they move smoothly. I gotta think your better off racking the charging handle a bunch or shooting with little to no lube at first.

I for one hardly use lube at all on my rifles and when I was still in the army I would give my rifle a nice light coat of clp when cleaning it but never soaked it. Only exception was when firing blanks but even then not to the point that some guys on here are always suggesting.

To each their own I guess.

Make sure gas tube is correctly aligned to the carrier key.

Take upper only without charging handle pointed straight down and slowly lower the bcg into the receiver. Is should lock into battery smoothly.  Gas tube should not look like it has any pressure on it either.

Make sure the bolt closes on empty case or snap cap as well.

This will also let you know if it is a CH issue or not.

It's much more likely that you'll have a failure due to your AR being under lubricated, than over. So most just say to soak it, as it can't really hurt anything.

Oh absolutely I won't disagree with that statement. But the idea that it will actually assist in breaking in parts isn't that accurate. How ever it will allow parts to move easier which probably is a safer way of doing it. But for a charging handle... I wouldn't worry about soaking it, just rack a bunch

Ok your an idiot.



Do you break your new car engine in without oil? The point is the oil allows proper mating of the moving parts instead of scoring the surfaces which would occur if it is dry.

The oil acts to "hone" the surfaces especially when you have hardened steel riding on aluminum.



 

If your pulling the charging handle all the way back and letting it go, and its NOT closing, somethings NOT right, and oils NOT going to fix it.

Its hitting the gas tube, locking lugs or something.

Did you shear the index pin on the barrel extention and your locking lugs are not lining up?

I have a FZ bcg in both my uppers and have no issues, other than I should have picked up more at $99

I'd second this.

Both mine were super stiff right where the bolt rotates in/out of battery.

I cycled them by hand a bunch dry, like 200+ times, before cleaning lubing and first firing.  No troubles except the 300blk needs a little more break in maybe.  Three out of four factory loads I've tried short cycle the bcg.  

Both mine were super stiff right where the bolt rotates in/out of battery.

I cycled them by hand a bunch dry, like 200+ times, before cleaning lubing and first firing.  No troubles except the 300blk needs a little more break in maybe.  Three out of four factory loads I've tried short cycle the bcg.  

Breaking-in does contribute to smooth movement of the bolt carrier.  Until that broken-in point is reached anything you can do to help the BCG keep going is a good idea.  Also - during break in you'll be exposing new metal; that's what break in is.  That new metal won't have lube on it when it's exposed so a little extra banging around in the upper helps keep you covered.

I've manually cycled it probably 200-ish times now, with a decent amount of CLP. It's definitely getting better. Now when I let it soak home, it does go ask the way into battery and the bcg doesn't really move forward when I tap the FA, so I think it's good to go. I'll knock out another couple hundred cycles, then clean it a bit too get rid of excess lube, then try some live fire. I think it'll be good...

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Good luck, don't forget to update us as to how it worked out.

What he said.