AR cycling issues...

View · by **BlkVooDoo** on Sat Feb 16, 2013 6:00 pm

So, I recently finished my first AR build. Thursday I did the initial testing and I was getting a situation where the spent brass would stay in the chamber. The bolt would slide back and push a new round into the back of the spent brass. So, after doing some research and talking to a few people I cleaned the chamber area, and put an o-ring on the extractor spring.

I reassembled everything, and I am now getting a situation where the firing pin is hitting the primer ever so softly.

Is there something I am missing here? Is this normal, because I would not think so?

If it is normal, then I will chalk it up to learning something. If it is not normal, what do I do?

Rifle is a Kies upper, Kies BCG, Kies lower

View · by **catalyst686** on Sat Feb 16, 2013 6:23 pm

Sounds like a possible BCG issue to me, is the gun unfired? If the bcg is used there could be carbon build up that is not allowing the firing pin to strike properly. You could also be having light hammer strikes. Is the lower new? Did you assemble the lower or is it from the factory? If you assembled it, what kind of LPK did you use? Have you been doing function checks with just casings? If you have been, try using snap caps, the round will not feed into the chamber in the fashion is was meant to if it is just the casing and not an actual round. If you're having light primer strikes, failure to feeds, along with failure to extract, I would suggest that it's primarily an issue with the BCG.

View · by **BlkVooDoo** on Sat Feb 16, 2013 6:29 pm

catalyst686 wrote:Sounds like a possible BCG issue to me, is the gun unfired? If the bcg is used there could be carbon build up that is not allowing the firing pin to strike properly. You could also be having light hammer strikes. Is the lower new? Did you assemble the lower or is it from the factory? If you assembled it, what kind of LPK did you use?

I assembled everything except the upper and BCG. Which the owner of Kies assembled. It is a Spike's LPK.

It is brand new. Everything is brand new. I fired maybe 15 rounds through on Thursday. It has not misfired yet, but I did not notice this before putting the o-ring on the extractor spring.

The hammer has not touched the firing pin since Thursday. This is a new issue, that just started 30 minutes ago.

I should note, this is happening just by cycling rounds through. NOT FIRING THE RIFLE.

View · by **Rip Van Winkle** on Sat Feb 16, 2013 6:32 pm

Looks like the bolt isn't going completely into battery. Maybe the new spring/O ring isn't letting the extractor go over the cartridge rim?

View · by **catalyst686** on Sat Feb 16, 2013 6:38 pm

Rip Van Winkle wrote:Looks like the bolt isn't going completely into battery. Maybe the new spring/O ring isn't letting the extractor go over the cartridge rim?

Yea, I'd take the O ring out, can we get a few pics of the BCG?

View · by **BlkVooDoo** on Sat Feb 16, 2013 6:38 pm

Rip Van Winkle wrote:Looks like the bolt isn't going completely into battery. Maybe the new spring/O ring isn't letting the extractor go over the cartridge rim?

Wouldn't put it further away from the firing pin then? Keeping the primer surface away from the bolt face?

View · by **wildfan1** on Sat Feb 16, 2013 6:39 pm

Is the gun properly Lubed? I had similar issues with my DPMS bull 24 when new. It was way too dry. I was running over 50% ftf or fte on first mag. Cleaned and oiled the crap out of it, not a single misfire since

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View · by **Shawski** on Sat Feb 16, 2013 6:40 pm

If that is happening just from loading a round into the chamber, it's normal. ARs have a floating firing pin. Hence why hard primers are used in 5.56mm ammo.

View · by **BlkVooDoo** on Sat Feb 16, 2013 6:46 pm

catalyst686 wrote:
Rip Van Winkle wrote:Looks like the bolt isn't going completely into battery. Maybe the new spring/O ring isn't letting the extractor go over the cartridge rim?

Yea, I'd take the O ring out, can we get a few pics of the BCG?

Yeah, best I can do with my cell phone right now.
Thanks guys!

View · by **catalyst686** on Sat Feb 16, 2013 6:49 pm

Lube that BCG generously!!! Maybe it's just the pictures but that thing looks bone dry my friend. Regarding your first picture, are the strikes on the primer from actually dry firing the gun when the brass is in the chamber? Or is it just from racking a round into the chamber. If it's just from racking a round into the chamber, that's totally normal for an AR.

View · by **BlkVooDoo** on Sat Feb 16, 2013 6:50 pm

catalyst686 wrote:Lube that BCG generously!!! Maybe it's just the pictures but that thing looks bone dry my friend.

Yeah, the exterior is dry right now. I wiped it clean to kill reflection from the flash. There is Hoppe's lubricating oil liberally placed on the firing pin and bolt.

View · by **BlkVooDoo** on Sat Feb 16, 2013 6:52 pm

catalyst686 wrote:Lube that BCG generously!!! Maybe it's just the pictures but that thing looks bone dry my friend. Regarding your first picture, are the strikes on the primer from actually dry firing the gun when the brass is in the chamber? Or is it just from racking a round into the chamber. If it's just from racking a round into the chamber, that's totally normal for an AR.

No, just from cycling the bolt with the charging handle. And if this is normal, than whew....

Thank you everyone!!!

View · by **catalyst686** on Sat Feb 16, 2013 6:55 pm

yep, that's 100% normal with an AR, glad it wasn't something to worry about!

View · by **jshuberg** on Sat Feb 16, 2013 7:01 pm

Double check that the legs of the hammer spring are on top of the trigger pin, not underneath it. This would result in light primer strikes.

View · by **Hmac** on Sat Feb 16, 2013 7:23 pm

jshuberg wrote:Double check that the legs of the hammer spring are on top of the trigger pin, not underneath it. This would result in light primer strikes.

This. Although I agree that if those marks are just from hand-cycling, it's normal because of the AR's floating firing pin.

As to lube, a quality AR built from quality components does like lubrication, but lack of it on a non-crudded-up firearm is unlikely to cause failures to extract in an otherwise clean chamber. Some brands of barrels are known for a higher-than-expected percentage of chambers that are too tight.