Buffer spring is getting stuck in buffer tube.

[Birindj]

I have a bit of an issue. I recently finished my build and took it out to the range and put 200 rounds through it without a problem. I went out again on Sunday and after about the fifth round my bolt got stuck partially in the buffer tube. I unloaded the rifle and made sure if was clear then I smacked it on the stock and the spring came loose pushing the bolt forward. I tried to take a few more shots but the spring kept getting stuck. I took it home and took it apart, inspected the buffer tube, checked the spring, and everything looked fine. put it back together and pulled the charging handle several times and was fine. I'm just not sure what would cause this, and I don't want it to happen again the next time I go to the range. Anyone have any ideas as to why this would happen and how to correct it?

Thanks

[SB1964]

Pics would make it a lot easier to help. Could be anything from the buffer stop sticking up to a really light spring. The tube might not be into the buffer tower per spec. It could be a crappy tube catching the spring. Likely not the stop, scratch that.

When you open the pivot (rear) pin & slowly close the upper & lower, does the BCG press on the buffer?

Cycling the action by hand & the forces created when shooting it are worlds apart...

[Merc1138]

Can you take a picture of your rifle... like this?

[Birindj]

I will post pics as soon as I get home.

[Wallabing]

Make sure your buffer tube notched is centered and aligned with the buffer retainer.

Your buffer retainer could be dragging/catching on the rear end of your bolt.

[SinCal559]

Spring on backwards?
Aluminum burr in tube?
Out of spec tube or buffer?

[kcstott]

Spring on backwards?
Aluminum burr in tube?
Out of spec tube or buffer?

Spring on backwards??? really?? since when did they put a "front toward enemy on the buffer spring??

[AreWeFree]

Spring on backwards?
Aluminum burr in tube?
Out of spec tube or buffer?

That's easy to tell, it'll sound like GNIORPS instead of SPROING.

[Birindj]

The buffer tube came with the Magpul UBR stock.

[AreWeFree]

That's a rifle length spring, doesn't the UBR use a carbine spring?

[Braddah Jay]

Stick the buffer in without the spring and run it back and forth to see where it's hanging up. It could be slightly bent or debris in the tube?

[Birindj]

I'm not sure about the spring, i got it from a friend and its 12.5 inches.

[Merc1138]

I'm not sure about the spring, i got it from a friend and its 12.5 inches.

That's a rifle length spring then. You need a carbine length spring, and I don't think you can simply trim them since the spring rates could be different. Fortunately, it's a cheap fix.

[AreWeFree]

Where are you located? I'll give you a carbine spring if you want.

Edit: Here are a few links for carbine springs:

http://www.midwayusa.com/product/210662/dpms-buffer-spring-ar-15-carbine

http://damageindustriesllc.com/product/spring-recoil-buffer-carbine-ar15m16

http://damageindustriesllc.com/product/enhanced-spring-recoil-buffer-action-carbine

[Birindj]

Thanks for all the help guys. Last two questions.
1) Would the spring be the cause or could it be something else?
2) could there be any damage to the BCG or upper caused by the larger spring?