I recently acquired a custom AR-10 in 6.5 creed (my first AR-10) from a forum member in a trade and I am having some issues with it. If I lock the bolt back and try to drop the magazine, the bolt also closes. Also, if the bolt is locked back with no magazine in the rifle, I can slap the side of the receiver and the bolt will close.

Am I correct in assuming this should not be happening?

Sounds like your bolt catch is worn or the catch spring or detent is missing. Take the upper off and take a good look at the bolt catch. If it looks good, manually manipulate it and see if the spring is working correctly.

Yep, this exactly. I had one do this in an AR15 and it was the bolt catch spring was wore out.

It's very common for bolt catch to be worn. Almost all our issues M4s in the army would do the same thing.

I removed the catch, detent and spring. All parts were there and intact. Is there any way the spring is worn out enough to cause this problem?

Yes they can be worn down enough to not have enough force on the bolt catch.

Ok. I will have to find a new spring and see if that fixes it. A little frustrating though, I was assured by this forum member that he performed a function test with the rifle prior to shipping it. Clearly, he did not.

If you're going to get another spring might as well get the bolt catch at same time. They're cheap and if the other is wore a little it would be good to change them now.

My thoughts exactly. Should I just go with another stock bolt catch or are there any better options out there?

Seekins make a nice bolt catch and it slightly larger and easier to use.

Sweet. That'll do. Thanks Sapper.

Seekins makes some good stuff

I have a very different view of their stuff,their barrels SUCK !

Never tried a barrel before but their uppers and lowers and parts are nice

My AR-10 is the same way, breath on it and it drops the bolt. it also broke the bolt release once also

Just a caution that an AR15 bolt catch will NOT work in an AR10. Also, the DPMS AR10 and Armalight AR10 are different in design and are not interchangeable.

I think Aero Precision makes an enhanced DPMS style AR10 bolt catch.

I agree with what the others have said and would look at the bolt catch and spring first. Is the stock a full length A2 stock or does it have a carbine stock on it?

Big Fitz, it has a PRS stock on it. I did look at the catch and the spring and detent and all look to be in fine condition. I was reading on another forum about a similar issue and the guy discovered that the pad on the bolt catch was too thick and the upper pushed on it slightly when the upper and lower are assembled. I was looking at mine and it looks like it may be a similar issue.

My ar10's are touchy too. The mag catch and bolt catch on them usually need some work. You have to find a slightly larger catch.

MD, the PRS stock will have a full length A2 style buffer tube. An additional check to perform is to pull the buffer out and measure and make sure it is an AR10 length buffer and not an AR15 length buffer that has been installed. They look similar but the AR10 buffer is shorter to allow for the longer cycling stroke of a 308 sized case vs a 223. If an AR15 buffer is installed, it will compress the spring more than designed resulting in greater force of the BCG on the bolt stop.

I experienced the above in an AR10 I bought from a forum member on here and experienced the same issue. Replaced bolt stop and spring, no joy. Tried other BCGs, no joy. Finally decided to pull the buffer and spring and noticed the buffer was too long! I too was assured the rifle functioned flawlessly and never had a problem...

Big Fitz, that's another great suggestion. I'll have to check that as well. It is definitely frustrating to receive a non functioning firearm in a trade, especially when the firearm you traded functions perfectly.

Let us know how it works out.

same thing happened to me with the buffers - AR-15 Carbine buffer vs. AR-10 Carbine buffer