AR 10 Bolt Catch won't catch BCG?

[ApexerER]

Hello everyone, other than my introduction this is my first thread. Found this forum searching for an answer to this problem.

I built an AR10. This is my first build and it is basically the cheapest stuff I could find. I didn't want to bugger up a bunch of expensive parts trying to figure out what to do.

Anyway, the bolt catch won't catch the bolt. With or without a magazine. I filed the back of the bolt catch so that it could travel further. That didn't help. I wondered if I received an AR 15 Bolt catch with the lower parts kit so I pulled the one out of my 15 and they are different. This is my first build and I really don't know what else to check. It seems to operate correctly. Any idea's?

 

[ApexerER]

Here is a pic of both my evil rifles.

 

[Robin]

I have read about certain instances where trimming about an 1/8" off that soft material on the buffer will allow the bolt to travel just far enough to catch. Worth a try, and costs nothing.
Robin

 

[Vapor]

I had this happen on my friend's ar10. I had to remove some material with a belt sander. Is this where you've already tried?

 

[ApexerER]

I had this happen on my friend's ar10. I had to remove some material with a belt sander. Is this where you've already tried? View attachment 72854

Thanks, yes that is exactly where I removed material from. It didn't make any difference.

 

[Vapor]

If you take the upper off and put an empty mag in the lower, does it appear to actuate it?

 

[ApexerER]

If you take the upper off and put an empty mag in the lower, does it appear to actuate it?

I don't know....i will check. Thanks for the tip

 

[ApexerER]

If you take the upper off and put an empty mag in the lower, does it appear to actuate it?

Yes it does, just tried it to make sure. While I had the upper off I removed the BCG and tried sliding it across the lower and into the buffer tube. It seems the BCG will not go into the buffer tube to allow the bolt catch too operate. Can I cut a 1/4 inch off the buffer?

 

[ApexerER]

I have read about certain instances where trimming about an 1/8" off that soft material on the buffer will allow the bolt to travel just far enough to catch. Worth a try, and costs nothing.
Robin

I think this is what I have too do. I took the upper off again and removed the BCG. I slid that against the lower and into the buffer tube. The BCG won't go into the buffer tube far enough to let the bolt catch engage.

 

[Twogunwilly]

Change mags, I had the same problem with my msr10.

 

[GOYABEAN]

Hasn't there been issues with certain AR10 uppers not matching with certain lowers different manufacturers

 

[dwa12479]

Are all your parts a matching pattern? The AR10 is not standardized like the AR15. There's a DPMS pattern and an Armalite pattern. Many of the parts and magazines are not compatible with each other.

 

[GUNSICK]

I had this happen once and it ended up being the buffer tube was out of spec. It wasn’t deep enough to let the bolt go back enough. I compared it to another one and it was way off. It wasn’t the outer length but the inner like they didn’t machine it deep enough.

 

[Vapor]

Yes, are your upper and lower the same maker?

Dpms
Palmetto
Armlite
Anderson

They can all be different spec. This is one of the reasons I've stayed away from the ar10 platform.

My friends palmetto required some fitting even becuse the upper and lower were different generations.

 

[dsdmmat]

Here is a pic of both my evil rifles.

You need to get the right buffer. Don’t cut it down.

 

[ApexerER]

Everything is supposed to be DPMS platform on a DPMS lower. I did alot of research on that before buying parts. What I don't know, if it is anything like auto parts, what you order and what you get can be two different things. Problem is I can't just look at the part and know whether or not it is correct.

 

[Vapor]

If you can, maybe take more photos for us? Heck, maybe even a video? We want to help, it's just hard over text.


Do you have any friends with another ar10 upper?


You may need to play with buffers, tubes, or even a different bcg.

 

[dsdmmat]

Everything is supposed to be DPMS platform on a DPMS lower. I did alot of research on that before buying parts. What I don't know, if it is anything like auto parts, what you order and what you get can be two different things. Problem is I can't just look at the part and know whether or not it is correct.

DPMS 308 buffer is shorter than the AR15 buffer by about 3/4 of an inch (Both the carbine buffer and the rifle buffers)

 

[ApexerER]

If you can, maybe take more photos for us? Heck, maybe even a video? We want to help, it's just hard over text.


Do you have any friends with another ar10 upper?


You may need to play with buffers, tubes, or even a different bcg.

I don't know anyone with a 10. I can take all the pics you would like..what should I post pics of? Buffer and spring? Buffer tube with a tape measure? Lmk what to post and I'll do it this afternoon. Turkey hunting right now! Wish me luck!

 

[Eddie Gunks]

Yes it does, just tried it to make sure. While I had the upper off I removed the BCG and tried sliding it across the lower and into the buffer tube. It seems the BCG will not go into the buffer tube to allow the bolt catch too operate. Can I cut a 1/4 inch off the buffer? View attachment 72877

do you have a 308 buffer? They are different than the ar15. (They are shorter). Buy the correct parts.

That being said. If it locks back with the mag in it, it should lock back manually as well. Really.

 

[ApexerER]

Thanks everyone. I spoke to the business that I bought the buffer and spring from. He said to cut he sent me the wrong spring and is sending me a new one. In the meantime he said I can cut a coil off it but I think I am just going to wait for the correct spring.