View Full Version : AR-15 Build/Bolt Catch Dent&Spring Fit?

March 21, 2010, 07:59 AM
I have a Stag Lower starting putting my AR parts on and the Dent or what ever they call it will not fit. I spent so much time even had the wife and son pushing on it in, no luck.

This morning with a new look found it will not allow the holes to line up, for the roll pin! (JUST A HAIR OFF ) it is like the shaft is to long?

I have the DPMS parts kit, postive using correct spring, the hole is clear and when all parts or in and spring compressed it is a hair off, just will not go in place. I have the small punch as a slave it will not fit. I did remove the dent and with the spring it will fit using the punch as a slave.

I was thinking of trimming the shaft that goes in the spring, it looks like if I remove 1/3 it would work. It just gets stuck and the holes are off by a true "hair"

March 21, 2010, 08:27 AM

Positive you have the right parts? Its a real PITA to get aligned but you shouldn't have to cut anything...double check and get back to me :P


Also, don't mar the receiver when you drift the pin in.

March 21, 2010, 08:49 AM
I have the parts, no question have checked several times. I did go into a box of spare parts and found a spring that was shorter but the same.

I just went down and have the slave through with the spring and dent in place. How far must the bolt catch lift it goes up about a 1/4 " but all fits and works. The receiver is an old one this is a spare parts gun but have all the stuff and tools.

Thanks for the help what do you think about the shorter spring?

I have to go see the preacher with the wife and when I get back will start back on this.

I could have gotten some paint in the hole used a good engine block paint, it worked great if the parts are warm then hit it with some heat it makes a good finish. The hole seems clear have dug around in the hole, it seems clear?

March 21, 2010, 09:24 AM
WHat are you talking about the ... "Dent"? Which Detent are you talking about? Is it the detent SPRING or the Detent itself. Or are you talking about a Roll Pin?

Here is a failsafe video series on building a lower .... http://www.youtube.com/watch?v=iA_Vkb2UB1w

I have found that if you have problems placing a roll pin in place you can use a small needle file to scrape out the paint inside the hole. This will make it go in easier, and it will also hold it snug enough as long as you don't file out too much. It's supposed to be stubborn to get in. If it weren't it would fall out when you fire it.

I also use a small tac hammer when assembling these, because it's small enough to get into tight places and doesn't have a bulky head.

March 21, 2010, 12:30 PM
Ok, thanks for the help and glad to report problem solved and lower is done, touch up paint applied. I started this project many years ago and had problems with the lower so did build the upper.

I started over and have plenty of parts and the tools so off I went, the problem was solved after removing my head from my A**!

The last time I used the trigger spring and it was still stuck in place, which is why the spring and dent would not go in place. I used a paper clip bent it like a fish hook, bang pulled it out.

So back at it if something comes up will ask you for help again, thanks

March 21, 2010, 12:43 PM
Sweet good stuff : )

P.S. Its not paint :P