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9/22/2017 12:11:25 AM
Posted: 8/15/2005 3:47:42 PM EDT
I was attempting to assemble the front takedown pin and had some issues. Under full compression the pin will not go into the hole. The spring checks out for length compared to a known good replacement part. The detent looks different (only pointed on one end) than a replacement one I have. Both pins have the same basic OAL. Is the detent hole too shallow and should I cut down the spring to fit or is somthing else going on?
Link Posted: 8/15/2005 3:56:16 PM EDT
[Last Edit: 8/15/2005 3:56:58 PM EDT by Minuteman419]
I had an Oly do this last week.

I ran a small drill bit into the hole{by hand) and removed some crap like sand.

After that I cut about a coil and a half off the spring.

What kind of lower do you have?

Danny
Link Posted: 8/15/2005 3:56:46 PM EDT
First take a drill bit that just slips into the hole and spin it with your fingers. There are often chips in there that need to be taken out. You should do this with any blind hole on a AR-15 build.
The detent should be the same on both ends IIRC. The one that is flat on one end and pointed on the other is the selector detent.
Link Posted: 8/15/2005 3:58:51 PM EDT

Originally Posted By Big-Bore:
First take a drill bit that just slips into the hole and spin it with your fingers. There are often chips in there that need to be taken out. You should do this with any blind hole on a AR-15 build.
The detent should be the same on both ends IIRC. The one that is flat on one end and pointed on the other is the selector detent.



I've seen several many detents lately that are pointed on one end and flat on the other.

Pointed in towards takedown pin.

Danny
Link Posted: 8/15/2005 3:59:32 PM EDT
The one point detents like the ones I got from Model1 never worked for me I trashed them for the correct ones.
Link Posted: 8/15/2005 4:07:45 PM EDT

Originally Posted By Minuteman419:
I had an Oly do this last week.

I ran a small drill bit into the hole{by hand) and removed some crap like sand.

After that I cut about a coil and a half off the spring.

What kind of lower do you have?

Danny



I checked out the hole and it's clear of debris. So that's not it.

The lower is an Ameetec Arms lower.
Link Posted: 8/15/2005 4:15:04 PM EDT
[Last Edit: 8/15/2005 4:29:44 PM EDT by j3_]
Are you sure you have a takedown/pivot spring and not an ejector/selector spring? Usually the spring will stick out a couple of coils past the top of the lower hole.
Link Posted: 8/16/2005 2:16:10 PM EDT

Originally Posted By j3_:
Are you sure you have a takedown/pivot spring and not an ejector/selector spring? Usually the spring will stick out a couple of coils past the top of the lower hole.



Any good way to tell them apart?
Link Posted: 8/16/2005 4:18:44 PM EDT
The takedown/pivot spring is made of smaller wire and bends easier than the selector/ejector spring. Also the pivot spring is slightly longer than the selector spring.
Link Posted: 8/16/2005 5:15:49 PM EDT
If you get the detent started (I use small needle-nose pliers), you should then be able to use a knife blade (or similar) to push the detent completely into the hole. If you can't easily do this, you've got the wrong spring and/or detent. (Sounds like you've already established that the pivot pin will easily slip into its holes with no spring/detent in place).
Link Posted: 8/16/2005 5:19:25 PM EDT
The depth of the holes for the front pivot pin may differ from time to time.

I have a Frankford Arsenal Lower that I assembled, the pivot pin and spring almost disappeard into the hole, while the Armalite I assembled took a act of god and luck to find the damn pivot pin after it went into orbit around my kitchen.
Link Posted: 8/18/2005 8:48:44 AM EDT
i built on a dpms lower with a kit from model 1 sales and had to cut 2.5 coils off the spring. for some reason the springs are extra long from model 1. use a cheap pair of finger nail clippers or a realy small pair of dikes and just clip .5 of a coil off till it goes. bets of luck to ya.
Link Posted: 8/18/2005 3:26:47 PM EDT
I have the same problem when I installed my front takedown pin.

I knew that I have the correct parts because everything fits except the detent pin won't go down far enough to clear my detent installation tool.

I cut the spring one coil at a time until it the detent would clear.

The spring turned out to be flush with the hole in the lower receiver.

Hint: use a clear plastic bag over your receiver during detent pin installation so you won't loose the detent pin. Always wear safety glasses for safety.

Good luck.
Link Posted: 8/19/2005 8:15:29 PM EDT
I got out thre old wire chopper and cut that spring down to size. It went together ok, the front pin is a bit tight but I'm sure it'll wear in.

Again, thanks to all for the help.

My rifle is now completely functional. Just need a range test...
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