tapping the hole for the rear takedown detent - Page 1

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[ARCHIVED THREAD] - tapping the hole for the rear takedown detent

Posted: 8/26/2014 8:17:41 PM EDT

I have been told that it is possible to tap the first part of the hole for the rear takedown detent so that a screw can be installed that would allow the end plate to be removed without having to mess with the detent. What are the pros and cons of this?

Posted: 8/26/2014 8:21:37 PM EDT

[#1]

Never have to worry about that small spring or detent getting lost any time you change the stock.

http://www.ar15.com/forums/t_3_118/395777_Simple_fix_for_the_rear_takedown_detent_spring_blues____.html

Posted: 8/26/2014 8:49:08 PM EDT

[#2]

timely - I was just searching for the thread about that and coming up empty handed. I'm going to do this for my current build.
Thanks guys!

Posted: 8/26/2014 8:53:44 PM EDT

[#3]

I've done this on most of my lowers. Probably one of the easiest mods. Pay off is only so so, but if nothing else it's a good ice breaker to get your feet wet. I also thread the bolt catch. I've only threaded a couple for the safety detent. Nice mod, but it doesn't leave much room for a spring. Even when the detent pin is replaced with a ball bearing.

Posted: 8/26/2014 8:59:17 PM EDT

[#4]

Do you need to shorten the spring ?
Short 6 - 32 set screw?

Posted: 8/26/2014 9:33:19 PM EDT

[#5]

I used a 4-40 set screw about an 1/ 8th length, cut off the spring for the same length of your set screw, then use a 4-40 tap and tap a bit of the outer end of the hole, a taper tap will need to go a bit deeper into the spring hole, the Allen tool used for this tiny set screw is a .50 size. I purchased a dozen or so off of amazon, works perfect. I might try one for the safety detent on the next project, just need to find a source of the 1/8 ball barrings.
Have fun.

Posted: 8/27/2014 11:15:34 AM EDT

[#6]

I've got a bag of 4-40x1/8" set screws(Had to buy a bag of 100x when I did this).
If you are going to do this mod, send me your address and I'll drop a couple to you.

Posted: 8/27/2014 1:05:51 PM EDT

[#7]

I've done this on all of my builds plus the ones I've helped my brother and friends build. I went to a local fastener's shop to get the set screws. For a couple dollars I came away with enough to mod a small army's worth of lowers.

I always cut the spring down by roughly the length of the set screw. Just take a pair of dikes and snip it off.

Posted: 8/27/2014 2:45:18 PM EDT

[#8]

why are you changing the tube or end plate often enough to make this worth it?

Posted: 8/27/2014 2:52:15 PM EDT

[#9]

My Aero lower came with it tapped so I figured eh, what the hell...used an 1/8" set screw with a little aero shell on it...trimmed the spring...The cats behind right there.

Posted: 8/30/2014 12:45:54 AM EDT

[#10]

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Quoted:
why are you changing the tube or end plate often enough to make this worth it?

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Its nice if your building in phases. I've got a few lowers attached to uppers that dont have stocks yet. It keeps me from loosing rear takedown pins and their parts.

Posted: 8/30/2014 1:24:09 AM EDT

[#11]

I use .22LR conversions almost everytime I go out along with shooting 5.56/.223, so I found the KNS rear takedown pin perfect, it allows easy takedown and you don't need to use the detent and spring. I use them on all my current AR builds.

Posted: 8/30/2014 6:59:24 AM EDT

[#12]

Rear take down yes to the mod with the 4/40 set screw. Safety detent, not so much, about the only good reason to do this one is if you plan on doing bump fire stock but short of that the con's out weigh the pro's.

Posted: 8/30/2014 1:19:01 PM EDT

[#13]

4-40 is good. 6-32 works also.

Posted: 8/30/2014 5:49:37 PM EDT

[#14]

Quoted:
I have been told that it is possible to tap the first part of the hole for the rear takedown detent so that a screw can be installed that would allow the end plate to be removed without having to mess with the detent. What are the pros and cons of this?

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Check your lower before you tap it. Some manufacturers tap the hole. I know AP does.

Posted: 8/30/2014 6:15:18 PM EDT

[#15]

Quote History

Quoted:

Check your lower before you tap it. Some manufacturers tap the hole. I know AP does.

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Quote History

Quoted:

Quoted:
I have been told that it is possible to tap the first part of the hole for the rear takedown detent so that a screw can be installed that would allow the end plate to be removed without having to mess with the detent. What are the pros and cons of this?

Check your lower before you tap it. Some manufacturers tap the hole. I know AP does.

80% I got from Range Tool is also tapped.

Posted: 8/31/2014 3:10:38 PM EDT

[#16]

I discovered today the Sears Hardware store has the 1/8" 4-40 set screws. 20C each. I bought a dollars worth

They also had a 4-40 tap and drill bit for 4 bux. The store is walking distance from my house, and don't ask how I know !

Posted: 9/2/2014 9:52:56 AM EDT

[#17]

thanks for the info guys i think ill give it a shot. now i have to decide whether i want to finish my pistol bulld, or my hunting build first.

Posted: 9/2/2014 11:08:19 AM EDT

[#18]

Quote History

Quoted:
why are you changing the tube or end plate often enough to make this worth it?

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I built several of mine as pistols while awaiting the stamp. Also allows you to build the lower and not have to keep track of the spring, detent, and rear takedown pin while waiting to get the stock. You'll still have to keep track of the buffer retaining pin spring, but that's only 2 things rather than 5.

[ARCHIVED THREAD] - tapping the hole for the rear takedown detent

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