Rear takedown detent

[jeff68]

Anybody see a problem with tapping the 3/32 detent hole #4-48 NF for a setscrew. And replace the teardrop keeper with a split ring lockwasher

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[jeff68]

AR15. Lockwasher in front of castle nut.

 

[Unka-Boo]

I d&t'd the hole on my first pistol build 15 years ago, worked out fine.

 

[jeff68]

I d&t'd the hole on my first pistol build 15 years ago, worked out fine.

Thanks.

 

[Diamondback]

Aero lowers come pretapped for #4-40. Problem is finding anything at a #4 tap brick-and-mortar... I ordered a half-dozen setscrews through a hobby shop on Amazon.

Main problem I have is needing to cut the spring, and then cut any spring you replace it with... but this mod is so simple that other than the extra cost and small parts at an Army-wide scale I wonder why Stoner & Sullivan didn't do it from square one.

 

[jeff68]

Aero lowers come pretapped for #4-40. Problem is finding anything at a #4 tap brick-and-mortar... I ordered a half-dozen setscrews through a hobby shop on Amazon.

Main problem I have is needing to cut the spring, and then cut any spring you replace it with... but this mod is so simple that other than the extra cost and small parts at an Army-wide scale I wonder why Stoner & Sullivan didn't do it from square one.

Thanks. what do you guys think of a split ring lock washer on the buffer tube? No staking or thread lock.

 

[Diamondback]

Got a plan to get it back off again? I prefer PWS ratcheting endplates for that role myself, but they're a little pricey.

Endplate really has three jobs:
1. Maintain alignment between buffer tube and lower receiver--not needed if you have a tube with an extended lip notched for the buffer detent, but that's still quite a bit of stress on that tiny little detent.
2. Something to smash into castle nut and hold it on--again, part of the "alignment locking system" that may not really be needed IF you're willing to bet the farm on the buffer detent.
3. Hold takedown spring inside tunnel, object of this discussion.

 

[jeff68]

Got a plan to get it back off again? I prefer PWS ratcheting endplates for that role myself, but they're a little pricey.

Endplate really has three jobs:
1. Maintain alignment between buffer tube and lower receiver--not needed if you have a tube with an extended lip notched for the buffer detent, but that's still quite a bit of stress on that tiny little detent.
2. Something to smash into castle nut and hold it on--again, part of the "alignment locking system" that may not really be needed IF you're willing to bet the farm on the buffer detent.
3. Hold takedown spring inside tunnel, object of this discussion.

Too much torque required to unscrew?

 

[jeff68]

I did shape my buffer tube to get one extra 360 turn. The plunger was cockeyed and upper wouldn't mate. This is my first AR and build.

 

[jeff68]

upper mated but plunger was cockeyed.

 

[Diamondback]

I'm not sure, TBH. Hell, I don't even use the lockwashers meant for grips... really, in theory if you have a "detent-interface lip" on the buffer tube and a setscrew holding the spring, in THEORY you could dispense with the CN and endplate entirely unless you're using the latter as a sling mount. Then again, in theory if Turd Ferguson had balls he'd be a man...

Do yourself a favor, get a copy of what's called the "23&P" manual--it's what the pros use to maintain and repair 'em for the military.

 

[jeff68]

thanks for the title. Cheers.

 

[jeff68]

Downloaded the title, thanks. have the M16 service manual and "Gunsmithing the AR-15 THE BENCH MANUAL" on Scribd.com

 

[jeff68]

Got a plan to get it back off again? I prefer PWS ratcheting endplates for that role myself, but they're a little pricey.

Endplate really has three jobs:
1. Maintain alignment between buffer tube and lower receiver--not needed if you have a tube with an extended lip notched for the buffer detent, but that's still quite a bit of stress on that tiny little detent.
2. Something to smash into castle nut and hold it on--again, part of the "alignment locking system" that may not really be needed IF you're willing to bet the farm on the buffer detent.
3. Hold takedown spring inside tunnel, object of this discussion.

The PWS one looks great. Thanks

 

[DirectDrive]

Aero lowers come pretapped for #4-40. Problem is finding anything at a #4 tap brick-and-mortar... I ordered a half-dozen setscrews through a hobby shop on Amazon.

Main problem I have is needing to cut the spring, and then cut any spring you replace it with... but this mod is so simple that other than the extra cost and small parts at an Army-wide scale I wonder why Stoner & Sullivan didn't do it from square one.

Yep, 4-40 is the correct size. Get the shortest Allen screw you can find.
I put some AeroShell grease in the pin's detent groove and did not have to cut down my spring.
It was sticky without the grease.
YMMV

Never heard of a "teardrop keeper" so I can't help on that.


ETA:
Any of the detents run smoother for me with a little grease in the track (groove).

 

[jeff68]

So Fastenal had the 4-40 x 3/16 set screw. I cut about an 1/8" off the spring with a dremel cutoff. The "keeper"..my bad, the receiver end plate. Thanks for the heads up Diamondback on the tapped hole. It's an Aero lower, I had no clue. Nice feature. And the rear pivot take up screw is nice.

cheers
PS. still dry fitting. I have Aeroshell grease, Hoppes gun oil and Permatex blue. I'm going for more of the light lube philosophy. I came in on the inexpensive end but will upgrade barrel, trigger.... I want to see the improvements.

 

[v0lcom13sn0w]

Anybody see a problem with tapping the 3/32 detent hole #4-48 NF for a setscrew. And replace the teardrop keeper with a split ring lockwasher

i tap all of my 80%ers with a 4-40 tap and put a set screw in it. cut the length of the screw off of the rear detent spring

 

[jeff68]

I missed any threads on that. And I was kinda proud of myself.

 

[DirectDrive]

I missed any threads on that. And I was kinda proud of myself.

Them threads are that there 4-40

 

[jeff68]

Them threads are that there 4-40

I shouldn't dox the Fastenal in Kelso but they gave me the screw for free.