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Old 10-13-2019, 10:45 AM   #1
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Joined: Apr 2017
From: USA

Posts: 1,247
annoying detents in AR-15

the detents and springs in the AR's lower are a pita. So drill and tap the lowers for the safety plunger and the rear takedown pin, and dont have the springs protruding and unsupported, easily lost as you remove the stock or the pistol grip. The plunger for the rear take down pin is often too short, which can can let the pin fall out of the takedown pin hole. Make a new pin out of a masonry nail, and have it 3/16" longer than the original detent pin, with the same little retention nipple seen on the safety spring plunger in a 1911. This nipple is a tight fit in the end of the detent spring and the longer pin can't fall out of the hole, anyway. When you remove the allen screw, you can shake out the pln and the spring and those two parts will remain together.

The safety plunger spring hole is mostly in the pistol grip, making it a huge pita to reassemble the pistol grip to the lower. So drill and tap that hole in the lower also and install the allen screw. Both of these mods involve shortening the spring a little bit. If you cut a little access slot in the end of the safety itself, you can insert the tip of your knife, depress the safety plunger and thus, free up the safety for removal out of the other side of the lower, without having to bother with the pistol grip at all.

Another buttplate, a couple of 1.5" long, 10-32 screws, 1" pieces of tubing that telescope around the screws. a couple of lock washers and nuts, serve to extend the butt-length to properly fit a full sized man, which lets you more swiftly shoulder the rifle and be looking down the sights as you should be.

The pistol grip is 3/4" too long, pointlessly complicating concealed carry of the rifle under your clothing. If you'll find the correct allen wrench for removing the cap screw that mounts the pistol grip onto the frame, you can weld the allen wrench into the head of the screw, and weld a little rod on the end of the allen wrench, creating a t handle on it. Then you can easily remove and replace the pistol grip without tools, when extreme concealment of the rifle is required. Ditto a wrap of of nomex around the barrel and the gas tube, after you remove the forends or free float tube, whichever you have.

Stoner should have had enough brains to fix all these shortcomings in the original design, or some AR-maker should have done so since. Sheesh, they are obvious, easy to correct. and would make good selling-points for their AR's, if done tastefully. The hollow of the pistol grip can easily be modified to hold a couple of the required allen wrenches for a detail stripping of the lower, if that would ever be required (very unlikely)

However, I'm just a troll who doesn't know a THING about guns.

Last edited by boati; 10-13-2019 at 10:52 AM.
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Old 10-14-2019, 06:09 AM   #2
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Joined: May 2004
From: Central Arkansas

Posts: 5,607
I'd imagine that threaded aluminum subjected to the rigors of semiauto rifle use would strip fairly easily. The spring & detent approach almost certainly makes it cheaper to manufacture and has worked fine for 50 years; which is a minor thing in my world. What is a major thing, is that it allows servicing of the rifle without having to carry separate tools. That's a huge thing.

Fwiw, I don't recall anyone saying you don't know anything about guns.
Old 10-14-2019, 11:21 AM   #3
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Joined: Jul 2019

Posts: 963
The tapping of the holes for the springs and putting a set-screw in them is a known and good modification - thanks for sharing it.

As far as the other stuff, I guess it all depends on your application, so it could be useful to some folks.

I've never bothered with tapping the holes and installing set-screws, as for me they aren't an issue.

There's tools out there that simplify the installation and removal of the various detents. They make setting up the take-down pins a breeze. I think I paid 5-6 dollars on amazon for a no-name set of them.

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