AR Lower Parts Kit

jwrowland77

New member
Well, I was lucky enough to find a lower receiver today and have been looking at lower parts kits.

This will be my first ever gun build of any sort. I'm looking for a little guidance as to which lower part kits are quality ones. There's so many out there, and don't want to buy one that a piece is going to break in no time flat.

The lower receiver is mil spec, .223/5.56.

Any help or advice is greatly greatly appreciated.
 
I've built a handful of AR's and have used Rock River LPK with their two stage trigger in every one. I've never had a problem and really like the trigger.

One suggestion... when you buy a LPK also buy a spare pin and spring parts kit. They are short money and when one of your detent spring goes flying across the room into places unknown you'll be glad to have a set of extra parts.
 
Well I took the plunge. I ordered a Daniel Defense from Midway. They are on backorder but only until Monday 12/31/12. Most other places were all on backorder and for like 6-8 months. Crazy!
 
I've built a bunch of AR's and have used all manner of LPK's. There's not much difference that I can see between a Colt and a DPMS vs. RR or anyone else on dimensions and proper fit. There might be a difference on the finish of the parts.

Here's a near-mandatory tip: Get a set of REAL roll pin punches. Don't just use a pin punch intended for straight pins and try to nail the roll pins in with that. The end of a pin punch invariably slides off the roll pins and you bugger up the finish of the AR. Get a real roll pin punch set and do the job right - the finish will look much better when you've not nailed a punch into it.

Some optional, but useful tips:

1. When you're putting in the pin for the trigger guard, put the back side of the trigger guard on a block of wood or a rubber hockey puck, so that you don't blow off the back flange of the guard.

2. When you're putting in the roll pin for the bolt stop, put the pin in from the rear of the receiver and put a piece of masking tape on the side of the receiver to protect the finish. Be gentle and observant of the pin alignment so you don't break off the bolt stop "ears."

3. For the takedown pin detents, keep them in place with a slave pin (you can make this from a piece of drill rod) as you start the pin. Put the slave pin in from the left side of the receiver, then gently push down on the detents with a probe or small screwdriver, and push the slave pin far enough to capture th detent.

Put the takedown pin against the slave pin in the hole, then gently push through from right to left. Wha-la, no more flying detents.

4. Put the pistol grip on only partly tight before you have the safety installed. It's much easier to fiddle the safety into place with the detent under the grip a bit loose than to try to ram the safety lever into place against a full-push detent.

Lastly: Wear safety glasses when putting together guns with lots of springs and detent plungers that can go flying. There's no point in getting poked in the eye with a spring or detent.
 
I've built a bunch of AR's and have used all manner of LPK's. There's not much difference that I can see between a Colt and a DPMS vs. RR or anyone else on dimensions and proper fit. There might be a difference on the finish of the parts.

Here's a near-mandatory tip: Get a set of REAL roll pin punches. Don't just use a pin punch intended for straight pins and try to nail the roll pins in with that. The end of a pin punch invariably slides off the roll pins and you bugger up the finish of the AR. Get a real roll pin punch set and do the job right - the finish will look much better when you've not nailed a punch into it.

Some optional, but useful tips:

1. When you're putting in the pin for the trigger guard, put the back side of the trigger guard on a block of wood or a rubber hockey puck, so that you don't blow off the back flange of the guard.

2. When you're putting in the roll pin for the bolt stop, put the pin in from the rear of the receiver and put a piece of masking tape on the side of the receiver to protect the finish. Be gentle and observant of the pin alignment so you don't break off the bolt stop "ears."

3. For the takedown pin detents, keep them in place with a slave pin (you can make this from a piece of drill rod) as you start the pin. Put the slave pin in from the left side of the receiver, then gently push down on the detents with a probe or small screwdriver, and push the slave pin far enough to capture th detent.

Put the takedown pin against the slave pin in the hole, then gently push through from right to left. Wha-la, no more flying detents.

4. Put the pistol grip on only partly tight before you have the safety installed. It's much easier to fiddle the safety into place with the detent under the grip a bit loose than to try to ram the safety lever into place against a full-push detent.

Lastly: Wear safety glasses when putting together guns with lots of springs and detent plungers that can go flying. There's no point in getting poked in the eye with a spring or detent.

Wow. Thanks for the great tidbits there. I will be printing these off for when I get my parts kit. Hopefully Midway will have them Monday and then hopefully I'll have them next week sometime.
 
For step #3 outlined by wyop, consider doing the pivot pin deed inside a large clear plastic bag. That way, when you launch the detent, (and you will), it stays inside the plastic bag and doesn't fly across the room to get lost in the carpet.
 
JP has a really nice kit WITHOUT a trigger/hammer. If you plan on running an aftermarket trigger that's a good option, as the JP kits I've picked up have been about $20 cheaper. Plus, they'll deal to you from the factory.
 
Man I wish that AR parts were in stock and as cheap as they were just a few months ago! I am itching to build a whole new setup!

jwrowland77 good luck on your new rig.
 
Thank you. A lot of the kits or already assembled pieces are out of stock, so I'm going to build everything from scratch. Easier to find that way right now I've noticed.
 
my CMMG LPK was $50 and works perfectly well. I agree with Rich C. I had to get a new rear takedown detent and spring when i switched my stock.

Whoops
 
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