AR Builders Any bad lower/lower parts kits combos? Which do you love and hate?

[g3man]

Usually in building an AR lower any body that has built a few has had an issue here and there with specific parts kits not being 100% compatible with specific receivers. Usually alway when they are from 2 different manufacturers. I personally had an issue with the Tactical innovations receivers not being compatable with the bolt hold open in the Stag parts kits. What have you used that works and what have you had problems with?

 

[spearheadersarge]

PSA is good to go! The fit and finish on my PSA M forgery is absolutely fantastic. The Magpul LPK went together quickly and accurately and it was my first build to boot

 

[Hop]

I've never had any trouble with any brands listed below.

LPK's that I've used:

• Del-ton (x3) - cheap! one has an excellent trigger, 2 others were good w/ minor creep. All are heavy.

• Colt (x2) - drag a brick through gravel feeling trigger

• PSA (x3) - not enough time behind these to evaluate

• RRA w/ 2 stage NM triggers (x2) - always seems to get dinged for durability but 1 of these has gone thousands of rounds w/ a Slidefire stock

• G&R Tactical (mixture of Colt & FN parts. Great feeling safety, trigger ~same as Delton but a bit lighter. fcg pins in spec but on the small side)

• Geiselle FCG - not a full LPK, only the trigger and it's amazing

Lowers I've used:

• Colt (x1)
• Superior Arms (x3) - grip width spec'd on the wide side
• Noveske (x1) - fcg holes in spec on the large side
• RRA (x2)
• PSA (x2)

 

[g3man]

Amen on the Colt FCG!!!

 

[melensdad]

I always recommend that people stay away from DPMS lower parts kits. I've probably built close to 100 AR15s and that is the worst brand that I've found for quality control in their small parts.

YMMV

 

[Steve B]

I've built a Sarco kit on a Surplus a Ammo & Arms lower and a Del-Ton kit on a Delaware Machinery lower. Both were fine and cost was reasonable as well at around $500 each.

 

[Principal Skinr]

I haven't installed mine yet, but I like how CMMG packages their LPK's. They separate the parts into color coded packets. That's a nice touch.

I've heard good things about them, and they can be had at a reasonable price. I'll be installing it in January at the build party at Marion County Fish and Game. We'll see how the trigger works out.

The best standard triggers I've used are on my Remington R15 (Bushmaster), and my Ruger SR556. I also have Double Star, which is good, and PSA, which is really gritty, but only has 50 rounds through it.

By far, the best, though, is that Remington trigger. I'm not sure if Bushmaster tweaked it for this gun, being that it is primarily a hunting rifle . It feels like lighter pull than the others by a pound or so, and it is smooth.

The only lower I've had that wasn't good was a Rogio (sp?). The rear takedown pin hole was not drilled straight. The rear pin was so tight with any upper, that it had to almost be pounded out to separate the lower and upper.

I'm not sure the standard AR triggers aren't somewhat of a crap shoot for how they feel. I've had two of the same brands, in the same branded lowers, that felt different. (Double Star LPKs, and Double Star lowers.)

 

[Ripper]

This is just the topic I've been waiting for. I am getting ready for my very first AR build, and I'm a AR Virgin to boot!

I've got a smith lower/cmmg parts/and pmags that I'm picking up from a friend. I don't know anything about this so I hope I'm on a good start?

Any help would be greatly appreciated

 

[Psode27]

I have built a couple ARs using DPMS triggers and couldn't agree more with the above statement! They will be replaced as money and other projects allow! Pretty poor. Lowers used were 2 Anvil Arms lowers, and 2 DPMS lowers. No range time yet on the most recent build but I am very pleased with the "livingroom dry-fires" I've had with my Novekse lower/CMMG LPK. The LPK was about $60 locally, came packaged wonderfully (as stated above), and even had a sticker for the toolbox in the garage!

 

[OZESS]

I have used dpms and found them to be great rock river were hard to mate with model 1 uppers and buying from r guns they look to have good prices but i waited 4 months and they change the date longer so I told them send my money back.you want good price and on time Model 1 sales great place.

 

[OZESS]

Also AGI gun course for the ar is about $45 dollars well spend it has alot of info
that new builder can use to make the gun building more fun and save your money
not to ruin the lower .

 

[Cerberus]

I always recommend that people stay away from DPMS lower parts kits. I've probably built close to 100 AR15s and that is the worst brand that I've found for quality control in their small parts.

YMMV

While I've only did one build with DPMS parts, lower and LPK, my experience reflect Mel's. I fought that build. Parts or holes weren't always cooperative. My PSA/LRB lower build went together like they were created for each other.

 

[dieselrealtor]

(drank the AR coolaid)
learning now, thread tagged

 

[greyhound47]

The only two I have seen and had trouble with myself were Rock River and DPMS. You can't go wrong in my experience with Stag Arms or CMMG.

 

[N_K_1984]

The Good, The Bad, and the Ugly

Here's some of my recent experience on lowers I've assembled for friends and family. They supplied the lowers and LPK's.

Tactical Machining AR10 Lower/DPMS 308 LPK: Brother in Law bought the lower, was apparently told by Tactical Maching to use a DPMS parts kit, as it is the best compatability. Long story short; total nightmare. Take down pins were really loose, the detents will barely hold, the detent springs in the kit appear to be too short(???), the bolt catch pin hole was threaded for use with a set screw (not provided). Tactical Machining made it right, they sent the set screw and new (longer) detent springs. It took a couple weeks to get everything, but it works. The lower is still a sloppy fit. My Brother in Law is ok with it, as he is in love with the gun, as a whole. I would have already sold it (or tried to) and moved on to the next project.

Roggio Arsenal LLC Lower/LPK: trigger guard spring pin, and bolt catch pin both went in SUPER tight, almost too tight for comfort. The "Mil-Spec" buttstock extension (buffer) tube was also a SUPER tight fit, again almost too tight for comfort, to the point of my contemplating using a pipe wrench to fully tighten it. I managed to get it installed, by hand, lubing both sets of threads, tightening two turns, loosening 1 turn, disassemble, clean threads and relube, repeat process until fully seated. I then disassembled, cleaned off all the lube, and then reinstalled. At that point, it went together as it should. It was still a huge pain.

Indy 1500 buy: Grim Reaper Lower/CMMG LPK: Great quality on the lower, Everything went together nice, snug, and smooth. Everything that the LPK came with, that is. It was probably just a fluke, but the kit was missing the buffer detent and spring, trigger guard spring pin, and the hammer(?). Luckily, for my buddy, I had extras in my parts bin.

PSA Lower/LBK: (yes, LBK, it's their Lower Build Kit): I have built 3, for 2 buddies, 1 for myself: No issues. Great quality on the lower. Everything went together nice and smooth, as they should, no missing parts.

Rock River Arms Lower/ RRA LPK: Aside from the PSA kits, this has been the best as far as fit and finish. The RRA's that I've assembled have gone together butter-smooth. The lowers are high shelf, but who really cares? The price was more of a premium, but I'm not sure if you're getting any better quality than you would with PSA. All I know is that pins went into holes nice and smooth, and any/all tapped holes & threads went together nice, snug, smooth, and tight; as they should.

DPMS Lower/DPMS LPK: much like RRA or PSA, no issues, no complaints.

Surplus Arms & Ammo Lower/PSA LPK: I've put together 2 of these combos. Great quality on the lower, Cerro Forge keyhole marked. PSA LPK installed no problem, 100% compatable. No issues, no complaints.

Delaware Machine Co. Lower/PSA LBK: Same story, different Lower. No issues, no compaints.

So in my experience, for what most of us are going to use them for, you can't go wrong with most any lower and LPK, as long as you avoid Roggio Arsenal and Tactical Machining (for an AR10). My

 

[Newbomb92]

I've never had a problem using any combination below....

Lowers- PSA, Noveske, Stag, Wilson Combat

LPK- PSA, Daniel defense

 

[davedolli]

I have built 10 to date and never had a problem with any of the various LPKs that I have used. Any more when I need one I buy from PSA when they are on sale. A couple of times I have used there 39.99 kits that did not include the FCG, and used take off parts that I had upgraded on another rifle.

Dave

 

[ghuns]

I have only built 2 so far. Both used Surplus Ammo & Arms lowers and CMMG LPK's. Both worked like a champ. Not the best trigger, but not that bad. The color-coded bags and you-tube video are very helpful for a newbie. The SAA lowers also have the detent spring hole, that is under the end plate, tapped for #4-40. Very nice touch to keep that spring from flyin out.

 

[SmileDocHill]

I have an older Colt HBAR that has the off size (can't remember if it is larger or smaller) holes for the LPK pins. Nice rifle, highly accurate but kinda annoying to say the least that it isn't totally compatible with my other AR-15 parts.

 

[DownByTheTracks]

I've used the DPMS LPK with pretty good success.

Model 1 Sales LPK = Junk.

DPMS receivers are okay. Nothing special.

PSA receivers are great for the money, their LPKs are pretty good.

R-Guns receivers are no bueno.