WarriorDriver

want to build my own AR, anyone got an extra?

Thanks

Mic

I actually have a spare lower with LPK installed and about 30 rounds through it, but I would not feel comfortable selling it to anyone I know, unless that person seriously wants to build something that is not accurate what so ever.

It's an S&W M&P15 Lower. The most sloppiest piece of shit ever.

Someone with some patience and time, who would want to make some shims, could make it work. I may end up doing that one of these days, if I don't sell it, and just make it a dedicated .22 rifle.

200 takes it if you want it. It already has the LPK installed. I just basically want to get out of it with the LPK what I can buy a new stripped lower for. Some may think that is high, for something I admittedly say is a piece of shit, but *shrug* I can make it word down the road, or someone can get one now and put time into it. Either way, I don't care =)

WarriorDriver

Hmmm, your quite a salesman, but Id like something that will be accurate. Thanks though!

Mic

LOL, like I said, I wouldn't want to sell it to anyone I knew, unless they really wanted it!

WarriorDriver

I want that .50 pistol you have :P big fire!

thejrod

Interesting... I thought M&P15s were pretty decent. Any chance your LPK was out of spec?

And to the OP - Rainier Arms, LLC™ | Taking the AR15 to new heights. has CD lowers for 175. And he's local.
And he has a ton of other shit for generally outstanding prices.

WarriorDriver

Thanks, wonder if I can just pick it up there.. What is a 'bad' lower to stay away from?

Coug91

Lower makes the upper not accurate... that's a new one.

Mic

LPK would have nothing to do with side to side play, not to mention the gap between the lower and upper.

Mic

You might want to retake geometry then.

If your upper is not tight to your lower, it means that the barrel (upper portion) will move during firing. Although extremely slight in movement (a half millimeter or so), that ends up inches of angle deflection at 100 yards or more.

Edit: If you were not aware that the lower has just as much to do with your accuracy as your round, barrel and upper with an AR, then you have been mistaken or told some very wrong advice.

Colt even recognizes this, which is why all of their own rifles come with an accuwedge installed, to help take up the slop. If your barrel is not tight with the rest of the gun, you cannot expect accuracy.

It is why in Match built AR's, they match the lowers and uppers based on measuring them independently.

thejrod

As long as it's to full mil specs, then brand doesn't really matter.

Some Bushies didn't used to be milspec, Colts use a weird size pin. RRA is odd too I believe. Most of the rest are good.

FatFugg

Lowers are pretty readily available again. If you are going to buy from a dealer, I would make sure you register it as a pistol so down the line you can build it into either a pistol or rifle. If your interested PKFirearms has complete Rock River pistol lowers available right now. PK Firearms | Online Store

Coug91

Fair enough... thanks

Mic

Only reason I know a lot about this subject, is I spent a lot of time researching how to build a highly accurate AR. One of my future projects I want to build is a long range AR in .223.

Firing 75 grain, hollow point rounds (The largest possible round to fit in a clip), it is possible to be accurate at up to 800 yards or more. There are also people who hold records at a mile with them. This is rather an interesting concept of development on the guns. I really just want a .223 that will do around 500 to 600 yards.

Besides getting into ballistics in the round itself, there were major things that they recommended.

A heavy barrel was a must. Heavy barrels absorb the vibrations during firing better than a light barrel. When you fire, the propellant as it is burning, and sending the bullet down the bore, creates vibrations. Even if your gun, is somehow perfectly held in place by mechanical means, these vibrations will cause your grouping to be off. Hence why Heavy Barrels are preferred. This is where Cryo treating comes in as well. Cryo treating helps strengthen the barrel, allowing it to absorb even more vibrations.

Your upper "floats" on what you hold. You have 2 pins that connect your lower to your upper. Your buttstock and your pistol grip are part of the lower. This is where the majority of your control comes from when aiming. Your hand on the handguard helps steady it, but it is not what is taking the brunt of the force. If your upper is not tight to the lower, and there is a considerable amount of play, you need to find a way to help take up that slop. On most AR's, it's a simple 2 dollar purchase to "help" by purchasing a accuwedge. It fits under your rear takedown pin where the DIAS (Autosear) goes on the M16. It puts pressure on the upper receiver, forcing it upwards to tighten it. This helps get rid of your up and down play. However, in the case of the S&W I have, it literally has a noticeable amount of side to side play. The wedge can help a little with this, as it puts pressure upwards, and therefore, helps keep it from rocking a little, but the S&W is not DIAS cut, so a accuwedge does not fit.

One article I found, about accurizing a AR, the guy went to the hobby store and bought a very thin sheet of brass. He cut it to shape, bent it, made sure the hammer would travel through the hole he cut, and basically made an insert that went the full length of the lower. Not completely sure what the lower was he was using, but this was making a Match Rifle with off the shelf parts, instead of paying a premium of having a manufacture "match" him a set.

Free Float forgrip. You always want to take as much pressure off of the barrel as possible.

Proper barrel and bolt headspacing. This goes along with your rounds as well. Most everything else becomes preference of the shooter like trigger crap, spring tensions, loads, etc.

Anyways, I am just going on and on...

WarriorDriver, if I was to recommend a lower, just on pure beauty of how it is cleaned up and great fitting, I would go with a Defensive Edge SLR15 lower. They have a huge CY6 stamped on the side. It also comes with a Winter Trigger Guard, and a set screw to help put pressure on your disconnector to take up some trigger pull.

DPMS/Bushmaster/Remington - These are all going to be the relatively the same. All done on Common Machinery (All the same company).

Tactical Innovations out of Idaho, who manufactures for Spikes, Denny, and a handful of others.

SNS out of Snohomish - I looked these lowers over at the show, and they are cleaned up really well. Much better than a lot of the big shops. I know a couple people who are extremely happy with the quality and have built multiple AR's off of SNS lowers. Plus they are local! But unless you come down here to Gun Shows, it will most likely be hard to track one down right now.

FatFugg

Just out of curiosity have you tried this with multiple uppers? Just wondering if maybe you had an upper & a lower the were at opposite extremes of tolerances & just didn't match up.

Mic

Actually, yes. I have 4 Uppers.

Coug91

I had a Tactical Innovations lower that when mated to the spikes upper, I had to use a brass hammer to seat the takedown pin and to take it apart. not field stripping friendly - so I sold it with a stripped LMT upper that it was a near perfect match to - but could take apart without a hammer.

FatFugg

I don't know how serious you are about getting a lower, but PK has several differant Rock River lowers available for very fair prices. Most of them would fall into $10.00 to $12.00 for shipping, so all you would need to do is figure out what FFL you would like it hipped to! I don't know about over there, but over here my favorite shop will do transfers for $25.00 for anyone.

PK Firearms | Online Store

Mic

Wow, that's really surprising. Tactical Innovations is who makes Spikes Lowers.

Coug91

And Denny's Tactical, and a few other "niche names' that I forget.

Jakey poo

I have a few LRB stripped lowers and one with the LPK installed.

FatFugg

Did you ever get a lower?

Pk has a decent selection available.
PK Firearms | Online Store

There have also been some decent deals popping up on Gun Broker lately.

WarriorDriver

I didnt, every time I get the funds to burn, something takes a dump, or bills pop up.. now Ive had two computers fail, so there goes my ar lower fundage... sigh...

sunofnun

i'm looking for a LPK if anyone has one laying around..

FatFugg

If it were me I would send an e-mail to PKFirearms & ask them if they happen to have a LPK they would be willing to separate from their kits that they have where they sell you a lower with a RRA LPK. In the past they have been willing to do similar things for me. It's worth a shot!

hubers454

last one my sons freind bought was $89 in shotgun news, call seller and see if there are any dealers in your area that has a ffl on file

WarriorDriver

I actually do have a lower now, so Im looking for the rest of the parts to complete it.

hubers454

Model 1 Sales they have the best quality parts kits ask Kolat