I'm going to build an AR-15

[Guest]

My PSA lower seems to be pretty well-made. The only very small flaw I found is that the holes for the two roll pins (bolt catch & trigger guard pins) were a couple thousandths too small, and I had to carefully drill them out with a number drill and pin vice to get the pins to punch in. Not a big deal, as far as I am concerned.

For $49, I don't mind spending 5 minutes to take a few thousandths out of the holes. Probably just a freak occruance on mine, I doubt they would ship a whole run with small holes.

Assuming they are the correct dimensions, here are CAD files I found for the AR-15/M16. http://www.biggerhammer.net/ar15/cad/

Edited December 21, 2011 by Guest

[Dolomite_supafly]

You do not have to add any other holes than what are in the standard AR15 lower.

All you will need is the DIAS, M16 carrier, M16 trigger, M16 selector, M16 hammer, and M16 disconnector.

+1

The RDIAS goes under the rear lug of the upper receiver. No need to drill any holes in the receiver. If you do drill the holes for the FA parts in your receiver you are in possession of a MG even if you do not have the aprts installed. Same as with AK's that have the pin holes for the FA parts.

The RDIAS can be swapped between guns providing the RDIAS is what is registered, the parts are present and the lower is a low shelf lower. You also need ot make sure the bolt carrier is RDIAS friendly otherwise you are going to have to have it milled.

Dolomite

[mikegideon]

My PSA lower seems to be pretty well-made. The only very small flaw I found is that the holes for the two roll pins (bolt catch & trigger guard pins) were a couple thousandths too small, and I had to carefully drill them out with a number drill and pin vice to get the pins to punch in. Not a big deal, as far as I am concerned.

[Dolomite_supafly]

My PSA lower seems to be pretty well-made. The only very small flaw I found is that the holes for the two roll pins (bolt catch & trigger guard pins) were a couple thousandths too small, and I had to carefully drill them out with a number drill and pin vice to get the pins to punch in. Not a big deal, as far as I am concerned.

For $49, I don't mind spending 5 minutes to take a few thousandths out of the holes. Probably just a freak occruance on mine, I doubt they would ship a whole run with small holes.

Assuming they are the correct dimensions, here are CAD files I found for the AR-15/M16. AR-15 CAD Files

If they were out of spec it is probably from the build up from either annodizing or coating. If they seem tight, which is a rarity, I just muscle them in because the pin does give some as does the aluminum. Afterwards you will, without a doubt, know the pins will not back out. I have found the roll pin punch made specifically for the bolt catch makes life so much easier. It is the one with 1/2 the shaft missing to clear the raised portion on the magwell. Without the correct punch the pins can be hard to get started or get in.

I suspect the holes were not out of spec but they probably felt that way to you because you are relatively new to the platform and have no comparison. They do take some effort to get them to go in otherwise they would work loose. And that isn't meant to be a hit on you because the first few lowers I put together I thought the same thing. Now that I have dozens of builds under my belt I know they just feel that way.

Dolomite

[R1100R]

The PSA's I have built had some kind of paste or dried oil in the small holes from tapping/drilling them. To me it was the same color as car wax. I just cleaned them out and had no issues.

[Guest]

I suspect the holes were not out of spec but they probably felt that way to you because you are relatively new to the platform and have no comparison. They do take some effort to get them to go in otherwise they would work loose. And that isn't meant to be a hit on you because the first few lowers I put together I thought the same thing. Now that I have dozens of builds under my belt I know they just feel that way.

Whatever it was that was in the holes, they were slightly undersized (according to the CAD drawings I found). I know this because although the hole for the bolt catch pin is supposed to be 0.097, I could not get the 0.096 number drill (#41) to work into the hole. Drilling with the #41 drill in a pin vice, careful not to wobble the bit, did remove enough material to allow the pin to be hammered in, but it still required a fair amount of force with the 4oz ball peen hammer. Nowhere near as gently as in the Brownells instructional videos.

That said, so far I am completely happy with the PSA lower, and would buy another if I was starting another build.

Oh, another little trick that may be common knowledge, but I hadn't seen it anywhere, will help when installing the pivot pin dentent and spring, if you don't have the special-purpose tool. After installing the spring and the detent, compress them both into the detent cavity in the lower receiver body carefully with an Exacto kife blade. Because of the thin profile of the blade, you will be able to install the pivot pin over the knife blade, and then remove the knife blade, allowing the pivot pin detent to engage the slot in the pivot pin.

Edited December 22, 2011 by Guest

[mikegideon]

Oh, another little trick that may be common knowledge, but I hadn't seen it anywhere, will help when installing the pivot pin dentent and spring, if you don't have the special-purpose tool. After installing the spring and the detent, compress them both into the detent cavity in the lower receiver body carefully with an Exacto kife blade. Because of the thin profile of the blade, you will be able to install the pivot pin over the knife blade, and then remove the knife blade, allowing the pivot pin detent to engage the slot in the pivot pin.

There's one video out there that uses a box cutter. That's how I do mine. Haven't launched a spring yet.

[Dolomite_supafly]

I've been meaning to make a tool for installing those. It just slipped my mind with the holidays and my son's graduation coming up in January.

Dolomite

[mikegideon]

I've been meaning to make a tool for installing those. It just slipped my mind with the holidays and my son's graduation coming up in January.

Dolomite

The knife blade trick works so well that I kinda quit wanting a tool.

[Dolomite_supafly]

Problem I have making the tool is I have to figure out how to take the front pin out to make it. That or just buy another lower .

Dolomite

[mikegideon]

Problem I have making the tool is I have to figure out how to take the front pin out to make it. That or just buy another lower .

Dolomite

Cut the pin in half and just buy another pin. Dremel cutting wheel.

[Capbyrd]

If they were out of spec it is probably from the build up from either annodizing or coating. If they seem tight, which is a rarity, I just muscle them in because the pin does give some as does the aluminum. Afterwards you will, without a doubt, know the pins will not back out. I have found the roll pin punch made specifically for the bolt catch makes life so much easier. It is the one with 1/2 the shaft missing to clear the raised portion on the magwell. Without the correct punch the pins can be hard to get started or get in.

I suspect the holes were not out of spec but they probably felt that way to you because you are relatively new to the platform and have no comparison. They do take some effort to get them to go in otherwise they would work loose. And that isn't meant to be a hit on you because the first few lowers I put together I thought the same thing. Now that I have dozens of builds under my belt I know they just feel that way.

Dolomite

Roll pin punches are almost a necessity. However, I don't use one. I use vice grips to hold the roll pin closed, slide it in about halfway and then hammer it home. Works great but you can crush a roll pin if you set your vice grips too tight.

[mikegideon]

Roll pin punches are almost a necessity. However, I don't use one. I use vice grips to hold the roll pin closed, slide it in about halfway and then hammer it home. Works great but you can crush a roll pin if you set your vice grips too tight.

I have roll pin punches, and it can still be a bear to get one started. I think the worst one may be the gas tube pin. One of these days, I'll get some roll pin starter punches.

[Guest 6.8 AR]

I use long nosed needle nose pliers on that pin.

Sent from my iPhone using Tapatalk

[mikegideon]

I use long nosed needle nose pliers on that pin.

Got any tiny dents in your forehead?

[gunrunner32]

Dolomite, you can make on like the Brownells one (PIVOT PIN DETENT INSTALLATION TOOL - Brownells) I've got one and they work great, until I got wise and bought one I was using the boxcutter method...thankfully I never cut myself. I will have to agree that roll pin punches are a must if you plan to assembly more than 1 AR, then again there are a lot of other weapons I've used mine for.

[Guest WyattEarp]

was hoping to get in on the Palmetto Arms lowers for $50, but the sale is over conveniently when I finally have some money grrrr.. if anyone knows where some good lowers are for a good price please let me know, I'm ready to start!

[mikegideon]

Joebob usually has reasonable prices with the TGO discount. They won't be 50 bucks. Transfer thru D&T

EDIT: Spikes for $79.95 less the TGO discount

Edited January 12, 2012 by mikegideon

[Capbyrd]

Surplus Arms and Ammo Lower

Surplus Arms & Ammo LOW15 Stripped AR Lower Receiver

69 bucks shipped.

[Guest WyattEarp]

Surplus Arms and Ammo Lower

Surplus Arms & Ammo LOW15 Stripped AR Lower Receiver

69 bucks shipped.

outstanding, thanks!!!

[Capbyrd]

No problem. This rifle is built on that lower and I have zero complaints!

[Guest WyattEarp]

removed.

Edited January 16, 2012 by WyattEarp

[Capbyrd]

Nothing wrong with it. But you can build the Surplus Arms lower cheaper.

[Guest cmchap76]

Palmetto makes good stuff. Can't go wrong with Spikes Tactical either.

I can't say I agree with this statement, YET. But I hope to be able to very soon. Last week I ordered a complete upper from PalmettO State which should be delivered on 1-16-12. I will be puting it on a Spike's Tactical stripped lower that was put together with a Spike's lower parts kit, both purchased at D&T Arms in Rivergate! So hopefully here soon, I will be able to vouch for the above statement.

[Guest WyattEarp]

picked up an Aero Precision complete unassesmbled lower for $149.99 + 15.99 shipping. Had to consult with Dolomite first, since my knowledge is so limited, but I was told that was a steal!!!

So halfway there, and spent A LOT less than I figured I would have to.