I tried to push the damn thing in, but it seems like once the button is flush with the side of the lower, it hits a wall and stops. Do I need to use more force to get the damn thing in there haha?

Can you drop the button into most lowers without any force?

Pics would help. The button shouldn't have to be pushed in any farther than flush if that far.

Oh my gosh, never buy a NFA lower (its all I could get ok?). 3 hours later after sanding the shit out of it to get parts to fit and i am still not done (granted this is my first build).

Here is a pic. Any ideas? It will not go in any further.


image hosting sites

 Is that plastic?

OK, that's not what I thought when I read the title.  To some of us, "NFA" means "National Firearms Act," and refers to Title II firearms.

I'll bet I'm nowhere near the only one who thought that, either...

I have never had a problem with mine but I bought mine as a complete upper...  Are you using NF LPK or someone else's?

Youre doing it wrong if I recall correctly. You should be pushing the other piece through from the opposite side and screwing the button on to it.

http://www.ar15.com/forums/t_3_4/226782_Assemble_your_own_LOWER__UPPER__FREE_FLOAT__TRIGGER__GAS_BLOCK___Step_by_step_instructions_.html

OP, is this your first build?  And do the NFA lowers have special parts kits or do they use the standard LPK?  If they are different, the size may be off enough that a standard LPK won't fit, but I don't know as I've never used one.  The mag release is usually assembled by placing the L shaped mag catch with the threads facing to the right through the left side of the lower.  The mag catch spring is then inserted onto the threaded end from the right side of the receiver.  You then place the button into the hole from the right side and push it in, while at the same time turning the L shaped piece clockwise, screwing it into the button.  When installed correctly, the threaded piece should be flush with the outside of the hole on the button.

At 2:12, my button will not go in! I tried a ton of pressure with no results.

Thanks, but I read that. I am not that stupid haha

Here, at 2:12, he pushes the button in all the way. Mine doesnt budge from sitting flush with the receiver.

Its a PSA MOE lower build kit.

Uhh, no. Pretty much just you. There's a gazillion mentions of NFA in this thread, and none of them refer to the National Firearms Annoyance.

Only to get it started.

When I put my NFA lower together with a PSA LPK, I found a lot of the parts to be a tight fit (magazine lever, bolt catch, fire selector). Took a Dremel and file to certain parts so everything works smoothly.

The magazine release lever must be longer on the NFA kit because my PSA stuff only catches about 1/2 the threads on the button.

Okay, that guy went to the extreme, it doesn't have to go that far, i've never used anything but my fingers to install a mag catch.

If your button won't go in any farther though, I don't know what to tell ya, like I said earlier, someone needs to start the plastic lower butthurt thread, because this is gonna be epic with all the lego lowers getting snapped up by noobs. Couldn't hardly give those things away prior to the panic.

Hmm, so the mag catch won't be flush to the button after I screw it on?

Okay, under normal circumstances, the mag catch threaded end should be close to flush with the button it's screwed into, doesn't have to be perfectly flush, but that's the general rule.

ETA: Second look: Did you install your bolt release before you went to install the mag catch? That's gonna make it even more of a pain, you will have to push that mag catch in deep now as installing the bolt release sticks out further once installed than just the ears do.

You did didn't you, trigger too huh?

I am a little uncomfortable because I cant even get it to a point where the button is recessed into the lower...

Here's what mine looks like:

http://img834.imageshack.us/img834/6690/img07871.jpg

I don't have that issue with my New Frontier lower.  The mag release button was preety snug but it was fine when I lightly sanded the catch with 240 grit sandpaper.  I would strongly recommend against sanding your lower..just sayin.

Lulz.  That was the first thing that came to mind.

It usually isn't...unless you really press.  I just try to get the threaded screw almost even with the bottom when you look at the button.

Repost from here.
http://www.ar15.com/forums/t_3_4/599903_New_Frontier_Armory_Poly_Lower_Review__56K_Stay_Away__OK__.html

Kane

Well gents, its done. My only other issue is that the Magpul stock is beyond tight. I have to grab it and pull with a ton of pressure to get it to budge....any ideas?

As for that quote, he hit the nail on the head! Take down pins where a bitch to get in (and out). I can really even do it by hand. Never thought of the scissors...oh well, its sitting just below the lip so its fine.

Did you make sure you got the Magpul stock the correct size for the buffer tube? The "completed" NFA Polymer lowers come from the factory with a commercial diameter tube - larger in diameter than the mil-spec one.  Magpul makes stocks in both sizes,  I would start by checking to see that they are matched correctly first.

First builds are fun and there is a learning curve.  Mine was in the mid 80s with a Sendra Corp lower.  Everybody is new to this at some point.  Enjoy.

From a post a few months ago, the op stated that the receiver extension was actually more of a half breed. Not either one but closer to an airsoft tube. He ended up changing out the whole thing to get his stock to fit properly. Can't find the post right now.

Thanks for the post and update on the NFA lower info. I just purchased a couple for my first build's really looking forward to this. Want to be able to get what I can here in NY State.

Any suggestions on a Parts kit to get for NFA lower that will work well. I did not see the answer if there was or was no
Also any other trouble shooting steps or hints or tricks is helpful.

Thank you much Everyone

Just finished doing two NFA stripped lowers, both with RRA LPK's.  Observations are as follows.  The Mag Release cutouts are snug, the button wont depress any further then flush with the receiver and the "L" piece on the other side initially would not fit in the cutout until I filed down some material.  Its not an LPK issue as I have 3 different LPKs from 3 different mfg's and they all were a tight fit.  The Mag button hole appears to be undersized so I took a dremmel to it and that allowed me to sink it a little deeper and turn the mag release screw.  Still not flush with the top of the button as is recommended in most guides but it was "good enough".

Aside from that i found the rest of the build to go fairly smooth until i got to the safety selector switch.  That was snug going through both holes in the receiver and when I installed the detent, spring, and grip you cannot discern that noticeable "click" between safe and fire.  I'm still not sure if its because the selector itself is too tight or pushed too far in.  I know based on my military experience you should be able to easily move the selector with just your thumb...and this is difficult on the NFA lower. If anyone has any thoughts on this I'm all ears.

Aside from those two issues, the build was straight forward...it was my first and the things I thought would give me problems (Bolt Catch & Pivot Pin) did not.  Will provide final thoughts once I've had a chance to do a full function check and test fire.

Thought this as well. I thought you bought a factory SBR and the lower was screwed up or something, that would suck.

I now see that its a plastic lower, which sucks as well

In all seriousness OP, glad you got it fixed and take it easy on the take down pin/receiver extension area on that lower.

I posted about this already. Thread

The mag release well has a little shelf in it causing the button to bottom out. I just dremeled it out and the button installed just fine. Also the take down pin hole and safety spring holes may need a drill bit run through them. I can't remember the sizes and I am not home or I would post them.  I am new to the poly lowers but they seem tight. Maybe on purpose I don't know. I know my Aero upper lugs needed to be reamed out as well. RRA LPK takedown pins would not go through. Same thing. I took a drill bit and reamed it out. I don't use a drill I just use the bit and a pair of vise grips.

I have swapped mine out to milspec tubes I to put my Magpul furniture on, so I haven't measured but assumed it was commercial - good to know.

Question on the NFA Lower

I was able to get in the Mag release button used a dremel as it was very snug at first.
Using a PSA LPK no issues just a little dremeling to do here and there
Was able to get the magazine release in 4 maybe 5 turns however when testing it i find the magazine seems to come out easy even with a little pull on the end.

Is this normal for this to do that
If not is it easy for me to fix

This is what I have been noticing as well.

The mag catch and the safety not "clicking" when going into fire position.

The mag catch is a main concern. If I can get that worked out than I may like these. Otherwise will sell them and move on.

You may have to file the other side where the catch sits. My button is only on about half-way and the mags seems to click in and release fine.