Poly AR lower

[La Dano]

Just picked up a new poly AR lower, any feelings about them? My 1st AR build also.

Thanx

[MtGun44]

What brand. Plum Crazy has some detractors. I have used a few different
ones that functioned perfectly.

Bill

[nhrifle]

As long as all the parts fit where they are supposed to and function safely, the lower receiver is just a carrier for the fire control group. It does not endure any stress during firing, as al that is contained within the barrel/bolt and transferred straight back through the buffer tube to the buttstock. If it is good quality, you won't have any problem.

[xacex]

I have a few of the New Frontier lowers, and have had them side by side with the ATI lowers. I like the composite that they make the New Frontiers out of. Seems like it should hold up better to abuse than what the ATI's can handle. They have a vid of the guys shooting 458 socom with a New Frontier, and tossing the rifle back and forth into the dirt. I have a 300 blackout pistol built on one, and have no complaints. Guaranteed for life, and it is transferable. What more could you want? My forged lowers don't come with that guarantee.

[highbrow]

I picked up an ATI poly lower about 6 month ago. 600rounds through it so far with no problems, but I did not throw it down the driveway.

[La Dano]

I was told I wouldn't be disappointed, I'm not gonna throw it down the driveway either, hehe. I think my wife is gonna try and take it from me. She's been wanting one for a couple years now.

[HATCH]

The only thing i read about polymer lowers is some are rated only for 223/22lr

[Moonie]

I have a plum crazy lower, works just fine on both my 6.8 SPC upper and my 300AAC upper.

[xacex]

The only thing i read about polymer lowers is some are rated only for 223/22lr
That would be the case with the ATI's.

[La Dano]

I got the FMK's.
I guess it's gonna be a while before I can get the rest of my parts.

[Artful]

I've used cavalry arms for years no problems.

Now made by
http://www.gwacsarmory.com/cav-15-mkii.html
Not indestructible
http://www.arizonashooting.com/v3/viewtopic.php?f=3&t=133214

but neither is the Aluminum version

[MtGun44]

Not the lower I would choose for bayonet fighting, but I hardly ever do any of that.

:bigsmyl2:

Bill

[La Dano]

Hope I don't run out of boolits to use a bayonet. Hehehe
I would like to try some cast in it one day. Any suggestions?

[Boz330]

Hope I don't run out of boolits to use a bayonet. Hehehe
I would like to try some cast in it one day. Any suggestions?

Reminds me of a DI telling us in bayonet training one day that occasionally a bayonet will get stuck and you may have to shoot it loose. I thought, to myself, that if I have bullets left I'm not going to be sticking anybody with a dull knife.

Bob

[La Dano]

I definitely see you point Bob. Hehe

[Screwbolts]

I have a Plum Crazy Lower that has had more than 6000 rounds fired from 3 different 5.56 uppers. It functions perfectly and is still as tight as new. I also have had the same GREAT experience with the New Frontiers. over 2500 rounds from one of them.

I currently have a New Frontier equipped with a Exile Machine, Hammerhead grip and Ace entry length butt stock. this combination has seen 400+ rounds in the last 2 weeks. I am liking it very much. This configuration is actually easier for my wife to shoot.

[La Dano]

SB, you make me jealous. I'll be glad when I finally come up with a upper.

[fishnbob]

I just started putting a LPK in a New Frontier. The first step was a pisser! The simple Mag Catch/Release. I had to recut both the Magazine Catch side and the Magazine Catch Button side to enable the catch to thread and the magazine catch wouldn't seat deep enough to lock the mag.
Neither part would go in the recess at all. Thank God for a Dremel tool, now If my eyes were good enough to see what I'm doing, I might make it. If I run into any more of that I'm going to see about sending it back. I expected a little burr removal but it looks like the hole is drilled off. It works, but it ain't slick like my other AR. Anybody else having trouble with the cutouts?

[La Dano]

Well a little update on my end. I finally got a LPK in 1 of my poly lowers, trigger pins were a little loose and I had to drive the rear pin in my upper. The upper came off my wife's Wyndam Weaponary. Now that AR shoots 1 hole groups with my loads at 75yds, very nice trigger as well. So I swapped the upper to my poly lower and ran 200rds through it. Hardly a pie plate group now. So Thur I was telling my buddy about the groups, he said to bring it back and he would check it out. Come to find out the 2 poly lowers were just a little off, he offered to swap them out for Red Jacket 6061 lowers so I jumped on them. I'm putting the Wyndam back just the way it was, it shoots awesome with 3 different loads I have. Still want to try some cast with it.

[Tom-ADC]

I bought the New Frontier poly lower and will start assembly this week, I did test fit a couple of parts and find it to be very tight.
With luck I should be able to test fire it next week.
This is my first AR build hope it goes good.

[fishnbob]

Well a little update on my end. I finally got a LPK in 1 of my poly lowers, trigger pins were a little loose and I had to drive the rear pin in my upper. The upper came off my wife's Wyndam Weaponary. Now that AR shoots 1 hole groups with my loads at 75yds, very nice trigger as well. So I swapped the upper to my poly lower and ran 200rds through it. Hardly a pie plate group now. So Thur I was telling my buddy about the groups, he said to bring it back and he would check it out. Come to find out the 2 poly lowers were just a little off, he offered to swap them out for Red Jacket 6061 lowers so I jumped on them. I'm putting the Wyndam back just the way it was, it shoots awesome with 3 different loads I have. Still want to try some cast with it.

I had to drive the rear pin in also and it locked up and wouldn't function so I had to remove spring & detent pin to get it out. When I got the pin to function it went from too tight to too loose and now it will vibrate out. Anybody got any suggestions?

[bhop]

only thing ive heard is not to release hammer without upper attached as this may break it

[fishnbob]

I'm about to take a hammer to mine. Nothing has fit, everything had to be fitted, the holes for the pivot pin and the take down pin didn't fit the pins. After getting them in and functional, the uppers I tried wouldn't line up and didn't drop in the lower with the pins backed out. The mag well had to be ground out with a Dremel tool and will accept 30 rd mags but not 10 rd mags, which by the way work fine in my other AR's. The guy I bought it from here said he has sold over 150 with no problems. How 'bout it guys, am I the only one having trouble?

[Tom-ADC]

Just finished mine today used a PSA lower kit, as noted by some everything was a very tight fit, holes a tick undersize & the slots for the magazine catch had to be opened a little so the part would fit same for the release button.
I can't say about the magazine well yet thought I had some magazines but they are for my mini 14 and don't fit. I have a couple on the way so I'll see. Over all I'm not 100% happy yet but maybe when I shoot it next week.

http://pic20.picturetrail.com/VOL174/1021972/3058943/406621520.jpg

[xacex]

Fishnbob, I had a couple that were a little more work to put the LPK in due to the holes being undersized slightly. Once all fitted up everything was as tight as I like it to be. I didn't have a problem with the mag well like you are. You should contact New frontier about that issue, and see if they will sent out another one until you are happy. Let us know how it goes with customer service with the lifetime warranty if you decide to do that. I am curious how they treat you. I have heard that they are A o.k. on that side, but that was from the third person. So far I have no complaint with mine.

[Tom-ADC]

I've done all the function checks per the Brownells videos but until my magazines show up I can't do a cycle check I have 10 of the plastic training bullets to do this with. It kinds of grows on you if it shoots okay and no reason it shouldn't I'll just figure since its together its good to go.
BTW this is now my Diane Feinstein tribute rifle, I'd never owned one if it hadn't been for her.

[Stash714]

You have to use plastic bullets in Cali?http://i10.photobucket.com/albums/a125/Idge0/funny/60burst.gif (http://s10.photobucket.com/user/Idge0/media/funny/60burst.gif.html)

Can you use any size mags in Cali now?

It looks good. There's not that much stress on the reciever anyway. As long as your not in combat.

[fishnbob]

Fishnbob, I had a couple that were a little more work to put the LPK in due to the holes being undersized slightly. Once all fitted up everything was as tight as I like it to be. I didn't have a problem with the mag well like you are. You should contact New frontier about that issue, and see if they will sent out another one until you are happy. Let us know how it goes with customer service with the lifetime warranty if you decide to do that. I am curious how they treat you. I have heard that they are A o.k. on that side, but that was from the third person. So far I have no complaint with mine.

The dealer that I bought it from emailed me and told me he has talked to New Frontier and they would replace it if I send the other back. Then I get an email from New Frontier telling me to return it with the LPK in it along with the brand of upper and some of the mags I was having trouble getting to lock up. In the meantime, I have fixed the mag lock up problem and I anticipated having to return it for a replacement so I removed the LPK kit and in removing the rear pivot pin the detent broke out the edge of the hole in the polymer lower. Dammit! I have two uppers backordered and I plan on taking the 1st one that becomes available, so I don't know which it will be. I am 0.020" away from getting the upper off one of my factory AR's to fit. If I send it back and they replace it with one exactly like the one I have, then I have to start over inletting & fitting parts. I didn't have the luxury of opening up the mag catch & button, I had to mill it out deeper as well as bigger to get the two parts to thread up and function. Everything I went to put in, I ran into problems that a file and sandpaper would not fix. It was Dremel & drill. The problem with that is my eyes don't see black plastic in a dark hole like they used to. I can't get enough light in there with my big head trying to peep in the button hole to see how far I need to go. Everybody keeps telling me about the disparity in "Mil-Specs". I thought the idea was to make everything the same so parts would be interchangeable. I don't know what to do. Fix up what I have or try to negotiate warranty repair or replacement. NF sent me an answer to my email that suggested repair if I know what upper I will be using and like I said I don't know yet. What would you do? I'm open for suggestions or advice.

[Doc_Stihl]

I had problems fitting my mag catch. The slot appeared to be tapered. Rather than deal with cutting up the lower I ground my mag catch to fit. My pivot pin hole was undersized. My take down pin hole was tight and the detent hole had junk in it. I had some gentle filing and cleaning up to get it sharp edge free.
I'd buy another one if I had the need to make a lightweight rifle. The work to get it cleaned up and assembled wasn't excessive.

[xacex]

Fishnbob, I would put your parts in a bag along with a note that you took them out because there was an issue, and you were thinking of using another lower. Let them know that the lower was damaged taking out the detent pin as well. Put all the parts requested in a box, and ship it out to them. You will most likely get a new lower all fitted up with the parts in it, and the upper attached. This helps them figure out what the issue is, and make adjustments to the mold, or equipment they are using for more manufactures. The problem I have found with any fiberglass composite that is molded is that after a while the parts begin to come out out of spec due to mold use and shrinkage. I do not know what type of equipment they are using, but it may be possible that they got a mold that was slightly out of spec during the rush to get these out. A lower is a high precision piece, and even slightly off can cause a lot of headaches.

[Tom-ADC]

You have to use plastic bullets in Cali?http://i10.photobucket.com/albums/a125/Idge0/funny/60burst.gif (http://s10.photobucket.com/user/Idge0/media/funny/60burst.gif.html)

Can you use any size mags in Cali now?

It looks good. There's not that much stress on the reciever anyway. As long as your not in combat.

No not yet, use them for function check, magazine have 10 round limit and we have no mag reales button, we have a bullet button lot of folks drill a hole in a plastic bullet and use it to push the bullet button to drop the magazine.
I'm still toying with buying a aluminum lower but not until I shoot this one.

[oldsgm]

I just put another New Frontier lower together, I had the same problem with the tight mag release button, but minor polishing with a dremel took care of it. Other than that, no fitting problems. This makes about 6 of them I have assembled since last fall (I build guns for other people), and this was the first problem I had. I have also had problems with metal lowers recently also. It seems that in the rush to meet the demand, quality control on critical dimensions slipped a little. Still and all, a good receiver.

[lonewelder]

I bought a complete new frontier lower way before the current rush and have not had a lick of trouble.Upper to lower fit is tight,better than average trigger and mags drop free.Maybe the QC has gone down to try to keep up with demand.Mabye if I tried putting a mil-spec LPK in it I would have the same trouble,but the way it works now I'll leave it.Sorry to hear about all the problems.

[drsfmd]

Another +1 for New Frontier. I know several guys using them. Like "regular" lowers, the polymer ones vary in quality from manufacturer to manufacturer. Just do your homework before you buy...

[Tom-ADC]

Magazines and snap caps showed up today, they fit without a problem and release okay. Now to get to the range for a live ammo function check.

[fishnbob]

The range function check on my AR build was a let down to say the least. I pull the trigger and it goes bang. Great! I release the trigger and it goes bang. #@%$&#**! On the bright side, if the DOUBLE TAP is your thing, you have a leg up on the competition. The bad thing is the state police & county sheriffs department firing range is within hearing of me.

[MtGun44]

No probs with New Frontier. Works perfectly.

Bill

[fishnbob]

I got it boxed up and ready to mail back this morning. I'll let you know how their Lifetime Warranty works. Their email said "We want to take care of you".

BTW Bill, did yours require much inletting & fitting and did your upper drop in with a snug fit?

[Tom-ADC]

fishnbob, I used a Del-Tron upper the front pin went in snug and the rear tight. But the upper went right on without touching anything. The main thing I had too tweak was the magazine catch & release button.

[fishnbob]

fishnbob, I used a Del-Tron upper the front pin went in snug and the rear tight. But the upper went right on without touching anything. The main thing I had too tweak was the magazine catch & release button.

That's why I didn't want to open up the rear slot to accept an upper that I wasn't going to use in that receiver. One of the two that I have on backorder would be used but I can't be sure of the dimension until I get it. I want it to fit snugly without slop which I'm sure it will accumulate later on with use. I also wonder if the trigger pin holes are the source of the double fire? I hear a lot of guys over on AR15.com don't give polys a good recommendation.

[Tom-ADC]

From what I've read the New frontier is a great lower, there are a couple that got bad reviews but not New Frontier, also from what I've read their customer service is top notch.
My trigger & hammer pins where snug but a small brass hammer tapped them in with no problems. I've function checked it using snap caps and will soon shoot it. I don't have any concerns that it will not function properly.

[xacex]

Well, over on AR15.com they don't like it if it does not have a designer tag like YHM,Larue,LARS,Troy,DD, or Midwest Industries. They are kind of on the AR snob side of the issue, and just like Glock when it came out there were the naysayers. There are parts out there without those tags that work just fine, but quality control may be a little more of an issue with some. There are several that are made in China as well like GRG or UTG that work just fine for free float rails, but the fellers of on ARF will chuckle at you. Hey, if it works fine and you don't need the (special) tags on your parts go for it. You are still ahead of many of the gun owners out there that would give a left nut for an AR15 right now. These things are not cheap, and you can always upgrade your parts later if you want to be in that crowd. Most likely you will still get oo's, and aw's from your friends and relatives with whatever you put together. It is after-all, a evil black rifle :roll:that everyone has seen on the news, and they will want to shoot it no matter what you put on it.

[fishnbob]

xacex, very well put. My thoughts exactly. I have some very expensive rifles that can't hold a candle to some of my less costlier ones, and I don't have any that have been worn out from use. Frankly, I am buying what I can get, not what I can afford.LOL

[Coyote3]

I have a couple of CavArms lowers that get quite a bit of use. Here's one my wife and daughter enjoy shooting. It usually gets a few second glances at the range.

70963

Now I just need to get a .22 cal. mold, so we can enjoy it even more.

[fishnbob]

I can occasionally get .223's at Walmart but no such luck on .22's. Man, that thing is hot looking Coyote3. You probably are getting 2nd glances that are in fact, LUST!

[MtGun44]

I knew DeWalt made power tools . . . . . . but that is a new one! :bigsmyl2:

[bucklind2]

Just put together my Ar last weekend using a New Frontier lower with the parts kit already installed. All the parts but the springs are polymer and the fit is very tight. I mated it to a DPMS upper and installed a Wilson Combat 16" stainless 7.62x40 barrel. Then installed a Yankee Hill free-floating hand guard to finish it off. I am very pleased with the results and would definitely buy another New Frontier lower. I was able to find one for 109.95 with free shipping. I think it a great deal with a lifetime guarantee. I was a little concerned that the trigger would be subpar, but it has about a 4.5 lb break with no creep. Was pleasantly surprised. If anyone would like to know where to get the lowers for the price I mentioned please send me a PM and I will respond. I don't want to post the info because there is a member selling them here on the forum.

[Moonie]

I have 2 polymer lowers, one Plum Crazy that has put up with my 300 BO and 6.8 SpecII uppers. The New Frontier is new and will be used for a pistol build I believe.

[fishnbob]

Fishnbob, I would put your parts in a bag along with a note that you took them out because there was an issue, and you were thinking of using another lower. Let them know that the lower was damaged taking out the detent pin as well. Put all the parts requested in a box, and ship it out to them. You will most likely get a new lower all fitted up with the parts in it, and the upper attached. This helps them figure out what the issue is, and make adjustments to the mold, or equipment they are using for more manufactures. rush to get these out. A lower is a high precision piece, and even slightly off can cause a lot of headaches.

You sure hit that on the head xacex! I did as you said and I got it back yesterday. The LPK was reinstalled by them and they substituted their hammer & trigger to solve the hammer falling on the trigger release problem. It was a new lower and all is working well. I couldn't be more pleased with their customer service. I will definitely buy another, soon.

Bob

[xacex]

You sure hit that on the head xacex! I did as you said and I got it back yesterday. The LPK was reinstalled by them and they substituted their hammer & trigger to solve the hammer falling on the trigger release problem. It was a new lower and all is working well. I couldn't be more pleased with their customer service. I will definitely buy another, soon.

Bob

I am glad to hear they treated you well. I have no issue with the ones I have( other than feeling funny) but it is good to know I would be taken care of if there was an issue. Time to pin one to the Beowulf upper, and see if they will take it.

[bbailey7821]

Xacex,
Thats my plan as well. I will be checking in next week with a range report. Stay tuned for the John Ross 400g HP Streetsweeper in a Beowulf!

:bigsmyl2:

[fishnbob]

Has anyone out there had trouble with the New Frontier lower using 10 round mags? I've got a couple for hunting & bench rest shooting but the bolt may pick up the first round and not the second. Sometimes it won't feed at all. Both mags work great in my S&W M&P.

[xacex]

Has anyone out there had trouble with the New Frontier lower using 10 round mags? I've got a couple for hunting & bench rest shooting but the bolt may pick up the first round and not the second. Sometimes it won't feed at all. Both mags work great in my S&W M&P.

If you are having an issue with it switch that upper to the M&P lower to see if it still doesn't feed. If it doesn't it most likely is the barrel extension. I polish all the feed ramps on mine now to make them feed anything.

[xacex]

Xacex,
Thats my plan as well. I will be checking in next week with a range report. Stay tuned for the John Ross 400g HP Streetsweeper in a Beowulf!

:bigsmyl2:

Haha! Sounds great! I haven't had a chance to swap one in yet. I did a trigger job on a NFA lower and got the thing down to a few pounds or abouts, but I took too much off the back of the trigger under the safety, and need to weld it up a little or get a new trigger. This is with a metal trigger group, not the NFA group. I had to drill out the pistol grip hole and thread it all the way through because they are not drilled and tapped for trigger work. Don't worry, that part of the trigger I need to weld is not a heat sensitive hardened area, well, as long as I don't heat the whole thing up tacking a bead to the back it will be fine. The other NFA lower I have has the plastic trigger group in it, and frankly I am spoiled with my lowers with the trigger work done so I don't play with it much.

[Tom-ADC]

I just put a Spikes ST-22 upper on my New Frontier poly perfect fit now I need a range trip.

[Tom-ADC]

Spikes ST-22 upper assembly on a NFA lower, PSA LPK.

http://pic20.picturetrail.com/VOL174/1021972/18168454/407270216.jpg