80% Polyer ar lowers

[Clippyclip]

Does anyone have experience with 80% ar polymer lowers (easy to make, reliability, durability, etc)? Want to build a fix mag one (since its fixed mag I would rather it be cheap). Stripped fixed mag receivers have insane prices and can't be sold to fid. Or should I get a jig for the price of a stripped lower ($200) then make a fixed mag aluminum receiver? Or should I do something else?

Also how hard is it to finish a polymer lower compared to an aluminum one? If I get an aluminum jig it would be the Easy Jig.

 

[ReluctantDecoy]

Does anyone have experience with 80% ar polymer lowers (easy to make, reliability, durability, etc)? Want to build a fix mag one (since its fixed mag I would rather it be cheap). Stripped fixed mag receivers have insane prices and can't be sold to fid. Or should I get a jig for the price of a stripped lower ($200) then make a fixed mag aluminum receiver? Or should I do something else?

Also how hard is it to finish a polymer lower compared to an aluminum one? If I get an aluminum jig it would be the Easy Jig.

Darkstorm sells fixed billet lowers for $189. Not exactly cheap, but only $20. more than their standard billet lowers, so at least the price isn't just a compliance gouge. They don't seem to have fixed in the cheaper forged models. Could be how it is fixed.

I've seen their completes in MA stores as compliant models, so I assume these would be ok to transfer if you can't find them as just lowers in MA stores.

DSI DS-15 Stripped Billet Fixed Magazine Lower Receiver Black -FXL-BLK

DSI DS-15 Stripped Billet Fixed Magazine Lower Receiver Black -FXL-BLK $189.95

www.dark-storm.com

 

[Clippyclip]

Darkstorm sells fixed billet lowers for $189. Not exactly cheap, but only $20. more than their standard billet lowers, so at least the price isn't just a compliance gouge. They don't seem to have fixed in the cheaper forged models. Could be how it is fixed.

I've seen their completes in MA stores as compliant models, so I assume these would be ok to transfer if you can't find them as just lowers in MA stores.

They will NOT sell stripped lowers to fids, only complete rifles, since the stripped lower can be registered as a pistol.

I ONLY need the lower as I got an upper and lpk and etc. For that price I would just buy a jig and finish lowers (which I have). The fixed lower is only gonna be used until I move out of mass or upgrade to an ltc (which will take almost 2 years including monstrous turn around time), whichever happens first.

 

[ReluctantDecoy]

They will NOT sell stripped lowers to fids, only complete rifles, since the stripped lower can be registered as a pistol.

I ONLY need the lower as I got an upper and lpk and etc. For that price I would just buy a jig and finish lowers (which I have). The fixed lower is only gonna be used until I move out of mass or upgrade to an ltc (which will take almost 2 years including monstrous turn around time), whichever happens first.

Not a great example because of the obvious price hike, but they do pop up on MA from time to time.

DARK STORM INDUSTRIES DS-10 FIXED MAG RECEIVER – The Gun Parlor

thegunparlor.com

 

[peterk123]

Can any of these fixed mag lowers ever be unpinned or unfixed? It would be nice to be able to convert it a normal gun on the day some of us may be fortunate enough to get out of this state.

 

[Clippyclip]

Not a great example because of the obvious price hike, but they do pop up on MA from time to time.

DARK STORM INDUSTRIES DS-10 FIXED MAG RECEIVER – The Gun Parlor

thegunparlor.com

That's an ar10 lower. But I meant that NO place sells a stripped lower to an FiD not just DSI and JCarms and etc. Unless it was registered as a rifle previously (which is about never), otherwise it is just a blank slate which can be a pistol or rifle. Best bet would be a used one that has been stripped and that has yet to come up. So my best bet is building one from 80%.

Thanks for trying to help though! I do appreciate it.

 

[ReluctantDecoy]

That's an ar10 lower. But I meant that NO place sells a stripped lower to an FiD not just DSI and JCarms and etc. Unless it was registered as a rifle previously (which is about never), otherwise it is just a blank slate which can be a pistol or rifle. Best bet would be a used one that has been stripped and that has yet to come up. So my best bet is building one from 80%.

Thanks for trying to help though! I do appreciate it.

I stand corrected. Still, I swear I've seen those somewhere in MA as lowers. I'll hit up this thread if I can remember where I saw them.

 

[greencobra]

Does anyone have experience with 80% ar polymer lowers

i do. i have a polymer 80 that came with the jig for 90 bucks several years go. it was no different than doing an aluminum 80%, they supplied all the tooling, also. i've only got several thousand rounds thru it, just seeing if it functioned and would hold up. it did. it's basicly put away now in the bunker cause it's my "if they pry my gun from my cold, dead hands" gun, i'll still have it. one thing they didn't tell me and i don't know if it's all polymer lowers, the walls of the receiver are thicker than metal lowers. you need a longer rear take down pin which polymer 80 sells on their site. see the photo. i'm using the regular pin with no ill effect, but...., you can see the shadow in the hole where the pin didn't come all the way thru.

 

[SKumar]

i do. i have a polymer 80 that came with the jig for 90 bucks several years go. it was no different than doing an aluminum 80%, they supplied all the tooling, also. i've only got several thousand rounds thru it, just seeing if it functioned and would hold up. it did. it's basicly put away now in the bunker cause it's my "if they pry my gun from my cold, dead hands" gun, i'll still have it. one thing they didn't tell me and i don't know if it's all polymer lowers, the walls of the receiver are thicker than metal lowers. you need a longer rear take down pin which polymer 80 sells on their site. see the photo. i'm using the regular pin with no ill effect, but...., you can see the shadow in the hole where the pin didn't come all the way thru.

View attachment 337521

I've always wondered how those polymer AR lowers would hold up. I imagine the BCG is just slamming against the rear action where the buffer inserts. Good to know it works for you. Must be lightweight as hell.

 

[greencobra]

I imagine the BCG is just slamming against the rear action where the buffer inserts.

not really. the bcg doesn't touch the polymer lower, just pushes the buffer back into the metal tube. the polymer lower is actually pretty beefy and strong...much to my surprise. honestly, i didn't expect it to be as robust as it is. it was a fun experiment/project. when i take it to the range people are pretty surprised it's a polymer build.

 

[Clippyclip]

Can any of these fixed mag lowers ever be unpinned or unfixed? It would be nice to be able to convert it a normal gun on the day some of us may be fortunate enough to get out of this state.

Converting commercial fixed mag lowers would require destroying the pieces that hold in the mag release, don't even bother with commercial fixed mags if you care about mag removal, they are more "fixed" than what is needed to be legal in mass. More on that in the third paragraph. If you move to a free state stripped lowers are extremely cheap and you can mount your fixed ar components (upper, stock, grip, lower parts, etc) to a $50 stripped lower.

If you have an LTC in MA you can make a normal AR15 style rifle from a 80% lower legally. There is nothing in the MGL (ACTUAL law) that says you can't and it's been touched on 1000 times that the enforcement notice has 0 legal standing. You could also get a .22lr registered ar15 if you do want to abide by the EN and change the caliber as changing caliber doesn't require re-registering or does the EN say that makes it an "assault weapon". Or you could break the bank and get a "grandfathered" ar lower that pop up in the NES classifieds daily.

If you really want a fixed mag ar for any reason (dont have LTC, pistol build, worry of federal ban, or want post-ban full features), and really want to be able to convert it back to normal ar after have moved to free state (especially if it's an NFA item) OR want to be able to put in a different caliber magazine while in mass (and stay fixed), there is hope! You can have a gun that is legally a low capacity gun but still have the mag technically removable without destruction of gun parts (EG using power tools to release the mag catch that you need to do on commercial fixed mags). A gun is only "readily modifiable" to accept a large-capacity feeding device (lcfd) if you can insert a lcfd with only immediate alteration of the weapon (basically either pressing mag release or bullet button). However, a gun is still low capacity if you can't immediately alter. The SKS you can be converted to be capable of accepting a lcfd if you simply take out the fixed mag, which is only a simple 3 step process (remove trigger group, remove fixed mag, insert trigger group, done), but the SKS is still considered low-capacity as that is not immediate alteration of the gun. If a fixed mag ar is put together correctly its also basically a 3-4 step process.

For a fixed mag AR to not be able to be immediately altered to accept a lcfd ("readily modifiable"), you'll need a stripped non-registered lower (not a gun by MA law, so legal to not register) or have one you built yourself, which you'll need to turn into a functioning lower, and then you'll need the Cross-Armory fixed mag kit, and a mag of your choice (any caliber). Simply follow the instructions except DO NOT PUT THE PLASTIC PLUG IN! Just the mag, mag catch, nut and screw, and you're good to go! Really that's it, go register it! To alter the gun to accept a lcfd you would need to take out the screw, then nut, mag catch, then mag, meaning it can't be immediately altered to accept a lcfd. If you move to a free state you can remove the kit and have a normal ar (of course you need a normal mag catch, spring, and button to replace the kit). If you are in MA and want a different mag because wanting a new caliber or simply new mag type, just temporarily remove the kit and mag (when it is removed the gun cannot function normally), and reinstall it with the new mag!

501 CMR 7.02:
"Capable of Accepting a Large Capacity Feeding Device means any firearm, rifle or shotgun in which a large capacity feeding device, as defined by M.G.L. c. 140, § 121, is capable of being used without alteration of the weapon; provided, however, that said feeding device is fully or partially inserted into the weapon or attached thereto, or is under the direct control of a person who also has direct control of a weapon capable of accepting said feeding device. "

"Readily Modifiable to Accept a Large Capacity Feeding Device means any firearm, rifle or shotgun immediately capable of being altered so as to accept a large capacity feeding device as defined in M.G.L. c. 140, § 121; provided, however, that said feeding device is fully or partially inserted into the weapon or attached thereto, or is under the direct control of a person who also has direct control of a weapon capable of accepting said feeding device. "

https://www.mass.gov/files/documents/2017/09/29/501cmr7.pdf

Of course it is illegal to convert your gun to a large-capacity gun while in MA so don't do that.

THIS SAME METHOD WORKS WITH AR10 TYPE RIFLES

 

[Clippyclip]

i do. i have a polymer 80 that came with the jig for 90 bucks several years go. it was no different than doing an aluminum 80%, they supplied all the tooling, also. i've only got several thousand rounds thru it, just seeing if it functioned and would hold up. it did. it's basicly put away now in the bunker cause it's my "if they pry my gun from my cold, dead hands" gun, i'll still have it. one thing they didn't tell me and i don't know if it's all polymer lowers, the walls of the receiver are thicker than metal lowers. you need a longer rear take down pin which polymer 80 sells on their site. see the photo. i'm using the regular pin with no ill effect, but...., you can see the shadow in the hole where the pin didn't come all the way thru.

Thanks for the info! Do you feel the polymer lower makes the rifle noticeably lighter? I am transitioning to an ar from an sks, mostly because the weight of the sks is far too much for me to be comfortable with especially with its horrible ergonomics! So want to try to save as much weight on the ar as possible.... considering SBRing it too to make it far less front heavy, even though that will be a bit of a pain.

 

[greencobra]

Do you feel the polymer lower makes the rifle noticeably lighter?

but it's only a few ounces lighter. noticeably?...in a rifle configuration, not really. as a sbr, that's probably when you'd notice and appreciate the several ounce weight reduction more.

 

[peterk123]

Converting commercial fixed mag lowers would require destroying the pieces that hold in the mag release, don't even bother with commercial fixed mags if you care about mag removal, they are more "fixed" than what is needed to be legal in mass. More on that in the third paragraph. If you move to a free state stripped lowers are extremely cheap and you can mount your fixed ar components (upper, stock, grip, lower parts, etc) to a $50 stripped lower.

If you have an LTC in MA you can make a normal AR15 style rifle from a 80% lower legally. There is nothing in the MGL (ACTUAL law) that says you can't and it's been touched on 1000 times that the enforcement notice has 0 legal standing. You could also get a .22lr registered ar15 if you do want to abide by the EN and change the caliber as changing caliber doesn't require re-registering or does the EN say that makes it an "assault weapon". Or you could break the bank and get a "grandfathered" ar lower that pop up in the NES classifieds daily.

If you really want a fixed mag ar for any reason (dont have LTC, pistol build, worry of federal ban, or want post-ban full features), and really want to be able to convert it back to normal ar after have moved to free state (especially if it's an NFA item) OR want to be able to put in a different caliber magazine while in mass (and stay fixed), there is hope! You can have a gun that is legally a low capacity gun but still have the mag technically removable without destruction of gun parts (EG using power tools to release the mag catch that you need to do on commercial fixed mags). A gun is only "readily modifiable" to accept a large-capacity feeding device (lcfd) if you can insert a lcfd with only immediate alteration of the weapon (basically either pressing mag release or bullet button). However, a gun is still low capacity if you can't immediately alter. The SKS you can be converted to be capable of accepting a lcfd if you simply take out the fixed mag, which is only a simple 3 step process (remove trigger group, remove fixed mag, insert trigger group, done), but the SKS is still considered low-capacity as that is not immediate alteration of the gun. If a fixed mag ar is put together correctly its also basically a 3-4 step process.

For a fixed mag AR to not be able to be immediately altered to accept a lcfd ("readily modifiable"), you'll need a stripped non-registered lower (not a gun by MA law, so legal to not register) or have one you built yourself, which you'll need to turn into a functioning lower, and then you'll need the Cross-Armory fixed mag kit, and a mag of your choice (any caliber). Simply follow the instructions except DO NOT PUT THE PLASTIC PLUG IN! Just the mag, mag catch, nut and screw, and you're good to go! Really that's it, go register it! To alter the gun to accept a lcfd you would need to take out the screw, then nut, mag catch, then mag, meaning it can't be immediately altered to accept a lcfd. If you move to a free state you can remove the kit and have a normal ar (of course you need a normal mag catch, spring, and button to replace the kit). If you are in MA and want a different mag because wanting a new caliber or simply new mag type, just temporarily remove the kit and mag (when it is removed the gun cannot function normally), and reinstall it with the new mag!

501 CMR 7.02:
"Capable of Accepting a Large Capacity Feeding Device means any firearm, rifle or shotgun in which a large capacity feeding device, as defined by M.G.L. c. 140, § 121, is capable of being used without alteration of the weapon; provided, however, that said feeding device is fully or partially inserted into the weapon or attached thereto, or is under the direct control of a person who also has direct control of a weapon capable of accepting said feeding device. "

"Readily Modifiable to Accept a Large Capacity Feeding Device means any firearm, rifle or shotgun immediately capable of being altered so as to accept a large capacity feeding device as defined in M.G.L. c. 140, § 121; provided, however, that said feeding device is fully or partially inserted into the weapon or attached thereto, or is under the direct control of a person who also has direct control of a weapon capable of accepting said feeding device. "

https://www.mass.gov/files/documents/2017/09/29/501cmr7.pdf

Of course it is illegal to convert your gun to a large-capacity gun while in MA so don't do that.

THIS SAME METHOD WORKS WITH AR10 TYPE RIFLES

Wow, and thank you. I will need to re-read this many times but that is one of the best explanations I have ever read. Pete

 

[92G]

@Clippyclip

avoid polymer lower
start with 6061, not 7075
5D jig

you're welcome

 

[Boris]

but it's only a few ounces lighter. noticeably?...in a rifle configuration, not really. as a sbr, that's probably when you'd notice and appreciate the several ounce weight reduction more.

Polymers are 1/3 of the weight of aluminum, so it may be helpful as MA pistol that has to stay under 30oz

There are polymers with steel reinforced rear buffer end, and they are very strong.

I've made steel reinforced plastic lower that is still working after 1k rounds.

 

[Wildweasel]

(iv) a manufactured weight of 50 ounces or more when the pistol is unloaded is the way the law is written. so stay under 50oz.

MA Assault Weapons Ban "AWB" FAQ

Background: What is the MA AWB? The "Assault Weapons" ban in MA is almost a verbatim version of the Federal AWB that existed from 1994 - 2004. This is how it is currently encoded in MA law: http://www.malegislature.gov/Laws/GeneralLaws/PartI/TitleXX/Chapter140/Section121 The "Assault...

www.northeastshooters.com

 

[teamRR]

I saw a grandfathered MA lower recently for $600. Know nothing about MA law but if that is all it takes to build a fairly normal AR I think the $$ would be well worth it.

 

[92G]

(iv) a manufactured weight of 50 ounces or more when the pistol is unloaded is the way the law is written. so stay under 50oz.

MA Assault Weapons Ban "AWB" FAQ

Background: What is the MA AWB? The "Assault Weapons" ban in MA is almost a verbatim version of the Federal AWB that existed from 1994 - 2004. This is how it is currently encoded in MA law: http://www.malegislature.gov/Laws/GeneralLaws/PartI/TitleXX/Chapter140/Section121 The "Assault...

www.northeastshooters.com

waiting for @drgrant to crack his jokes about how sub 50 oz "pistol" requires oven mitt to avoid burning fingers off

 

[Boris]

I saw a grandfathered MA lower recently for $600. Know nothing about MA law but if that is all it takes to build a fairly normal AR I think the $$ would be well worth it.

I doubt it. Maura's edict is a fear tactics that no one wants to test, so fear surplus is only worth as much as people are scared.

 

[Clippyclip]

I saw a grandfathered MA lower recently for $600. Know nothing about MA law but if that is all it takes to build a fairly normal AR I think the $$ would be well worth it.

Pre-Healey is just a marketing term for overpriced lowers now lol. Just get a 80% lower and a jig for half that price (jig is reusable) or a .22lr ar and just stick a .223 upper onto it and be done with it. It's not illegal. I'm not afraid of a bullshit enforcement notice. I'm only building a fixed mag ar because I have a Fid and the ACTUAL law (MGL) says you cannot own semi autos that can switch mags quickly on a Fid.

Online ammo retailers got an enforcement notice, some ignored it, and nothing happened to those who ignored it because BS enforcement notices have 0 legal standing and Healey knows it.

 

[teamRR]

I guess. The point of a fixed mag AR is way lost on me..

So I guess even though they are mass ok, even a mini 14 you can't own on an FID ?

 

[Clippyclip]

I guess. The point of a fixed mag AR is way lost on me..

So I guess even though they are mass ok, even a mini 14 you can't own on an FID ?

Mini 14 is a no go for a Fid. The mini 14 meets the criteria of "readily modifiable" because it can be immediately altered to accept high-cap mags (immediately altered means pressing a mag release or bullet button).

Fixed mag ars purpose is really only for Fids, people who want to build an ar pistol (having a detachable mag outside the grip is an "assault weapon" feature, so is being over 50oz and the ar will definitely outweigh that, and you can only have 1 AW feature per gun, so need a fixed mag), and people who want a post ban ar with all the accessories and think it being fixed is a good compromise.

Edit:
Also by the letter of the law, a Ruger 10/22 is also a no go for a Fid as it meets the criteria of "readily modifiable". Though it is generally considered low-capacity by people because it is not on the hich-cap gun list (like some other .22lr semi autos with detachable mags). But a gun doesn't need to be on the list to be considered high-cap. You most likely wont get jammed up for having a 10/22 on a Fid though, a mini 14, not so much. Our laws suck, I know.

 

[akma]

James Madison Tactical has reinforced polymer lowers.