How To Build An AR-15 Lower Receiver

I was cleaning the garage today and I came across a box of old AR parts that I had previously replaced with better parts so I thought why not build and they are lower and show you guys how I do it now if you don't want to build your own you can always go to proxy bit and take up a complete lower there we've got some pretty good prices and frankly it's a lot less work all right so we've separated all of our parts and we're going to start with the magazine catch so get your magazine catch spring your magazine catch and the mag catch button mag release button where you want to comment I'm going to set that guy in there like that drop the spring over the threaded portion give this guy a couple of quick turns alright and then I like to use a five five six dummy round stick that in the hole and rotate now you're going to keep going until that's about flush so we're good right there mag catches installed next up we are going to install the trigger so you triggered your tour to return spring and the sky goes around the pivot point right here that way if you think of it this way it's providing pressure against the bottom of the lower inside the trigger pocket to allow that trigger to return to where it's supposed to so next up we're going to get the disconnect or spring now this is the one that's got the flared end on it one side will be a bit wider than the other just pop that in there and then you get your disc connector and this little cutout right here go and right on top of that spring so that whole assembly drops right in just like that so apply some pressure on the back of the disc connector which is giving lined up take your trigger pin push it right in right the wiggle things around just a touch and there you go you don't need a hammer it should slide in just fine if all the tolerances are correct all right so now for the hammer and on the hammer the spring is kind of orientated like this so when it is in the position and it needs to be when it's in the lower you've got the hoop on the backside of the hammer and these two legs forward how you can test to make sure it's good to go it's kind of set it on a table and you can hold the legs down and got pressure you're good so you can take that set it in there rotate it forward and it'll catch so there's no pin in there right now so you don't want to be too angry with it now kind of put your thumb up there and line the hole up and it's a little bit of a bear so I kind of prefer using a guy's Lee install tool it makes things a little bit easier so what the guys are the install tool everything is all lined up for me and all I do is I take the pin and push it in right behind the tool they use a tool to kind of don't need to actually so it's loose enough where I don't need it so now we have our trigger installed all right so next step is going to be the selector switch so just take that guy let's let the hole flip your lower over and you've got your hole there for the detent drop that in there then you want to grab your spring now you're going to have a couple of different Springs there will be two that are identical and they look like they're a little bit thinner and then when it's a little bit shorter and fatter and that's your selector spring so this is the spring we're going to need this one's for later drop that guy in the hole just like that and then there you go so now we're going to grab our flathead screw and a screwdriver so now if you have a Magpul grip you're going to need an allen key or you can use a screwdriver either ones fine this particular grip is supplied with a flat head style screw so take that guy writer drop it down in there into the hole and get it all lined up so we don't go fight with it on the lower all right so now I've got that screw in place I can take the spring put it back into the recess in the grip slide it back over a little protrusion on the lower and screw this thing down now this shouldn't give you any trouble until it starts to cinch down it takes a bit to get there so something that's common is people will strip these screws out and you don't want to fight with it it should be pretty easy like I'm using two fingers to screw it in now and then we're at the bottom just snug it down and you're good to go so now I'll do a quick function check so it should be safe and then put it on fire and get a reset and all that good stuff and there you go alright so now we're going to use the Bev block and I've got it in my vise to hold the lower receiver in place so once you get it orientated right it locks in there it keeps everything still so I'm going to use a Brownells front pivot pin tool and it's really pretty invaluable after you've lost a couple takedown pin detents but line the holes up stick the spring through then take your detent and that sits in there just like that use the included pusher to push it and then pivot it so it keeps it captive then you just take your pivot pin and push it on through it's that easy alright so I spun the vise around time to get the takedown pin in place and we're going to take the pin insert it into the takedown pin hole we're going to take the detent shove that in the hole in the back of the receiver and then the pin or the the spring rather follows it just like that so rotate it till its captive and then you should hear a click just like that so we're good to go there the next step is going to be threading on the receiver extension and the end plate so since these are used parts you can see they're kind of beat-up I've staked this one at least once and it was a poor job actually and some good wear on this commercial receiver extension which I really don't like but when you're building out of a bin of old parts you know that's kind of whatever so we're going to kind of get that kind on there just like that and then we're going to spin the vise around again alright so now we have our buffer retainer hole and that's going to need the buffer retaining spring the buffer retaining pin depress that and we're going to try to do this backwards here there we go just like that you see how the buffer tube keeps the pin captive alright so now we're down to torquing down the castle nut and to do that we need to get this spring safely into the hole just like that without kinking it or bending it or anything like that now we're going to tighten the castle nut by hand and stop right about there so the next step is to use an Armorer's wrench and this is the Magpul Armorer's wrench probably the best one out there right now that's readily available I'm sure there's some little mountain pop shops or building something that's better but slip that over with the teeth facing out this is intended to be used just like this so this part kind of supports itself on the castle nut itself then you've got a teeth to lock into the little cutouts this sides intended to be used with one of MAG poles proprietary tubes or it either that or it's the end plate that has a sling mount built into it but you don't need it when you're using just a standard buffer tube Castleman rather just kind of torque that down a little bit it's pretty close to lined up you use the wrench to kind of straighten the tube now because this thing is a commercial receiver extension the guys lis receiver extension black won't work with it and I prefer using that because you don't have a problem with the receiver extension twisting and doing weird things but unfortunately because this is a commercial extension the reaction block doesn't work all right so now we've got the receiver extension and the castle not all torque down everything's in place and we've done everything that we can do without a hammer now we need to involve a hammer and that's where the stair at number26 4e taper punch comes into play and this is what I'll use to stake the castle nut end plate the good deformation of metal a little bit more all right we're going to do it one more place unfortunately we're going to do it kind of in a goofy way because I can't turn it on the block so that's all done we'll touch that up with some cold blue here in a little bit that is a really rough crappy input kind of damage the castle out there but that's okay because this is kind of a beater rifle and people use all kinds of weird stuff for this like vise grips and painters tape and adjustable locking wrenches and all kinds of goofy stuff that ends up marring the finish now all you really need is one of these flattened punches from Brownells and a bit of tape so you take the bit of tape stick it on the punch just about like that stick your roll pin on there and fold it over so now your pin is on your punch and then we'll take the spring and detent slide it in the hole and then take your bolt catch and set it in place take another roll pin and area another open punch rather slide it in from the other side just like that and [Music] I've got a brass and nylon gunsmithing hammer that I like to use so we will locate that in the hole just like that and tap it in all right now that's in there I can pull the tape off finish that guy out there you go works just fine and we don't have a single scratch on that particular part of the receiver all right so the trigger guard is the last bit that we need to ham before you need your trigger guard roll pin a roll pin starter and then obviously your trigger guard so the trigger guard snaps into place here pressing that g10 ten snaps into place and then line up the holes grab your open starter in the roll pin drop in the hole and roll pins now started so we haven't had anything break or anything like that yet then just finish it off all right so now that's in place and we're good to go there so the guard is in place and if you really care you can test to make sure that it swings I depressing that detent and swinging it out of the way so that works you just like it's supposed to now the last step is to put it back on the vise insert the buffer spring in the buffer and put the sock on alright so now we're going to insert the buffer spring drop that the hole and kind of stays in place on that pin then take your buffer push it in so that's done there and last step is to grab your stock this is just a cheap green commercial stock I had in my bin of junk and you know set it on the back of the receiver extension pull the thing down slide it on in a lock in place and there you go so this previously unwanted pile of parts is now a complete lower and now we can build the upper for it next week with a bunch of other unwanted parts and maybe test the heck out of it [Music]

Channel: TFB TV

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Keywords: gun, firearm, tfb, shooting, How To, Build AR, AR-15, Lower, 5.56, lower receiver, Patrick R., TFB TV, Patrick TFB, TFB, howto, build, receiver, ar15, ar 15, shooting sport (sport), firearm (sports equipment), rifle, assembly, firearms, guns, tactical, 223, 556, magazine

Id: z7MGhlwkLk4

Length: 16min 50sec (1010 seconds)

Published: Fri Apr 21 2017