Want to build AR, missing anything?

May I suggest an 18" barrel.

The only tool I use in addition to those is a tap and die kit. On one of my builds, the grip screw broke off because of imperfect finishing on the lower screw holes. Now I clean the threads with a tap and buy a higher grade screw.

I would skip the quad rail unless you specifically want one. The ALG (same company as Geiselle) EMR V2/MLok rails are lighter and more comfortable to grip. MI is similar. You can still put rail sections where you want them.

Buffer tube. I like the Vltor A5 system, carbine convenience with rifle recoil and reliability.

As for tools you don't need a pivot pin install tool. Just use a razor blade or something similar (or a wooden dowel/drill bit/whatever) to hold the detent in until you install the pin. I'm also not sure what you mean by a bolt catch pin punch, but I've never needed one, just used a standard roll pin punch.

No appreciable difference, other than looks really.

Sight radius, especially since you've chosen a free float system, is the same, and the velocity differences are negligible.

However, since you're floating the barrel, a nice 18" barrel from a quality maker with a mid length gas system makes for a slick looking, accurate SPR.

So, merely an aesthetics suggestion.

theres really not much difference in velocity in an 18 inch barrel vs a 16, the 16 is more versatile.. heck id tell him to get a 12 inch if he could legally do so, but a 16 would be fine.. i dont think sight radius matters so much, if he's using flip ups then they are probably just going to be his backups to some other optic

Don't forget the gas tube, that's not in your list. I've only seen upper parts kits include a port door and forward assist.

The Magpul UBR stock includes its own, unique, buffer tube also.

You'll need an upper receiver block to hold the upper while torquing the barrel nut and flash hider.

The headspace gauge is kinda optional. Barrels are headspaced when the extension is put. I bought a no-go just to be safe though.

Looks like a fun build.

The point of Mlok is that you don't need rail covers. You only put on a rail where you need one, so presumably the rail is covered by whatever accessory is mounted to it.

lpsharp88 said:

Good call, will add that



I'll look into those



So does heat not transfer from the barrel/gas tube to the MLOK rail?

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They are heat shielded, so id assume it would take a considerable amount to warm the rails.

Just a little recommendation if you can afford it. If you can afford it I would highly recommend getting the JP silent capture spring and adjustable gas block (or any other brand of adjustable gas block). The Silent capture spring replaces the buffer and bufferspring and takes away the grittiness and annoying sound from the spring against the buffer tube which makes for a much more enjoyable shooting experience. The adjustable gas block along with that also makes it shoot even smoother since it won't be overgassed like most ARs are.

Save some money on the pivot pin installation tool and get a Clevis pin from Home Depot for $1.65 (I did that yesterday after trying to install my first pivot pin for 45 minutes the day before - I had the pivot pin installed before I even took my coat and shoes off with the Clevis pin)

I also only used vise grips instead of roll pin punches, on the bolt release and trigger guard roll pins (put the grips on the punch and slowly tighten by turning the knob). This is described in the AR15com forums. I wanted to build my lower this weekend and not wait for tools and save 38 bucks (for the Brownells set).

never mind I didn't read close enough,

Thanks for the heads up on MLOK! Do rail covers, such as Magpul XTM, etc, work on those rails?

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Unless I'm misunderstanding you, MLOK rails don't NEED covers, that's kind of the point. There isn't a rail there unless you're using it for something. Otherwise you've got a nice, clean, rail-free tube, like this one from Midwest Industries: https://www.midwestindustriesinc.com/index.cfm?fuseaction=category.display&category_ID=1266

Like this:


On that tube the only rail sections that are permanent are two on the top: a short bit in front of the reciever, and another short bit at the front of the tube, for your back-up iron sight. It comes with several MLOK rail sections you can attach if you want to mount lights or other gadgets that come with picatinny rails. Of course, you can also buy MLOK-direct-mount gadgets, too. Everything from grips, to go-pro mounts, and even a bottle opener... https://www.midwestindustriesinc.com/index.cfm?fuseaction=category.display&category_ID=1302

Having said that, there are MLOK covers that you can snap into those long holes now if you want to have something in there for whatever reason. https://www.midwestindustriesinc.com/index.cfm?fuseaction=category.display&category_ID=2495


Also:

1) That's an 18" barrel with a 15" M.I. tube.

2) No, the gas tube doesn't touch the rail anywhere (you can just see it inside the square channel if you look at the picture closely) and any heat from the barrel and tube tends to dissipate very quickly due to the space inside and all the holes for ventilation.

So does heat not transfer from the barrel/gas tube to the MLOK rail?

Click to expand...

I found my other pic:



You can see from that just how much room there is inside the rail for heat to radiate away. Yes, some of it is going to warm up the rail, but every handguard is going to pick up SOME heat from firing. With these really open rails little is captured and most just dissipates into the breeze.

Thanks for clarifying. I was more worried about heat transfer, but was unaware that they are heat shielded.

Click to expand...

They AREN'T heat shielded. Kind of the opposite actually. Instead of shielding/trapping the heat from getting to the rail, opening it all up so it dissipates quickly and doesn't heat the rail up so much.

Compare that perforated tube with a standard M16/AR15 handguard, and you can see exactly why those needed heat shields!

Unless you are shooting competition with mag changes at that station, heat isn't an issue. Steady state range fire doesn't make a handguard blistering hot. It was the contingency of full auto in the M16 that added the heat shields.

Not many bolt guns have heat shields - if the same kind of shooting is planned, they are unnecessary. Which goes to the purpose of the build. A gun needs a set of planned uses to then tailor it's list of features. Suggesting an 18" or 12" barrel highlights that - we have no idea how the OP will use it or why one would be a better choice than another.

Without that there is no reason to recommend one part over another other than good quality commodity milspec items.

As for the tools, the Arfcom sticky on assembly points out how to use common hand tools for it. Specialty armorer's tools are not necessary for a one time build, and the cost of acquisition goes directly against the budget taking away funds for an upgraded part - like, which red dot optic you could buy with the extra $100. Not to forget shipping, which eats up the budget with a $10 charge for every separate order. Be careful there as it will add up quickly.

With an idea of what kind of shooting the OP plans, some input could be offered. It very much does go to how far the targets are at, and are they paper or live? That affects the ballistics and bullet trajectory, the kind of bullet, what barrel it takes to reach that far, what optic will be used, what kind of handguard and muzzle device. Everything after that is mostly dress up, with the trigger pull set for either range or tactical use. The grip is mostly how much length of pull for the trigger finger and at what grip angle. The buttstock is largely Meh - all it needs to do is adjust for length of pull, where it will likely stay most of the time. Money spent on them past that is for nonfunctional purposes - dress up - hence be open to who offers the better functional choice, not what Brand is currently popular. Fit the parts to the purpose and the gun will be more effective at helping you shoot how you intend. Choose fashion and it's just a snapshot in time, dated for when the majority of parts were commonly sold. IE quad rail - an institutional compromise to mount a lot of different kinds of accessories, adopted a long time ago, and definitely not the current state of the art. DOD doesn't keep up and can't afford to, whereas we can take advantage of an incrementally improved part like a slick tube with your choice of mounting holes. Keep in mind almost nobody ever used 4 feet of rail, same with all those holes, most are left empty. Nobody likes dead weight, and experienced shooters avoid it unless they have a specific reason.

So, what kind of targets are being considered, and at what ranges? No way to tell if the parts listed are appropriate without that.

Looking at easy to install free float rails, I would say an ALG Defense EMR in M-lok is a great choice. I installed one on my AR in no time flat and with little difficulty. It's incredibly light and doesn't seem to get to hot even with multiple strings of fire (might just be the tiny NJ mags).

Also, instead of channel lock pliers, Sear's Robo-Grip pliers make installing pins for the bolt catch and trigger guard a breeze, just wrap the jaws in masking tape.

Lastly, a snap cap or sized spent casing comes in handy for aligning the gas block. This is something I ran into putting together my first upper. Even though the tube and block appeared to be straight on, the gas block hole was ever so slightly constricted and this caused the gun to short stroke. So what I learned from my internet searches was to plug the barrel with something and blow into the muzzle end (I know, kinda crazy sounding) while trying to align the gas block. The point where the air runs through the tube freely and with least resistance is where you should tighten the block down.