First AR-15, 4 - 4.5 lb

[Meta-Prometheus]

OP - Take a look at this video series: https://www.youtube.com/watch?v=HZrD...V-8xr8m6LaW18Z

You might be able to use a few ideas from this individual's build to help you decide what you want. It even looks like you have selected most of the same parts already. It also seems to have an appropriate build name, Project Lightsaber. I hope it can give you some ideas!

I hope that you will be able to achieve what you want out of this build, even if it is at a high cost. Good Luck.

[KUSA]

Are you guys capable of reading and comprehending?

If you don't have something constructive to say, PLEASE leave my thread and troll somewhere else.

Here my questions:

- Do you guys see any compatibility issues

You come here wanting advice. Many people tell you that it isn't a good idea to have the Handguard that long compared to the barrel.

My apologies if I upset you. However, you seemed a bit rude in the above post.

[jerrysimons]

I posted a photo of this setup and wrote twice that this setup was build and tested without any issues.

https://www.m4carbine.net/showthread...15#post2266515



Are you guys capable of reading and comprehending?

If you don't have something constructive to say, PLEASE leave my thread and troll somewhere else.

What exact barrel with length and KMR rail length is that? Link? Judging by that photo it might be ok with THAT set-up, since the blast baffle, by a fair amount, is still ahead of the end of the side of the rail where the gas is getting redirected. I can't say it is advisable but THAT set-up would maybe be ok. Keep in mind barrel lengths can differ slightly even from the same manufacture and same barrel type. Definitely mock it up first! Use shims from Precision Armament to get some extra length past the barrel threads but don't over do it. Also, last I heard from Joel at V7WS, they had a service for pinning and welding their TI muzzle devices to barrels, but contact them to confirm they are still doing it.

The rail is already here and a must. I might get a 16" pencil barrel and cut it flush with the rail and no muzzle, or have a 16” cut and threaded to clear the muzzle 100%. Not sure yet. A couple washer would probably also clear a 14.5”.

What I’m not sure about so far is the buffer and spring. What would be a good match for the 5.6 oz BCG?

It doesn't make any sense whatsoever to spend money on a TI bolt carrier and use any sort of buffer heavier than a carbine buffer. The reciprocating mass of the whole assembly must be taken into account. So you have three options: carbine buffer, gutted carbine buffer, or Taccom ultra light deralin buffer. Go with a SpringCo white spring over a standard mil-spec carbine spring. The material used is lighter. The white spring is also .1oz lighter than SpringCo a blue spring. Bolt bounce was brought up in a video in this thread and yes it is an issue for full-auto guns and in a semi-auto, duty gun I would seek to eliminate it for durabilitie's sake, but if this gun is a semi-auto range-toy, as you say, don't worry about it. The bolt will settle before you can pull the trigger again and you are not worried about accelerated bolt wear or replacement.

You definitely need gas regulation messing with a light weight reciprocating assembly. Go with a SLR rifleworks titanium Sentry 6 (SIX/.625") gas-block and don't look back (but you will have to cerakote it to get it black, I can give you tips on how to prep it beforehand or just call SLR). OR you could use a black BAD .625" titanium gas-block (the lightest I know of) and use an adjustable carrier-key set up. This method does work so far, but I am still in the process of hashing it out. Keep an eye on my sub 4lb SBR for updates since I am running both.

Also you said you are using the BAD saber tube set-up? Which one did you get, end-plate or non-end-plate version? You are stuck with their end-plate if you got the end-plate version since the tube does not have a groove for a regular end-plate notch. If you got the non-end-plate version, it will be a little lighter by deleting that part but you will have to make sure your take-down detent spring hole on the back is tapped and has the retaining screw with a shortened take-down detent spring in the hole. I think the BAD receivers are already tapped for a retaining screw but you will have to cut the spring and if you go with the lighter and superior looking (IMO) 2A Arms Balios-lite lower, you will have to tap the hole for threads too.

Aluminum is lighter than titanium, pay attention to what V7WS lower parts you are ordering, like take-down pins. Their aluminum stuff is blackened and lighter, so obvious choice for you. The V7WS bolt catch is S7 tool steel, do not get a titanium bolt catch from one of these other companies like redmist pointed out, not a good application for the material.

[IronMaiden]

OP - Take a look at this video series: https://www.youtube.com/watch?v=HZrD...V-8xr8m6LaW18Z

You might be able to use a few ideas from this individual's build to help you decide what you want. It even looks like you have selected most of the same parts already. It also seems to have an appropriate build name, Project Lightsaber. I hope it can give you some ideas!

I hope that you will be able to achieve what you want out of this build, even if it is at a high cost. Good Luck.

Thank you for the link, went right into my Favorites folder. That guy has indeed some of the same parts. Good link.

[IronMaiden]

What exact barrel with length and KMR rail length is that? Link? Judging by that photo it might be ok with THAT set-up, since the blast baffle, by a fair amount, is still ahead of the end of the side of the rail where the gas is getting redirected. I can't say it is advisable but THAT set-up would maybe be ok. Keep in mind barrel lengths can differ slightly even from the same manufacture and same barrel type. Definitely mock it up first! Use shims from Precision Armament to get some extra length past the barrel threads but don't over do it. Also, last I heard from Joel at V7WS, they had a service for pinning and welding their TI muzzle devices to barrels, but contact them to confirm they are still doing it.

It doesn't make any sense whatsoever to spend money on a TI bolt carrier and use any sort of buffer heavier than a carbine buffer. The reciprocating mass of the whole assembly must be taken into account. So you have three options: carbine buffer, gutted carbine buffer, or Taccom ultra light deralin buffer. Go with a SpringCo white spring over a standard mil-spec carbine spring. The material used is lighter. The white spring is also .1oz lighter than SpringCo a blue spring. Bolt bounce was brought up in a video in this thread and yes it is an issue for full-auto guns and in a semi-auto, duty gun I would seek to eliminate it for durabilitie's sake, but if this gun is a semi-auto range-toy, as you say, don't worry about it. The bolt will settle before you can pull the trigger again and you are not worried about accelerated bolt wear or replacement.

You definitely need gas regulation messing with a light weight reciprocating assembly. Go with a SLR rifleworks titanium Sentry 6 (SIX/.625") gas-block and don't look back (but you will have to cerakote it to get it black, I can give you tips on how to prep it beforehand or just call SLR). OR you could use a black BAD .625" titanium gas-block (the lightest I know of) and use an adjustable carrier-key set up. This method does work so far, but I am still in the process of hashing it out. Keep an eye on my sub 4lb SBR for updates since I am running both.

Also you said you are using the BAD saber tube set-up? Which one did you get, end-plate or non-end-plate version? You are stuck with their end-plate if you got the end-plate version since the tube does not have a groove for a regular end-plate notch. If you got the non-end-plate version, it will be a little lighter by deleting that part but you will have to make sure your take-down detent spring hole on the back is tapped and has the retaining screw with a shortened take-down detent spring in the hole. I think the BAD receivers are already tapped for a retaining screw but you will have to cut the spring and if you go with the lighter and superior looking (IMO) 2A Arms Balios-lite lower, you will have to tap the hole for threads too.

Aluminum is lighter than titanium, pay attention to what V7WS lower parts you are ordering, like take-down pins. Their aluminum stuff is blackened and lighter, so obvious choice for you. The V7WS bolt catch is S7 tool steel, do not get a titanium bolt catch from one of these other companies like redmist pointed out, not a good application for the material.

Now we are talking. Finally some really good info that I can work with. Thanks for jumping in Jerry.

The KMR rail I have here is the 15” version. The planned barrel is the Faxon 4150 QPQ with 14.5”. I changed that, my original plan was the Ultra Light VooDoo 14.5”

I remember that the rail in the photo is also a KMR 15” and they paired it with the VooDoo Ultra Light 14.5 barrel.

I’ll see how it stacks up. If it needs just a bit more clearance I’ll get those shims from Precision Armament. I’ll also contact V7 regarding the welding. I do have a local Ti guy but you never know.. firearms are not his daily job, at all. That’s great info right there and what I was hoping for!

The SpringCo white spring and Taccom ultra light deralin buffer just went right on the list.

For now I’ll stick with the adjustable gas block from SLR Rifleworks. What adjustable carrier-key set are you testing?

The Saber tube I ordered is the none end plate, mid length version. I’ll have to come back to you regarding cutting the spring.

I have the lightweight BAD set on order since a week, should be here in 3.

I almost didn't see the difference on the V7 site, their online shops takes a bit to get use to. Before I’ll order the V7 stuff I’ll post it here just to make sure I’m not missing parts.

Thanks again for your post, much appreciated.

[Livefreeordie92]

I’m in the process of buying the parts for my first AR-15 build and could need some pointers on my way.

The rifle will have no distinct purpose. When it runs decently I’ll take it to the rang and if it runs reliable I’ll keep it around for HD, but basically this build is all about fun and learning.

Here the list of requirements:

- needs to be lightweight, around 4 – 4.5 lb without sights and mag
- parts need to be of high quality
- entire rifle needs to be black
- 14.5” barrel plus 1.5+” muzzle device
- 15" rail for a "flush" look with the barrel
- no poly or carbon receiver / hand guard / stock


Here is my parts list so far, everything that is already ordered is green:

Receiver Set: Battle Arms BAD556-LW
Receiver Pins: Battle Arms BAD-EPS-Ti-B
Rail: BCM KMR BCM-KMR-15-556-BLK
Stock: Battle Arms SABERTUBE-M-B-COMBO
Trigger: Elftmann 3-gun Match
Grip: B5 Systems P-Grip
Ejection Port Door: Strike Industries
Sight: Aimpoint Micro T-2
Sight Mount: Scalarworks LDM/Micro

Barrel: 14.5" Mid Length Faxon 4150 QPQ
Gas Block: SLR Rifeworks titanium Sentry 7
BCG: SCT Titanium Bolt Carrier Group
Buffer: Rainier Arms Carbine
Charging Handle: V7 Weapon Systems Aluminum lightweight AR-15
Magazine Plate: MagPod

Muzzle Brake: V7 Weapon Systems FURION Satin Ti Black
Gas Tube: V7 Weapon Systems Titanium
Barrel Nut: V7 Weapon Systems Titanium
Buffer Tube: V7 Weapon Systems
Buffer Spring: V7 Weapon Systems
Castle Nut: V7 Weapon Systems Titanium
Buffer Retainer Pin: V7 Weapon Systems Titanium
Mag Release: V7 Weapon Systems Titanium
Bolt Catch: V7 Weapon Systems Titanium
Safety: V7 Weapon Systems Titanium
Grip Screw: V7 Weapon Systems Titanium


Here my questions:

- Do you guys see any compatibility issues so far?
- Any parts that will be a better or lighter fit?
- Which of the 3 BCG would be best?
- Am I missing something?

What you're searching for does not exist. You may get low 5 lbs but is that worth the cost of all those specialized, non standard parts? Just grab an ELW KMR upper and build up a lightweight lower.
And as for the longer rail, you're getting our constructive opinions. If you just want to hear how awesome this sounds, this isn't exactly the place that's going to happen.

[Livefreeordie92]

Here's the thing man, as a first AR there's a good chance this thing will cause a lot more headaches than something proven to be reliable, I.E. A Colt or BCM. That's what we're getting at. Start to go unorthodox with stuff, you may figure out the hard way why those parts aren't standard.

[IronMaiden]

Here's the thing man, as a first AR there's a good chance this thing will cause a lot more headaches than something proven to be reliable, I.E. A Colt or BCM. That's what we're getting at. Start to go unorthodox with stuff, you may figure out the hard way why those parts aren't standard.

What you're searching for does not exist. You may get low 5 lbs but is that worth the cost of all those specialized, non standard parts? Just grab an ELW KMR upper and build up a lightweight lower.
And as for the longer rail, you're getting our constructive opinions. If you just want to hear how awesome this sounds, this isn't exactly the place that's going to happen.

"Doesn't exist"? "May get 5 lb"? How about reading the entire thread? Parts so far are at 62.84 oz = 3.93 lb. Another guy just posted today a very comparable build, also at 4 lb. What was the last time you build a 4 lb AR-15? Never? I see. What I spend my money on is my business. If stuff doesn’t work out - I also said that before – I’ll try other parts. Even if I end up with parts worth $20k. I do not care. This is not about money. How many times do I have to repeat that?

I asked specific questions and not what kind of build I should put together. By totally ignoring my build-requirements you make yourself what? Ignorant. Move on. Don't bother to reply. Ignored.

I think I move this build to PM communication with those who are actually on topic. Not worth dealing with this.

[MtnMan6114]

Following.
Kudos for the attempt of the build if nothing else, (from someone with health issues that a light weight AR is the first priority). With all the poly and carbon fiber lowers and uppers that are being manufactured it will be awesome to see the finished result come in at the specified weight using metal. And if there are issues-fix them! Thomas Edison didn't build the electric light bulb on his first attempt.
Pictures would be nice too...

[Fluffy Bunny]

I guess I'll add one more post to this thread.

Do you have any 3 gun action nearby? If I was going to throw a rifle together with the lightest action (bolt buffer etc) I would definitely try to speak with some sportsmen about their experience. Online forums aren't everything. At the very least someone might share a reloading recipe you might like.