Thank you for the info. I need to do some more research.

build threads are always fun. It is living vicariously through your wallet.

If I can spend $7k on a wedding ring, can't I spend a little less on a nice rifle? I told her I was going to build a new rifle and her only response was, OK??

quote:

Originally posted by xantom:
16"light weight barrels must be in high demand. Wilson Combat and Ranier 16" fluted barrels are sold out almost everywhere. The proof barrel is not available either unless I got one with 1/8 twist.

Any other suggestions for a fairly light weight 16" barrel?

1/8 will stabilize everything that will feed from a magazine.

I wouldn't be spending all that extra coin on an uber lightweight build unless I was doing it specifically for run and gun (5k and 10k) matches, where you run while carrying all your guns and gear.


My 3 gun rifle weighs 11 pounds, and I like it that way. More stable for offhand shots and a heavier rifle has less sight disruption.


The easy place to save weight in an AR15 is in the barrel and in the stock.

Something like an ACE ARFX stock is fairly minimalist and light. And for the cost of all of those titanium parts, you could pay for a tax stamp and build a 12.5" SBR that will change the handling of your rifle a decent amount. Or you can just go with a PROOF, or a fluted, or a skinny contour 16". I like fat barrels because I like my zero to have minimal wander when my barrel is hot.


I just thought I would mention it before you got too far down the rabbit hole of a super light build.

Sounds good in theory. Is good in some application (being toted long distances on foot). But might not be the best for others. I wouldn't even consider an ultralight build for a precision rifle. For me, their best niche is for run and gun or rifles that are going to be carried for a long duration.

I see that you have a JP enterprises bolt carrier. I also see a spikes tactical heavy tungsten carbine buffer.


You are trying to shave weight in other places, then adding weight in the buffer. That doesn't make sense, especially if you are getting the JP enterprises low mass carrier.

You are literally paying extra for a light carrier, and then paying extra for a heavier buffer. The mass of those two are a coupled system.

Especially since you are getting an adjustable gas block.

Get a standard buffer, and you may actually find that you can take a weight or two (steel) out of it and replace it with a delrin spacer.

Your adjustable gas block will mitigate your need for a heavy buffer of any type.

digging the shark mouth

quote:

Originally posted by xantom:
2A Balios matched reciever set

Hoo boy those are pricey. How much lighter are they?


For that kind of scratch, you could buy a regular receiver set, and save money by going to a very high end but lighter weight optic like a Kahles K6i.



ETA: Looks like they are about 3 ounces lighter than a standard receiver set.

Great information, thank you.

The Balios set comes in at 12.4 ounces.

The buffer I picked comes in at 3 ounces. Can you point me in the right direction to a lighter buffer?

I am thinking of going to the less expensive rainier arms 16" barrel. It's about half the cost. Could probably put that into a better optic.

The tax stamp thing is a whole other issue. A friend and I are looking into setting up a trust. But haven't done much research into that yet other than getting some initial information. Probably not something I will sort out before I build this one.

quote:

Originally posted by xantom:

The buffer I picked comes in at 3 ounces. Can you point me in the right direction to a lighter buffer?

3 ounces is a standard carbine buffer. That would be a good choice. It will have 3 steel weights inside which you can remove if you choose, and replace them with a delrin spacer if you for some reason need to go lighter.

Adjustable gas gives you the option to go lighter than standard and have a very nice shooting gun indeed.

Some people assert that such guns are less reliable, but my 3 gun rifle has been operating that way for years with a single digit number of magazine induced malfunctions.



If you want to go fancier on the buffer. I have a JP SCS and I am a big fan.

https://www.jprifles.com/buy.php?item=JPSCS2-15K


On it's own I don't think it is a huge step change in how a rifle shoots.


Paired with adjustable gas, a low mass carrier and buffer. It makes for a very smooth shooting rifle.

Weight on rifles depends on where it is. And it depends on how the rifle is balanced.


A front heavy rifle, unbalanced, can be more difficult to control than a balanced yet overall heavier total weight rifle.


Similarly, mass in the area of the receiver doesn't change the perception of weight that much. Mass on the barrel, especially on the far end (like a heavy suppressor), can make a rifle feel MUCH heavier.


This is why I generally recommend to guys that are looking at all those pricey titanium parts, just look at their barrel contour/length, and their choice of stock.

A heavy optic can also significantly change the feel of a rifle. I mostly use Vortex Razors... and they are tanks. But I like them because of the durability, glass quality, and overall optical performance, as well as a great reticle.

Some guys find them too heavy and favor Leupold or Kahles, who do make lighter scopes.

Let's visit the AR's general configuration and purpose. You want a lightweight rifle for shooting steel targets at distances of 50-300 yards. This implies a primary purpose of training, competition, and/or plinking.

What are your primary reasons for a lightweight rifle?
- just because
- limited physical strength
- extremely strenuous shooting drills, which require a lighter rifle to complete the courses of fire
- extremely rapid shooting drills, which require a lighter rifle to score well in the courses of fire

Have you shot both lighter and heavier ARs in your standard courses of fire, to determine the pluses/minuses of each?

I have heavier ARs which I shoot in 2-rifle precision/tactical competitions. The ARs I've used most have 18" and 20" heavy-profile barrels, mid-power scopes, bipods, and suppressors. IIRC they weigh 13-14 pounds. The match courses of fire include steel targets of 150-600 yards, and paper targets of 5-75 yards. These matches are not shot from fixed-position benches -- they are physical, with lots of movement between and within stages. They are run by Competition Dynamics.

One match is the Team Safari, held at JP's Blue Steel Ranch in New Mexico. The heart of the match is 3 field courses -- a hike of 3+ miles and 8 shooting stages, spread out over 4-ish hours. Hiking time between stages isn't timed, but the stages are on the clock. Shots are taken from prone, off tripods, and from improvised support with rocks or trees. There are also 4 shorter assault stages -- faster paced, with movement on the clock, multiple targets, sometimes shooting with no rifle support.

Another match is the Team Challenge, currently held in Wyoming. The heart of the match is 3 field courses -- a walk/jog/run of 1.5 to 2 miles, 4 stages, across hilly terrain, with a time limit of 1 hour for all activity. Steel targets generally 250-600 yards out. Shots are taken from prone, off tripods, and from improvised support with rocks or trees. There are also 6-8 shorter assault stages -- much faster paced, with movement on the clock, multiple targets, and generally shot from unsupported standing or with tripod support (if time allows). Most people are out of breath and sweaty after every stage.

Even though my heavy AR15s result in greater physical challenges in these matches, I wouldn't trade them for lightweight builds. I doubt any of the other competitors would, either.

Some of the challenges of lighter rifles:
- Pencil profile barrels heat up and cool down faster than heavier profile barrels. Coupled with their thin profiles, lighter barrels exhibit reduced accuracy -- especially with higher volume shooting.
- Heavier rifles are actually easier to shoot accurately than lighter rifles. Assuming, of course, that the shooter has the strength to support the rifle.

****
Consider the barrel type with your shooting volume and accuracy demands.
- Stainless steel barrels will generally give you the best accuracy. Same for uncoated chromoly steel barrels. These barrels will have the shortest life, however. Maybe 5k rounds life for sub-moa match-grade accuracy at distance, although many shooters won't consider replacing them until 10k rounds.

- Chrome-lined chromoly steel barrels will generally give you the worst accuracy. You might get 15k to 20k round life, as long as you don't mind lackluster accuracy, especially at distance.

- Nitride/Melonite treated barrels in theory promise the accuracy of unlined steel barrels with the life of chrome-lined barrels. I have no experience here, but the theory is sound.

Thank you for the information.

I have a few rifles a DD AR, a Saiga SGL-21, and a Sig 716. I recently swapped out the furniture on my Saiga and was quite surprised by how much of a difference it made in handling and shooting. I also built a 10/22 and loved how light and nimble it is.



So just because, I really don't have a better answer other than that.

Any thoughts on this Steiner optic:
https://www.steiner-optics.com...lescopes/p4xi-1-4x24

I end up going with this barrel:
https://faxonfirearms.com/matc...el-teflon-extension/

Faxon does not dimple their barrels and I am not sure whether I should or not. Any thoughts on that?
https://faxonfirearms.com/blog...imple-their-barrels/

Any thoughts on that Steiner Optic would be appreciated too, thanks!

quote:

Originally posted by xantom:
I end up going with this barrel:
https://faxonfirearms.com/matc...el-teflon-extension/

Faxon does not dimple their barrels and I am not sure whether I should or not. Any thoughts on that?
https://faxonfirearms.com/blog...imple-their-barrels/

Any thoughts on that Steiner Optic would be appreciated too, thanks!

You can dimple a barrel fairly easily with a little jig. It helps ensure the gas block doesn't move around on you and that your gas port is aligned between the barrel and gas block. I would recommend it. Using a knurled set screw helps if you're not dimpling, but the dimple locks it in. There are tricks and tools for aligning the port for non-dimpled setups as well, the cheapest being the spaghetti trick. Only one dimple is needed, gas blocks all have different spacing so you can match the dimpling to yours and be out of luck if you ever need to change to something else in the future and end up fighting the front dimple with poor contact.

Steiner P4Xi 1-4 is probably the best 1-4 LPVO option on the market. Certainly one of the top contenders on anything south of $1,000 for LPVOs of any magnification range. Some Trijicon offerings are close or on-par, and you'd need to step up to something like the Razor GenII 1-6 to get a leap forward in glass and eyebox.

Ok yeah it makes total sense to me, but if you look at the second link they give their explanation of why they don't dimple it. Just curious if anyone had any strong opinions on why I wouldn't do it. I got the jig and am planning to do it. I assume it's more of CYA on their part. Thanks for the info on the optic. Sounds like it might be the one for me. I have everything ordered now just waiting for some of the things to ship.

quote:

Originally posted by xantom:
I have been thinking about building a lightweight AR for some time.
This is my first AR build.

I have built many AR's and do see you have some nice high quality parts.
I tend to do the same thing.
However, most all now are more precision and not all that light.
My favorite tack-shooter is a 20" WOA SDM 1-8 barrel, Geiselle Match Trigger on a Mega Arms upper + lower, Adams Arms piston (I know it isn't necessary ~ just wanted to try something) topped with NF F1.
Incredibly accurate, love it.
It is NOT light ~ 11lbs including the BT Atlas bi-pod.
So what is your target weight?
It is not so easy to get light and get accurate at the same time.
Looking forward to seeing how it comes out.
Good Luck.

Thanks! From the weights I compiled it will come in at 7.68 pounds with no ammo. The Steiner optic and Nightforce mount come in around 23ounces. I went with the Faxon Barrel and trimmed out most of the titanium pieces to get the cost down, but still came in just over 3k with taxes shipping and fees.

quote:

Originally posted by xantom:
Ok yeah it makes total sense to me, but if you look at the second link they give their explanation of why they don't dimple it. Just curious if anyone had any strong opinions on why I wouldn't do it. I got the jig and am planning to do it. I assume it's more of CYA on their part. Thanks for the info on the optic. Sounds like it might be the one for me. I have everything ordered now just waiting for some of the things to ship.

Dimpling Nitride is also a recipe for dull bits since Nitride is so hard. It's a fairly low-speed process if they don't do it as part of the barrel index stage. I don't know what sort of setup they're using to ensure the barrels are setup straight, but some do it after the extension is in place to properly time the index pin and gas port. If they time off the extension they might not be able to flip it and drill 180° from the gas port in the same process, so it's got to be done as an additional process. From their FAQ I would assume this is the case.

Corrosion? Idk, use some cold blue. I didn't treat mine, the gas block seal should stop any ingress of water or the like. I suppose it could be an issue, but I've run into and companies that pride themselves on hard-use, bombproof guns do a single dimple, red locktite, and just go with it. I have a bare SOLGW barrel, I can check to see if the dimple is done pre- or post-nitride.

Their reasoning for gas block spacing would make sense if doing a single dimple didn't give you the benefits with no drawback.

But they're correct - the discerning buyer looking for this likely has (as you do) a tool, or a source to get the dimple done.

Centurion uses a single set screw. I don't think anyone would argue their methods and products are anything short of top quality. They also index pin the gas block, and cross pin the gas block for their in-house builds. Belts, suspenders, and heck another belt just in case.

I recently did a build and like the following.
Odinworks o2 lite handguard (crazy light, somehow rigid)
Ballistic advantage barrel (Not super light but quite accurate and based on your range application I dont think ultralight is neccesary)
Larue flat bow trigger (one of the nicest triggers I've felt, cheap too)

My personal feeling is while ultra lightweight is nice you get to a point of diminishing returns, especially if you arent humping it over mountains or something. You'll spend alot to shave an oz here or there. Its your money but since you asked thats my input. A light HG and optic and not hanging a bunch of crap off the front gives you alot of weight savings.