Ultralight Rifle Build Goal
My goal for this rifle build was to build an ultralight semi-auto long-range rifle that was capable of multiple precision shots out to 1000 yards and weighed less than 7 lbs. Multiple precision shots at 1000 yards isn’t a difficult goal at all in today’s world and there are lots of off-the-shelf $1500 rifles that can do it. However, most of them weigh a lot more than 7lbs or have sacrificed in the barrel department with short pencil profile barrels that aren’t capable of long-range precision. I wanted repeatable precision and excellent ballistics.
Table of contents
- Ultralight Rifle Build Goal
- A Magnesium Rifle
- Thixomolding and Die Cast Magnesium
- Extruded and Forged Magnesium
- ROAM Rifle’s Magnesium
- The ROAM Ultralight Handguard
- ROAM R10 Ultralight Upper Receiver
- ROAM R10 Ultralight Lower Receiver
- 6.5 Creedmoor Barrel by ODIN Works
- JP Rifles Bolt
- Triggertech Adjustable Trigger
- V Seven Castle Nut and Endplate
- V Seven Ultralight Takedown Pins
- Forward Assist
- KynSHOT RB5004 “Shorty” Recoil Buffer
- Superlative Arms .750 Titanium Adjustable Clamp-on Gas Block
- Future Forged Vector-5 Precision Rifle Grip
- Mission First Tactical BATTLELINK Minimalist Stock
- Presma AR-10 Charging Handle
- Radian Weapons Talon Safety Selector
- Magazine Release System
- AB Suppressor Raptor
- Other Notable Parts or Accessories
- Total Weight of the Ultralight Semi-Auto Long-Range Rifle
Why 6.5 Creedmoor in an Ultralight Long-Range Rifle?
In this build, I chose to use 6.5 Creedmoor because I felt like it was a good combination of downrange energy, decent velocity, and excellent bullet selection. Heavier bullets than 6mm Creedmoor and better long-range ballistics than a .308.
It was determined that for long range I needed a 22-inch barrel to push bullets a little faster – something that was going to be difficult to keep weight down as most ultralight builds use 16 or 18 inch barrels, not a 22 incher.
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I started choosing components carefully and now, after using and shooting the gun since last fall, I’d choose most of them again.
A Magnesium Rifle
While researching semi-auto ultralight rifles I stumbled across ROAM Rifles, a company specializing in ultralight AR10 platform rifles made from magnesium.
I was under the mistaken impression that magnesium couldn’t be strong enough to work in AR-style rifles and almost dismissed the idea of trying one out. Curiosity got the better of me and I actually called the company and found out that they were a company neck-deep in aerospace magnesium manufacturing and coating. ROAM Rifle Company was a startup side business. They had/have technology, metallurgy, and coatings never before seen in the firearms industry.
They assured me that the magnesium they were using was stronger than 6066 aluminum and about 33% lighter! This is not the same magnesium type or process of a certain company that was making magnesium lowers 5-7 years ago and that went out of business. That company was using die-cast magnesium.
Thixomolding and Die Cast Magnesium
There are two types of Magnesium parts. The majority of magnesium parts are made from thixomolding and die casting. Thixomolded and die-cast magnesium parts are what the auto industry uses because it’s a cheap way to make magnesium parts that are lightweight and sufficiently strong as needed for that application. However, they are somewhat brittle.
Extruded and Forged Magnesium
The aerospace industry also uses magnesium parts that are made from high-strength magnesium alloys that are extruded and forged. These are much stronger and are used in almost all helicopters as well as in jets like the F-22 Raptor. These extruded or forged alloys are much more expensive to manufacture and are substantially stronger than traditional die-cast magnesium.
ROAM Rifle’s Magnesium
The magnesium used for the uppers, lowers, handguards, and other magnesium parts used by ROAM Rifles are high-strength magnesium alloys that are forged or extruded. Their primary business is in the aerospace community and they know their stuff when it comes to magnesium alloys and coatings.
I ordered a stripped upper, stripped lower, and handguard. I paid for them personally as this was a personal project.
When the upper, lower, and handguard arrived I couldn’t believe how much they had in common with feathers. The weight was ridiculously light. I was impressed with everything about them but wasn’t convinced the whole thing wasn’t going to shatter if dropped after being assembled. It was hard to believe that something that light could also be strong.
The ROAM Ultralight Handguard
The handguard, which is 17 inches long and came in FDE Cerakote from ROAM, has only a small section of Picatinny rail in front of the upper receiver and a couple of inches at the end, which was fine for a long-range lightweight build. A couple more grams could probably have been lost by doing a traditional 15-inch length handguard but I liked the extra two inches personally for protecting the +2 gas system and mounting the bipod out further.
The handguard has M-LOK slots up and down the entire length of the bottom and sides of the handguard. It’s fitted to the upper receiver very tightly and has been sufficiently sturdy.
One thing to note about the handguard is that ROAM has since changed the design slightly to an improved version and this handguard pictured is no longer available.
Handguard Weight: 8.9 Ounces
ROAM R10 Ultralight Upper Receiver
There are two options for upper receivers at ROAM. The first option is without a forward assist and the second option includes one. The slick-sided one is a few dollars less and is lighter in weight. I chose the one with forward assist as I wanted to be able to close the bolt quietly in hunting situations if the need arose.
ROAM Upper Receiver Weight: 8.4 oz
Price: $ 279.95
ROAM R10 Ultralight Lower Receiver
Don’t really know what to say about this except it’s really lightweight. It has nice lines that match well with the upper receiver.
R10 Lower Weight: 7.2 oz
6.5 Creedmoor Barrel by ODIN Works
I called and told ODIN Works what I was trying to do as I’ve had excellent luck with their barrels in the past and they did a custom contour for me that knocked some weight off of their stainless match 22 inch 6.5 Creedmoor barrel. We certainly could have taken more metal off but I wanted a shooter. This barrel features a rifle length +2 inch gas port. In other words, the gas port is 2 inches longer than a standard rifle-length gas port, which is great for higher pressures and use with a suppressor.
Specifications of the ODIN Works Barrel
- Profile: Tactical Match
- Length: 22″
- Gas Placement: XL Rifle
- Weight: 3.38 lbs (2 lbs 12.2 oz after contouring)
- 1:8 twist button rifle
- Made from 416R Stainless Steel
- M4 Feed ramps
- 5/8-24 Threading
- 1″ MOA guaranteed
- Includes XL Rifle gas tube
ODIN Works Barrel after contouring – Weight: 2lbs 12.2 oz
Price: $440 (includes gas block and +2 gas tube)
ODIN Works 6.5 Creedmoor | 22″ Tactical Match +2″ XL Rifle | Barrel
I also painted the barrel using Brownells Aluma Hyde II spray paint and have been very happy with the results simply air/sun drying it.
JP Rifles Bolt
JP Rifles makes great stuff and their low-mass bolt carrier is no exception. At some point, I may switch for a carrier with forward assist notches. I used their smaller firing pin hole to handle higher pressures (JP refers to this as their EnhancedBolt). I already had a low mass bolt carrier from a previous 308 build and simply added the EnhancedBolt head.
Weight: 14.4 oz
Price: $485 (complete bolt carrier group)
JP Large Frame LMOS Carrier Group with JP EnhancedBolt
Triggertech Adjustable Trigger
I had a Triggertech Diamond Adjustable trigger on the shelf already and for a precision build it made sense to use. I’ve become a much bigger fan of flat triggers as it allows you to put your finger at the bottom and use leverage to decrease the trigger pull. The trigger is adjustable from 1.5-4 pounds. I installed the AR-15 version of the trigger and Triggertech makes the same trigger in an AR10 version, which I would’ve used if I’d had one. I have had no issues using the AR15 version. I’ll link the AR10 version below. These triggers feature what Tiggertech refers to as Frictionless Release Technology, and in my opinion, they’re one of the best and most robust triggers for precision applications.
Weight: 2.2 oz
TriggerTech AR10 Diamond Trigger
V Seven Castle Nut and Endplate
Trying to cut every possible ounce, I chose to use an aluminum castle nut and endplate from V Seven. The castle nut weighed 6 grams and the endplate weighed 4 grams.
I installed these later after having previously installed the steel versions. The steel versions together weighed 30 grams. I’ve had zero issues with them and would use them again. I don’t use the QD in the endplate but it’s there if needed.
Castle Nut Weight: 6 grams
Endplate Weight: 4 grams
V Seven Ultra-Light Endplate Castle Nut Combo Pack
V Seven Ultralight Takedown Pins
I originally installed steel takedown pins and switched them out for these V Seven ultra-light aluminum takedown pins. Hundreds of rounds later they have worked great with no discernable wear. The steel takedown pins that I replaced them with weighed 21 grams.
Weight: 7 grams
V Seven Ultralight Takedown Pins
The original forward assist that came installed from ROAM was steel and weighed 22 grams. I found that Strike Industries makes a lightweight version out of aluminum with a steel pawl and it weighed just 11 grams.
Weight: 11 grams
Strike Industries Lightweight Forward Assist Assembly
KynSHOT RB5004 “Shorty” Recoil Buffer
The KynSHOT Shorty Recoil Buffer is advertised as reducing felt recoil 20-30%. While I have no way of measuring that number, I can tell you that this rifle shoots smooth and the recoil is extremely mild. It’s honestly not much more than an AR15 shooting 556. This buffer is specifically for AR-10s using a 7.0-inch collapsible buffer tube. The buffer is hydraulic but will work at temperatures down to -30F.
For comparison purposes most of the heavier AR10 buffers that you would use in a suppressed 6.5 Creedmoor weigh between 4.5-5.5 oz.
Weight: 3.7 oz
KynSHOT Precision .308 Shorty Carbine Recoil Damper – 2.5″
Superlative Arms .750 Titanium Adjustable Clamp-on Gas Block
If you’re going to suppress your AR style rifle, the Superlative Arms Adjustable “bleed off” gas block is the best there is. When adjusted correctly it allows gas to bleed off out the front of the gas block rather than pressurize your gun and send gas back into the system.
The benefits of an adjustable gas block, especially suppressed, are huge for reducing wear, over-gassing, felt recoil, reduced bolt speed, faster follow-up shots, increased reliability, and overall wear and tear.
All adjustable gas blocks will give those benefits but the Superlative Arms gas block does it a little differently. Imagine water in a hose. No adjustment in the gas block means that all of the water that fits in the hose goes through the hose. A standard gas block is simply a restriction in the hose to “hold back” some of the water. The Superlative Arms gas block creates a Y. The extra water/gas not needed is allowed to escape out the front. You can adjust how much or how little that happens with the detented screw. The gas block itself never seizes or carbons up and you don’t get erosion because of the design.
I wanted the clamp-on style so as not to add a pressure point in the barrel with set screws. Titanium was the preferred material because it was lighter than steel. Superlative Arms does make a steel version as well which is less money.
Weight: 1.07 oz
.750″ Titanium Adjustable Gas Block, Bleed Off – Clamp On – Dark DLC Finish
Future Forged Vector-5 Precision Rifle Grip
I had never heard of Future Forged prior to starting this rifle build. I actually called and talked to the owner and he was very knowledgeable and has some really crazy great tech that he can do with grips. Like, he can create a custom grip specific for your hand.
In this case, I wanted a lightweight precision (more vertical) grip with a thumbshelf on the right side of the grip. At the time, that was only available in a prototype. It’s now a full-production model called the Vector 5.
The Future Forged grips are made from carbon fiber reinforced polymer and are designed for ergonomics, comfort, and for ideal trigger finger placement.
I couldn’t be happier with how the Vector 5 has performed. It’s insanely lightweight and it’s very comfortable and strong. I’d buy it again in a heartbeat.
Future Forged also has a hollow titanium screw that weighs almost nothing for attaching the grip to the rifle.
The Vector 5 grip weighs almost 1 oz less than a standard plastic cheapo AR-15 grip and almost 2 oz less than the ERGO grip it replaced.
There are multiple colors, styles, shapes, and custom offerings from Future Forged. Future Forged offers a lifetime guarantee.
Weight of Vector 5: 2 oz
Future Forged Vektor-5 Precision Rifle Grip
Mission First Tactical BATTLELINK Minimalist Stock
One of the most overlooked AR style stocks in the world is the Mission First Tactical BATTLELINK Minimalist Stock. It’s one of the lightest, weighing only 5.8 ounces. It has actual rubber on the buttstock, QD mount, is fully adjustable, and is one of the few stocks that doesn’t pull my beard hairs. It’s also priced very competitively with everything else out there.
Weight: 5.8 oz
Mission First Tactical BATTLELINK Minimalist Stock
Presma AR-10 Charging Handle
I really cheaped out on the charging handle. It’s fully ambi. Lightweight and cheap.
I bought it at AR-15 Discounts and so far have no complaints. I didn’t like the other options available for one reason or another.
Radian Weapons Talon Safety Selector
The Radian Talon 45/90 safety selector was chosen because of three reasons, I love 45 degree safety’s, wanted it to be ambi, and it’s very lightweight. I weighed a Battle Arms Development Safety and it weighed 21 grams compared to the Radian at 14 grams. I also ground down the right side to better fit with my grip.
Weight: 14 grams
Radian Weapons Talon Safety Selector
Magazine Release System
At some point several years ago I bought an aluminum magazine release system from China through AliExpress. I can’t find it now so you won’t get a link but it cost something like $3 shipped and it weighs 5 grams. It’s held up great with no issues. The steel version which I replaced weighed 14 grams.
AB Suppressor Raptor
Having played with and shot many of the suppressors available in the industry, I chose a lightweight AB Suppressor Raptor. When you look at the pictures it’s easy to assume that it’s huge. What you don’t see is that it actually goes back over the barrel and creates more volume and reduces back pressure by having a huge initial first blast chamber.
It’s also made out of titanium and is very light. The part that goes over the barrel is called the Reflex and you have the option of taking it off if you want to lighten things even further. I felt like the reduced backpressure and extra volume were worth the couple of ounces it cost me. With the reflex installed, the tone is deeper or lower.
I’ve been very happy with the Raptor 6 and have shot multiple coyotes on one stand with it. The tone is great, I notice no gas in my face and because some of the weight is over the barrel the gun balances better.
Pictured is the Raptor 6 with a 6.5 Endcap and the 3 inch Reflex. Together they weigh just 11.6 ounces.
Weight: Just Suppressor 7.1 oz. Reflex 4.4 –Together 11.6
Other Notable Parts or Accessories
Seekins Precision MXM Scope Mount 34MM 1.45″ 20 MOA
Lancer Systems L7AWM® 10 MAGAZINE – This magazine needs to be tuned by cutting a coil. Directions on Lancers site.
Really Right Stuff TFCT MK2 Tripod 33 w/ Anvil-30 ARC Head
I shot both Hornady factory ammunition and handloads. The factory ammunition all shot minute of angle or better but all I have in factory ammo are 140 grain or heavier. I wanted to shoot the 123 grain and push them faster.
I ended up settling on a handloaded 123 grain Hornady ELDM load with a velocity of 2934.
Overall, I’m very satisfied with the accuracy of the gun and the ammo. The 123 grain load outperforms the 140 grain load beyond 1000 yards in drop and matches it in wind to 1000 due to the higher velocity.
Total Weight of the Ultralight Semi-Auto Long-Range Rifle
When I first put the rifle together, all of the lightweight parts hadn’t shown up yet and it weighed in at 6lbs 15.9 oz. That was no magazine, no suppressor, and no optic or optic mount.
I changed out the castle nut and endplate, the entire magazine release system, the forward assist, takedown pins, and the grip, and ended up with a total weight of 6.75 lbs or 6lbs 12 ounces. I lost 3.9 ounces by making those changes.
6.75 pounds rivals the lightest weight AR10s on the planet that are small frame, carbon fiber, pencil-thin 16 inch barrels, with short handguards, non-adjustable gas blocks, milspec triggers, etc.
I also want to point out that had my goal been to get down towards 4.5 lbs I think I could have done it pretty easily by using a lighter profile barrel, lighter stock, lighter buffer, non-adjustable gas block, shorter handguard, mil spec trigger, no forward assist on the upper, no ambi safety, smaller grip, etc. I wanted an ultralight Semi-Auto Long Range capable rifle and I built one.
The rifle as built is fully capable of hitting clay pigeons out to 1000 yards.
Let me know in the comments if you’d ever build something like this and tell us what components or parts you’d use.
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Very good and interesting achievement True, my hat to you. A bit too much on the expansive side for most sport shooters, but for a long range dedicated one it could be an option. Myself I have not ventured in the ultra light department because my caliber of choice is rather heavier than a 6.5 but for those who are satisfied with it, yes, you’ve accomplished something special. Thank you
Jeesh. All these comments crying about the price. If you want a Ferrari 296, you shouldn’t complain when it costs more than a Honda Civic.
I for one and astonished that you were able to build such an amazingly capable rifle at this weight. I understand your goal and appreciate your thoughtful execution. You can kill clay pigeons out to 1000 yards, deer and antelope out to 600 yards, and elk out 300 yards (with the right load). All of this in a handy package that won’t kill your forearms and traps as you burn the boot leather in pursuit.
I would absolutely love to see an ultralight build in an 18″ 6.5 CM as a GPR (general purpose rifle). This would be great for everything from home/ranch defense to deer hunting.
My personal two rifle battery is an ultralight 22″ 6.5 CM bolt gun and an ultralight 24″ 33 Nos bolt gun. I use my 6.5 GR gas gun for home/ranch defense. The 6.5 CM and 33 Nos are near external ballistic twins. Both bolt guns are the same model of rifle and have the same scope so the handling and DOPE are almost identical.
Your post has inspired me to ditch the 6.5 GR and build an ultralight 6.5 CM gas gun. One less caliber to stock up on and the 6.5 CM is so much more capable. POF makes a decent looking 6.5 CM gas gun but the poor reports on reliability have scared me away. I really had no idea that ROAM made such good kit. This forged magnesium stuff is impressive!
Nice build. This certainly shows how going beyond a “normal” build really cranks up the price. If you want to improve accuracy by 25% or shave about 20% of the weight it can easily increase the cost by 50-100%.
The target pics…the 2 shots in the black circle are the same in both pics. They are exactly the same 2 holes in the same target. So is that a 2 shot slow group or 3 like you said?? Cause if it’s 3…then the 4 holes to the left you call rapid fire group would make 7 not 6…and it would only be 4 shot group fired rapidly on the same slow fire target…jus sayin.
Very nice rifle, BUT… for the weight differences aside, I’d like to put my 20 inch custom built Bushmaster up against same with my stainless steel ribbed heavy barrel and titanium suppressor!
I doubt the accuracy would be that much different at distance, yet unless I am at a 1000 yard range which are getting very rare, I have not much call for that in taking out targets in an urban environment for which this rifle is specifically designed!
I actually now have three different AR’s designed and built for three different uses long range, medium range, and short range vehicle use, who are you gonna call? 👏🏽 👍🏼☺️
Based on my math the basic build is $2,814.71 plus the suppressor raises it to $3,594.71. If you add in the other notable parts and accessories it balloons even further to a total of $7,977.70 or just shy of $8,000.00. The mag is $50, the bipod is $389.99, the Scope using the cheapest one is $2,199.00, which could go to over $4K with an illuminated reticle, the tripod is $1,465.00, and the scope mount is $279.00. All prices found with a simple search on the web. Come to your own conclusions whether it is worth the weight loss.
I came up with $3600, plus the cost of the scope, mount, bipod, and tripod used in testing. $5K minimum. Quite a shooter. I was comparing the 6mm and 6.5mm Creedmoor, and still haven’t decided which way to go. I appreciate the effort with the small parts saving grams here and there. It all adds up. Nicely done.
Great build !!!!! You will inspire a bunch of these rifle builds. Can’t argue with anything you did. Can you tell me the total cost? Don’t have my calculator.
I question your logic behind insisting on a forward assist and using a bolt carrier without the forward assist serrations. I’ve always been suspicious of the J-hook style stocks thinking they are more likely to grab onto underbrush than even the mag-well or pistol grip. I imagine you also considered a carbon fiber wrapped barrel and am curious why you went with what I imagine is much heavier. And is that 1/2″ 3 shot group at 100 yards? Still, a very nice job, especially an AR-10 platform under 7 lbs.
My light-ish weight AR-15 build was put together with mostly accumulated parts and a few titanium bits bought for the fun of it. At an even 6 lb. it has several parts that could be replaced to save weight such as the Vortex Sparc red dot plus MBUS, Midwest Industries MI-21M handguard (which does fit nicely over the Superlative Arms piston kit) and the Magpul CTR stock. It has a Faxon pencil profile barrel attached to a Aero Precision slick sided upper. Before assembling all this around a much maligned MAG Tactical Systems lower I did some research. Every well documented breakage I could find involved something like butt-slamming to clear a jamb. Perhaps their fragile reputation stems around a curiosity of just how strong can something this light be? Hold my beer and watch this. And as I am partial to Geissele triggers it has one of those. It’s been awhile since since it has been to the range but considering my skill with a rifle the little frankengun does very well.