Ultralight Ultralight Rifles

[Trackselk]

How does the rear bolt attach?

I'm still pretty new to AR's, but the 2 screw holes for the detent ball arm/ gas key is where I bolted it strait onto. I'll try to post a pic when I'm home in a week. Very solid, pulls and pushes strait in line with the bcg

 

[Trackselk]

I forgot to mention that the aluminum spacer also keeps the bcg from rotating and avoiding full battery. I filed it to within 1 thou of the width of the solo detent arm. Without it it wouldn't go into full battery

 

[SoFLBeachBum]

I forgot to mention that the aluminum spacer also keeps the bcg from rotating and avoiding full battery. I filed it to within 1 thou of the width of the solo detent arm. Without it it wouldn't go into full battery

That’s well thought out, and that the bolt carrier rides smoothly is a plus. I read the earlier posts about issues with larger cartridges in the Solo, I wonder if your design solves that problem. And plus, it is super light and minimalist.

 

[Trackselk]

That’s well thought out, and that the bolt carrier rides smoothly is a plus. I read the earlier posts about issues with larger cartridges in the Solo, I wonder if your design solves that problem. And plus, it is super light and minimalist.

Thanks, I should know pretty soon as I test sticky undersized brass and NAS3 cases in the new ackley chamber as hot reloads. If I made the grip part of it a lot longer I could strike it with my palm to extract, I mean, it would still be a lot faster than a muzzleloader.
Edit: make that *oversize brass (for the ackley chamber/crush fit)

 

[schmidty3]

Found a neat trick.

Faxon barrel with integral flashhider machined in (they also have a brake option). 1# 5oz.

Obviously not ideal for can use. But saves some weight on a muzzle device and gives you a "14.5" barrel" without doing a pin and weld.

May not be ideal for "hunting". But Im putting together a car-15ish build. ~5#. But a2 sight and midlength gas. Truck gun. And maybe a meat packing gun in grizzly country. And a lot of fun/vibes in 3 gun type activities.

 

[yfarm]

Just let the the outside of the barrel rust. It won't harm it. In addition, every time a bit of rust is knocked off and replaced with new oxidation, the barrel gets measurably lighter. Win-win!

I use ospho as a rust converter/ primer before painting on steel. Has anyone every used it on a barrel as a surface finish?

 

[StupidLightweight]

View attachment 1073910View attachment 1073909
May not be ideal for "hunting". But Im putting together a car-15ish build. ~5#. But a2 sight and midlength gas. Truck gun. And maybe a meat packing gun in grizzly country. And a lot of fun/vibes in 3 gun type activities.

Share more pics when it’s finished! I love retro ultralight builds. You may consider a slick side A1 upper to keep it even more simplistic if you’re a righty.

 

[Luke S]

Here is a close up of my rail ground down.

I really like the finished version. The center of gravity is lower. Very easy to carry.

 

[StupidLightweight]

Clever grinding. I like it!

 

[ProRoad]

I have been working on this build for a few months and finally have the Lower ready to show. I was holding out for my upper to be complete but realize that the Lower might qualify as ULUL, but as a gasser, the upper will only be UL. The weights are from my scale and may vary from claimed weights.

With the issues of ordering the TN Arms lower this year, I decided to try the ROAM R-15 Magnesium Lower.

The build with the following parts, weighs out at 1 pound, 10 ounces. (More than one pound+ lighter than my two other builds!)

• Lower Receiver: ROAM R-15 Magnesium. 5.5oz $300 (with this high cost item, I decided to go a bit more budget and compromise weight vs cost on some of the following parts.
• 
  
• Stock: Mission First Tactical Battlelink Minimalist Stock. 5.7oz $20 Pawn Shop.
• 
  
• Trigger: Geissele SSA-E X 2-Stage Trigger w/Lightning Bow. 2.4oz $240-on sale!
• 
  
• Magazine release: V Seven Weapon Systems Ultra-Light, hard coat Anodized. .2oz $31.58
• 
  
• Mag release Button: Strike Industries aluminum FDE $12.99 (the V Seven systems button is actually lighter but I wanted FDE)
• 
  
• Bolt Catch: Battle Arms Dev. Enhanced, Investment Cast. .4oz $13.16
• 
  
• Trigger Guard: B5 Systems Polymer. .2oz $7.50
• 
  
• Grip Screw: Badger Ordnance Titanium. .1oz $10.99
• 
  
• End Plate: Fortis Mfg. QD 6061-T6 Aluminum .3oz $8.99
• 
  
• Castle Nut: Fortis Mfg. Aluminum. .2oz $12.89
• 
  
• Safety: Strike Industries Flip Switch FDE .4oz $29.99 (this also comes with a cool round button to make it single sided but the weight is the same on my scale)
• 
  
• Grip: Hogue 15 Degree Polymer. .4oz weighed $16.96
• 
  
• Pivot and Takedown Pins: Strike Industries Ultra Light, Aircraft Aluminum. .2oz weighed $16.00
• 
  
• Buffer Tube Kit: Geissele, Premium Mil Spec Buffer Tube assembly w Super 42 spring and H2 buffer $110.99
• 
  
• -Buffer tube weight 3.7oz
• 
  
• -Super 42 spring 1.6oz
• 
  
• -buffer 3.2 oz w weight removed (not yet sure what the 6 ARC will need)

--I wanted to use my go-to Radian Talon safety but apparently it does not play nice with the SSA-E X trigger: Radian Talon-GI Single sided. .4oz $41.95 NOT COMPATIBLE W Geissele SSA-E X TRIGGER (wtf)​

---So that's the Lower as it stands. Of course it could be lighter with a carbon fiber stock but that cost saving allowed me to go ahead and purchase the following for the upper.

• Bear Creek Arsenal side charging upper receiver in 6 ARC. $163
• 
  
• Barrel: Faxon Gunner Profile 6mm ARC- 16" 1.57 pounds or 25.13oz $159.99
• 
  
• Hand Guard: Odin Works Rune Free Float M-LOK 12.4" 8.7oz w Nut. $99.20
• 
  
• Gas Tube: Spike's Tactical Melonited Mid-Length .73oz $12.96
• 
  
• Gas Block: Faxon.750 1.12oz $22.99

More to come!
Cheers,
Brian

 

[schmidty3]

Share more pics when it’s finished! I love retro ultralight builds. You may consider a slick side A1 upper to keep it even more simplistic if you’re a righty.

I almost did.

But the math said the standard A1 was $130 and the A2 was $80 . I think the slick side was more. Primary arms is a dangerous website.

I like the A2 sights better too.

The other issues is that its a middy barrel.

Im going to do an OG style handgaurd. But the carbine length handgaurds do look better.

 

[ProRoad]

UL 6mm ARC - Here is the nearly complete Roam lower with the BCA side charging upper and Faxon 16' barrel. It weighs in at 5 pounds 4.2 oz. This was my first time holding a rifle this light and I was quite surprised! It has some pretty light components as seen in the post above. (#4710) Below is a list of the upper parts. Now to find a SWFA Ultralight scope at 9.5oz....




Components of the upper:

• Bear Creek Arsenal side charging upper receiver in 6 ARC. 1 pound, 6.2oz! $163
• 
  
• Barrel: Faxon Gunner Profile 6mm ARC- 16" 1.57 pounds or 25.13oz $159.99
• 
  
• Hand Guard: Odin Works Rune Free Float M-LOK 12.4" 8.7oz w Nut. $99.20
• 
  
• Gas Tube: Spike's Tactical Melonited Mid-Length .7oz $12.96
• 
  
• Gas Block: Faxon.750 1.2oz $22.99
• 
  
• planned add on- Odin Works 4" ARCA rail $42

See post #4710 above for lower parts list and photos.

I asked my gunsmith if he would drill a hole for the BCA charging handle in a lighter bolt carrier group and he said no.. I know that some of you have done that which seems like a great weight saver. The BCA bcg weighs 1 pound, 6.2oz. yikes.

 

[ezwy]

UL 6mm ARC - Here is the nearly complete Roam lower with the BCA side charging upper and Faxon 16' barrel. It weighs in at 5 pounds 4.2 oz. This was my first time holding a rifle this light and I was quite surprised! It has some pretty light components as seen in the post above. (#4710) Below is a list of the upper parts. Now to find a SWFA Ultralight scope at 9.5oz....


View attachment 1075088

Components of the upper:

• Bear Creek Arsenal side charging upper receiver in 6 ARC. 1 pound, 6.2oz! $163
• 
  
• Barrel: Faxon Gunner Profile 6mm ARC- 16" 1.57 pounds or 25.13oz $159.99
• 
  
• Hand Guard: Odin Works Rune Free Float M-LOK 12.4" 8.7oz w Nut. $99.20
• 
  
• Gas Tube: Spike's Tactical Melonited Mid-Length .7oz $12.96
• 
  
• Gas Block: Faxon.750 1.2oz $22.99
• 
  
• planned add on- Odin Works 4" ARCA rail $42

See post #4710 above for lower parts list and photos.

I asked my gunsmith if he would drill a hole for the BCA charging handle in a lighter bolt carrier group and he said no.. I know that some of you have done that which seems like a great weight saver. The BCA bcg weighs 1 pound, 6.2oz. yikes.

You just need to chop your bcg in half.

 

[Taudisio]

You just need to chop your bcg in half.

Appears to be a gas gun

 

[ezwy]

Appears to be a gas gun

Ah. That would be a problem….

But explains the gas tube and such

 

[StupidLightweight]

Not a problem. Just chop the gas in half to match the carrier

 

[ProRoad]

Went out and shot about 10 or 12 rounds thru it. Every round had a jam (spent round jams against the incoming round) I tried 2 other lowers with various buffer spring weights, same issues so maybe its gas, maybe just needs a cleanup. Upon further shooting, eventually failure to extract from barrel on all of the last 6 or so rounds, had to use a rod to extract. So, I cleaned it at home and found that the extractor had broken off.. Classic BCA.

I will try my 22 ARC bolt carrier group in my 6 ARC (6.5 grendel-same specs) and try to isolate further issues. The Roam lower worked great with a different upper I tried so the BCA 6arc upper or bcg is the issue, whether its gas, bcg, extractor or dirty barrel. (check out that fine workmanship in the photos..... The 22ARC has less than 100 rounds and the 6ARC has about 10 or 12 rounds on the broken one.)

This is why I stayed gasser in the first place. When I build my side pull non-gasser, it will not be in 22 ARC or 6 ARC. (short case demons)

 

[Jesseb]

Went out and shot about 10 or 12 rounds thru it. Every round had a jam (spent round jams against the incoming round) I tried 2 other lowers with various buffer spring weights, same issues so maybe its gas, maybe just needs a cleanup. Upon further shooting, eventually failure to extract from barrel on all of the last 6 or so rounds, had to use a rod to extract. So, I cleaned it at home and found that the extractor had broken off.. Classic BCA.

I will try my 22 ARC bolt carrier group in my 6 ARC (6.5 grendel-same specs) and try to isolate further issues. The Roam lower worked great with a different upper I tried so the BCA 6arc upper or bcg is the issue, whether its gas, bcg, extractor or dirty barrel. (check out that fine workmanship in the photos..... The 22ARC has less than 100 rounds and the 6ARC has about 10 or 12 rounds on the broken one.)

This is why I stayed gasser in the first place. When I build my side pull non-gasser, it will not be in 22 ARC or 6 ARC. (short case demons)

Rexus bolt, all you need for Grendel based cartridges. Their complete bcg is pretty awesome too.

REXUS UltraBolt 6.5 Grendel | 6mm ARC | 22 ARC | 338 ARC AR15 Bolt

Best price on high-strength, strongest UltraBolt AR15 bolt for 6.5 Grendel, 6mm ARC, 22 ARC from Rexus Outfitters.

rexusoutfitters.com

 

[Jesseb]

Btw, if anyone has a BCA bolt action upper with arc/grendel bolt carrier for sale, I am in the market.