Ultralight Ultralight Rifles

[9.3koolaid]

Yeah… I think I’m going to try a Warne mount. I had the worst time trying to level the scope in this mount due to the torque it was applying

It's pretty annoying after the third try haha

 

[Thegman]

I received my complete KP-15 receivers today, and am impressed with how beefy they feel while still being lightweight. Skeletonizing the rifle might be tough, the inside of the buttstock is mostly hollow, with ribbed sections on the top and bottom to add strength and probably provide extra mating surfaces for the vibration welding used to connect the left and right sides of the receiver.

The recoil pad was lightweight and mostly hollow, as was the grip. I was surprised to find it was hollow with reinforcing ribs when I ran a 1/2" bit inside to see if I could get rid of some plastic.

I swapped the buffer for Taccom ULW delrin buffer (1.1oz), swapped the mag release, hammer, and trigger out for New Frontier Armory polymer parts.

Weights:

• As received, full assembly: 27.7oz
• Buffer: 2.8oz
• Recoil pad w/screws: 1.3oz
• Modified, full assembly: 23.9 oz

I installed a 16" Faxon 6mm ARC barrel, with their 10" carbon fiber handguard, on an Aeroprecision upper, with a lightweight Brownells bolt that I picked up on sale earlier this year (Memorial Day sale?). Total weight with a magazine came to 4lb 14.5oz. Lightweight, but not ultralight at all. An Aeroprecision scope mount will add 3.4 oz more, and if I add a 6x SWFA (likely), it will end up a chunky ~6lb 6.5oz.... plus a suppressor....

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Looks like it will work really well; 4lb 14.5oz is still a nice lightweight rifle.

 

[4090Sharps]

It's pretty annoying after the third try haha

It was more than three....

 

[40tude]

Solo 300 uppers are back on the website…

 

[StupidLightweight]

Boy, it pays to be the only maker of bolt-action AR uppers. For what you get from Solo 300 — a receiver and chopped carrier — $275 is nuts. Then again, I guess it pays to be the only maker....

I had a chat with Shaw Custom Barrels today about bolt-action AR barrels. They plan to release an ultralight .223 barrel without a gas port for us weirdos. To my knowledge, they will also be the only maker. Let's hope the price is decent. When I get mine in a few weeks, I'll share the intel.

 

[Bigwindymt]

This is quite interesting, all but the 223 cal bullets. 375/458 socom would be wild in this application, and you would definitely be chasing far fewer blood trails.

 

[StupidLightweight]

This is quite interesting, all but the 223 cal bullets. 375/458 socom would be wild in this application, and you would definitely be chasing far fewer blood trails.

The best part of bolt-action ARs is you can easily go this route. On my bolt-action uppers, I can just spin the handguard off and swap barrels, which is pretty cool. It's the ultimate takedown rifle.

For me, these builds are a balance between weight, ballistics, and recoil. I went .300 BLK on my lightest ever pistol build (image below), which weighs a bit over 2 pounds. Let me tell you, recoil is brutal. A .458 in this weight class would destroy shoulders.

All that said, out to 200 or so yards — about as far as I can accurately shoot ultralight ARs — the 5.56/.223 is no joke. With the right bullet, I'd use it without reservations where .22-cal bullets are legal for big-game.

 

[Thegman]

Thanks for the info on the Shaw barrels; that will be interesting.

I don't know about a 458 Socom at this weight. Would probably be a bit much for me personally, and the 223 77 TMK seems to be no joke. All three deer this week dropped immediately when hit and tumbled down the mountain. These two were right at and a bit over 300 yard shots. The Red Ryder is proving it's worth.

 

[Bigwindymt]

Anyone use a Bear Creek side charger?
The specs have them pretty heavy on there site but that includes a full gas system and forearm.
For $200ish, maybe worth a try??

I did this w/ an 8.6 blackout build. They will not just sell the upper and bcg. If anyone else goes this route, test fire before messing with the parts. Mine was out of spec! There aren't really any other options in the AR 10 platform though. I'd do the solo 300, if I was going AR 15.

 

[Brontosaurus]

Thanks for the info on the Shaw barrels; that will be interesting.

I don't know about a 458 Socom at this weight. Would probably be a bit much for me personally, and the 223 77 TMK seems to be no joke. All three deer this week dropped immediately when hit and tumbled down the mountain. These two were right at and a bit over 300 yard shots. The Red Ryder is proving it's worth.

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Nice work!! Post those in the 223 thread if you haven't already!

 

[Bigwindymt]

.458 in this weight class would destroy shoulders.

Brake or suppressor! Go subsonic with the 458 and still shoot out to 150yds. I know people kill moose with .223, but .338 and larger calibers just kill so much more quickly, without having to destroy the shoulders.

 

[Bigwindymt]

The handguard on the 6mm ARC straight pull is from Wiland USA. According to them, the 10-inch version with barrel nut weighs 5.3 ounces. It's designed for PCCs, so it won't work with a gas system. Not a problem on these builds, obviously.

That handguard is decently priced too! I pieced one together for my lightweight gas gun with a 7075 al barrel nut, length of carbon fiber tube from ebay, and an external aluminum clamp for nearly the same price. And that doesn't count my work cutting and drilling the tube and turning the barrel nut down to fit!

 

[40tude]

That handguard is decently priced too! I pieced one together for my lightweight gas gun with a 7075 al barrel nut, length of carbon fiber tube from ebay, and an external aluminum clamp for nearly the same price. And that doesn't count my work cutting and drilling the tube and turning the barrel nut down to fit!

It does fit over a trimmed gas block fwiw.
Thanks

 

[Oakridge]

This forum is expensive. Any reason I can’t build one of these in 350 legend? Looking to use a solo 300 upper. Should be a perfect light build for brush hunting straight wall states.

 

[StupidLightweight]

This forum is expensive. Any reason I can’t build one of these in 350 legend? Looking to use a solo 300 upper. Should be a perfect light build for brush hunting straight wall states.

.350L would be an excellent straight-pull build. A cool feature about that cartridge is how quiet the report is. I'm not claiming hearing safe, but from a 16-inch barrel, the .350 is far quieter than the crack of a .223.

 

[Oakridge]

.350L would be an excellent straight-pull build. A cool feature about that cartridge is how quiet the report is. I'm not claiming hearing safe, but from a 16-inch barrel, the .350 is far quieter than the crack of a .223.

Would there be any issue with extraction due to straight wall? Sorry for my ignorance. I just have zero experience with straight pull ar’s

 

[JCMCUBIC]

.350L would be an excellent straight-pull build. A cool feature about that cartridge is how quiet the report is. I'm not claiming hearing safe, but from a 16-inch barrel, the .350 is far quieter than the crack of a .223.

I've found this to be very true to my ears.

The difference in a .358 Win and .243 Win is very noticeable to me, even with hearing protection.

 

[StupidLightweight]

Would there be any issue with extraction due to straight wall? Sorry for my ignorance. I just have zero experience with straight pull ar’s

Truthfully, I have zero experience with .350L straight-pulls, but I think it would be fine. Other members said .223-based rounds were all easy to extract. I know there's a huge difference between my .300 BLK (mostly straight-wall) and my 6mm ARC builds. The 300B is so easy to cycle compared to the ARC.

 

[Oakridge]

Well looks like I’ll start ordering part! Thanks man!

 

[Thegman]

My first straight pull AR was a 350 Legend. It cycled fine but that wasn't a Solo build. I've not tried it on a Solo yet. So...most likely, yes, but on the 30 HRT I did notice an extraction difference between that full mass carrier straight pull (same as I used with the 350) and the Solo build...so I guess that's a -maybe- not. IDK either.

When I get time in the next couple of weeks I'll throw that 350 barrel on a spare Solo and let you know how it functions.