Ultralight Ultralight Rifles

[Taudisio]

As mentioned, you'll be fine with any 223 based case in the Solo 300 upper. I've taken deer, bears and hogs at well over 200 yards with the 223 and it works fine. Deer at over 300 and one bear at 350, no problems.

@Taudisio does really well shooting his 6x45 out past 500 yards and I have no doubt he could easily take all of the above at that range.

If you're handloading, another point to consider: If running 223 cases at 5.56 pressures, especially with a windowed magazine, they make up for some of the lesser case capacity compared to the ARC cases. Those run at considerably lower pressures in an AR platform, although those cases definitely handle the longer bullets much more easily at typical AR mag length.

Not able to reload and needing a 6mm could be tricky. I have seen options for a 25-45 sharps. Finding a barrel would be the tricky part, but definitely not impossible.

Edit to add

Ammunition

www.srcarms.com

Also adding that x-caliber barrels has a 25-45 sharps reamer.

 

[hereinaz]

Which bullet? I got some 75 Vmaxs to try (with your upcoming barrel!) - should be able to get them to 27-2800. Also got some 85 Speer BTSP...

I think it was the new varmint bullet from Hornady and ballistic tips. But, Vmax are probably similar.

Lemme see if I can’t find it, unless someone else chimes in.

 

[Thegman]

Some of you guys were talking about making right side chargers. I don't know if this would work for you as there are openings on both sides, but they're pretty cheap. 6061, so not ideal, but probably okay.

Davidson Defense AR-15 Side Charging Billet Upper Receiver - Anodized

mmcarmory.com

These are essentially a right side charging version of the earlier Solo upper (I have a couple of them). I don't know if those are 6061, but they work well.

 

[Sundodger]

Good to hear 300blackout works well in the solo upper, that would be a good option for blacktail, but I can't legally use .223 to hunt with in WA.

 

[Taudisio]

Good to hear 300blackout works well in the solo upper, that would be a good option for blacktail, but I can't legally use .223 to hunt with in WA.

I’m sure you can find a loader for 6x45 online. Mine worked fine on a short range, large blacktail last year. I’m sure I posted photos earlier in this thread. From what I’ve read, 300blk wouldn’t be in my top choices for what I like to do/how I hunt. I need the option to handle shots out to 400 yards and leaving a second rifle in the truck is a good way to lose it and a window around here.

 

[Thegman]

Which bullet? I got some 75 Vmaxs to try (with your upcoming barrel!) - should be able to get them to 27-2800. Also got some 85 Speer BTSP...

I was thinking that 85 Speer might be really good, and really inexpensive. The only drawback I see with Speer is their BCs seem to be way overstated, from my testing, anyway. The Speer BCs I've cross referenced with my Labradar have come out to about 0.7x to 0.87x what they're listed. The Hornady and Sierra have tested pretty much spot on to what they're listed (the 110 CX was the most off, but at least it was about 1.07x what they list it), the Nosler 125 BT was somewhere in between. Not as close as Hornady and Sierra, but not as far off as Speer.

I don't care about BCs as far as trajectory goes, but I do for minimum expansion velocity. According to my testing anyway, all the Speer bullets I've tested would hit that minimum velocity a lot closer in that what their listed BC would suggest.

 

[KyleR1985]

I was thinking that 85 Speer might be really good, and really inexpensive. The only drawback I see with Speer is their BCs seem to be way overstated, from my testing, anyway. The Speer BCs I've cross referenced with my Labradar have come out to about 0.7x to 0.87x what they're listed. The Hornady and Sierra have tested pretty much spot on to what they're listed (the 110 CX was the most off, but at least it was about 1.07x what they list it), the Nosler 125 BT was somewhere in between. Not as close as Hornady and Sierra, but not as far off as Speer.

I don't care about BCs as far as trajectory goes, but I do for minimum expansion velocity. According to my testing anyway, all the Speer bullets I've tested would hit that minimum velocity a lot closer in that what their listed BC would suggest.

@Taudisio

What did the 85 speers velocity look like down range?

Anyone know the min expansion velocity for them?

I would bet you can easily get 2700+ in 16” barrel. Maybe 2800

 

[Taudisio]

@Taudisio

What did the 85 speers velocity look like down range?

Anyone know the min expansion velocity for them?

I would bet you can easily get 2700+ in 16” barrel. Maybe 2800

I’d have to check my log book, but I think they have a longer bearing surface and gave me less velocity with a worse bc than the 87gr vmax so I dedicated my shooting towards the vmax. IIRC, they were 100fps slower with the same powder charge.

 

[KyleR1985]

I’d have to check my log book, but I think they have a longer bearing surface and gave me less velocity with a worse bc than the 87gr vmax so I dedicated my shooting towards the vmax. IIRC, they were 100fps slower with the same powder charge.

Dang. Well ignore my predictions on speed everyone

 

[PistolPete]

Some of you guys were talking about making right side chargers. I don't know if this would work for you as there are openings on both sides, but they're pretty cheap. 6061, so not ideal, but probably okay.

Davidson Defense AR-15 Side Charging Billet Upper Receiver - Anodized

mmcarmory.com

These are essentially a right side charging version of the earlier Solo upper (I have a couple of them). I don't know if those are 6061, but they work well.

These look chunky/heavy like the BCA uppers?

I was thinking that 85 Speer might be really good, and really inexpensive. The only drawback I see with Speer is their BCs seem to be way overstated, from my testing, anyway. The Speer BCs I've cross referenced with my Labradar have come out to about 0.7x to 0.87x what they're listed. The Hornady and Sierra have tested pretty much spot on to what they're listed (the 110 CX was the most off, but at least it was about 1.07x what they list it), the Nosler 125 BT was somewhere in between. Not as close as Hornady and Sierra, but not as far off as Speer.

I don't care about BCs as far as trajectory goes, but I do for minimum expansion velocity. According to my testing anyway, all the Speer bullets I've tested would hit that minimum velocity a lot closer in that what their listed BC would suggest.

I thought that same thing when I got these bullets - no way they're .380 BC!

 

[Thegman]

These look chunky/heavy like the BCA uppers?

I thought that same thing when I got these bullets - no way they're .380 BC!

I don't think they will be too heavy. They should be under 7 oz, easily, I think. I say that because the solos I have that are these Davidson Defense types are, I think, under 7 oz and these look identical in machining with even more cut away. I'll double check that weight, I want to make sure I'm not mixing it up with another upper.

Does Speer list that as .380? Probably around .300 at best I'd guess. Yesterday I tested a couple of my Speer 150 BTSP, like the 30 caliber version of the 6mm 85 grain. They list it as .417, it came out at .280 . The tips had been buggered up from recoil, so that was probably some of it, but that's a lot to account for. From what I've seen from Hornady bullets so far, the 87 VMax will hit .400 just like it's listed.

 

[Trackselk]

I don't think they will be too heavy. They should be under 7 oz, easily, I think. I say that because the solos I have that are these Davidson Defense types are, I think, under 7 oz and these look identical in machining with even more cut away. I'll double check that weight, I want to make sure I'm not mixing it up with another upper.

Does Speer list that as .380? Probably around .300 at best I'd guess. Yesterday I tested a couple of my Speer 150 BTSP, like the 30 caliber version of the 6mm 85 grain. They list it as .417, it came out at .280 . The tips had been buggered up from recoil, so that was probably some of it, but that's a lot to account for. From what I've seen from Hornady bullets so far, the 87 VMax will hit .400 just like it's listed.

I think they're about 10oz if I remember correctly. Good if you're going to run really hot loads I figure

 

[doverpack12]

Good to hear 300blackout works well in the solo upper, that would be a good option for blacktail, but I can't legally use .223 to hunt with in WA.

I have a bear creek 6 ARC 16” barrel on their side charge upper. Extraction is smooth and easy much easier than 300 Solo with Shaw 223 Wylde portless. 6 ARC Shoots 1” or better with Factory 108 ELDM. I’ve shot it at distance as well and had no issue hitting 8-10” gongs at 550 yards. No bipod just resting the pcc hand guard on something U shaped and good rear bags.

I think the bear creek upper in general has looser tolerances which aid in chambering and extraction.

I also put a 22 ARC Faxon barrel on the bear creek upper and cycling was a little more effort than 6 ARC but I think that is just a 22 ARC thing due to diameter of case compared to bullet. Still smoother and easier than solo 300/Shaw.

 

[Thegman]

These look chunky/heavy like the BCA uppers?

I thought that same thing when I got these bullets - no way they're .380 BC!

Just checked, the stripped Solo Davidson Defense type upper is 6.9oz. This one should be a bit lighter than that as there is a little more removed (port door/deflector provision is gone and cut out further back on the right side).

As long as they're stiff enough not to flex any appreciable amount, adding weight to an AR upper, especially a straight-pull, doesn't really help with strength relative to the loads one is firing (unless, I suppose, you blow it up). The firing pressure forces are contained by the bolt, barrel extension and barrel. The rest of the system is pretty much just a holder for those pieces and not exposed to those forces.

 

[Thegman]

I have a bear creek 6 ARC 16” barrel on their side charge upper. Extraction is smooth and easy much easier than 300 Solo with Shaw 223 Wylde portless. 6 ARC Shoots 1” or better with Factory 108 ELDM. I’ve shot it at distance as well and had no issue hitting 8-10” gongs at 550 yards. No bipod just resting the pcc hand guard on something U shaped and good rear bags.

I think the bear creek upper in general has looser tolerances which aid in chambering and extraction.

I also put a 22 ARC Faxon barrel on the bear creek upper and cycling was a little more effort than 6 ARC but I think that is just a 22 ARC thing due to diameter of case compared to bullet. Still smoother and easier than solo 300/Shaw.

Is that their side charger or bolt action upper?

My first side charger with a full mass YHM steel carrier and spring/buffer extracted okay with the 30HRT. That cartridge didn't work at all with the Solo, it was way to difficult to extract (as was the 6ARC). The barrel and bolt were exactly the same for both set-ups, the only difference I could see was the heavier, steel carrier vs. the much lighter shortened aluminum carrier. I was guessing the mass/inertia of the steel carrier was enough to break the case loose slightly under recoil, but less friction between the steel carrier and the cam pin vs. aluminum carrier and cam pin could be part of the equation as well.

 

[Sundodger]

I’m sure you can find a loader for 6x45 online. Mine worked fine on a short range, large blacktail last year. I’m sure I posted photos earlier in this thread. From what I’ve read, 300blk wouldn’t be in my top choices for what I like to do/how I hunt. I need the option to handle shots out to 400 yards and leaving a second rifle in the truck is a good way to lose it and a window around here.

If I were to build one in 300 blackout, it would be for the place I hunt blacktail which is all under 200 yards. Of all the deer we have killed there longest shot is about 125 yards.

For a 6mm build on the other hand, I would want something more in that 300-400 max range.

 

[doverpack12]

Is that their side charger or bolt action upper?

My first side charger with a full mass YHM steel carrier and spring/buffer extracted okay with the 30HRT. That cartridge didn't work at all with the Solo, it was way to difficult to extract (as was the 6ARC). The barrel and bolt were exactly the same for both set-ups, the only difference I could see was the heavier, steel carrier vs. the much lighter shortened aluminum carrier. I was guessing the mass/inertia of the steel carrier was enough to break the case loose slightly under recoil, but less friction between the steel carrier and the cam pin vs. aluminum carrier and cam pin could be part of the equation as well.

BCA side charge upper with their bolt and carrier. I cut the carrier off behind the firing pin. Forgot to weigh it but guessing upper with cut carrier and bolt is about 18 oz based on weight of other components I did get.

I also ran this gassed for over 100 rounds before converting to a repeater. Removing the gas rings and rubber plunger inside the extractor spring really smooths things out. Thegman, you suggested that for any bolt running as a repeater and it does make a big difference.

 

[Thegman]

BCA side charge upper with their bolt and carrier. I cut the carrier off behind the firing pin. Forgot to weigh it but guessing upper with cut carrier and bolt is about 18 oz based on weight of other components I did get.

I also ran this gassed for over 100 rounds before converting to a repeater. Removing the gas rings and rubber plunger inside the extractor spring really smooths things out. Thegman, you suggested that for any bolt running as a repeater and it does make a big difference.

That's really interesting to me. StupidLightweight's 6ARC worked with a cut down steel carrier as well in his upper, but it did not work in the Solo. I'm starting to wonder if the Solo extraction issue with ARCS etc. is more about the friction between the cam pin and cam pin track in the aluminum carrier??? Could test that idea with a cut down steel carrier with a left side handle in the Solo.

 

[Thegman]

If I were to build one in 300 blackout, it would be for the place I hunt blacktail which is all under 200 yards. Of all the deer we have killed there longest shot is about 125 yards.

For a 6mm build on the other hand, I would want something more in that 300-400 max range.

Blackout has worked well for me on deer at those ranges. Barnes 110 AAC should work well. If you can get some ammo loaded with Maker 110s, 125s, or Lehigh 115s it might be even better...

 

[Taudisio]

If I were to build one in 300 blackout, it would be for the place I hunt blacktail which is all under 200 yards. Of all the deer we have killed there longest shot is about 125 yards.

For a 6mm build on the other hand, I would want something more in that 300-400 max range.

Makes good sense to me. A 350 legend is another option for those ranges if you want to explore. I’d say whichever you could find cheaper ammo and barrel would be the best option. I’d assume the 300blk would have the better ammo selection.