Ultralight Ultralight Rifles

[Thegman]

This is the spring that keeps the lugs pushed outwards right?

I'm not totally sure what you're referring to, but I think, yes. It's the spring that is installed at the tail of the bolt, in the bolt carrier. It pushes the bolt forward, and the carrier rearward. If it pushes the carrier back enough, the carrier will unlock the bolt and pull the bolt rearward via the cam pin.

Let me know if you need any help accessing the spring.

 

[Trackselk]

I'm not totally sure what you're referring to, but I think, yes. It's the spring that is installed at the tail of the bolt, in the bolt carrier. It pushes the bolt forward, and the carrier rearward. If it pushes the carrier back enough, the carrier will unlock the bolt and pull the bolt rearward via the cam pin.

Let me know if you need any help accessing the spring.

Thanks, you got it. My anatomy of AR's still sucks...

 

[Trackselk]

Has anyone built an ultralight version of the Kifaru gun bearer?

I haven't heard of any, but after running the kifaru/stone glacier hybrid which works best, I missed having a sling, and once I got my rifle down to 4 pounds, my ultralight sling was actually comfortable (1" ultralight webbing). So, I did away with the awkward carrier and just stuff the rifle in the day pack at the end of daylight. Probably TMI, but after many miles in mixed terrain that's what I found works best, YMMV

*That hybrid setup is pretty light but expensive

 

[Thegman]

Has anyone built an ultralight version of the Kifaru gun bearer?

I did, years ago, with some miscellaneous straps I had. I used it for bolt rifles a lot, but have never used it for one of these. FWIW, it worked very well, but once I started using a pack frame I could hang a rifle sling on, I stopped using it.

 

[proslogion]

I somehow keep ending up in the longest threads on the forum!

I've never seen a reason to own an AR, but this thread has me obsessing. Really cool work done by everyone.

I know it has been mentioned a month or so ago - but I e-mailed TNArms about their Carbon TN15 for an eta on restock, but I haven't heard back (for anyone curious). It sounds like their poly lower is only slightly heavier, so that isn't a bad option.

 

[proslogion]

Or you could just pull the barrel extension, and make an insert, and not require a gunsmith….thats a Satern 6x45 AR barrel in a handi rifle stub.

No gunsmith, just a dude who stayed at a holiday inn express!View attachment 820811

Did you ever do a write-up on this rifle?

I tried looking through threads you created but didn't see anything.

 

[Sundodger]

Took my new solo 300 to the range for the first time this weekend, and it’s having some extraction issues.


After firing it takes so much force to cycle the action that I have to put the pistol brace on the ground with the barrel pointing up and smack the bolt handle with a mallet to move the bolt a bit back, then I can cycle it with my hand. Cycles fine empty.

I have heard this is common with Grendel based cartridges, but this is a 300 blackout.


Any ideas where to start my trouble shooting?

Any chance this caused from my suppressor?

Factory cheap supersonic ammo, but it was very humid out.

Was just reading this thread:

Thread 'Pressure signs from suppressor?'

Feb 23, 2026

I just got my first suppressor (Unknown Reaper) and went out to rezero with my same hand loads I’ve been using the past 900 or so rounds on my gun, felt a slightly sticky bolt towards the end of the 10 round zero. After this I waited a couple min and went into a shooting drill and after a couple shots I started getting sticky bolt that progressed to heavy bolt lift and I stopped, ejector swipe on my brass.

Next day I went out to see if removing the can when I started to get sticky bolt lift would remedy this. I shot a 10 round string, waited approx 2 min then started another string...

• WoolyBugger
• Replies: 81
• Forum: Suppressors

 

[Thegman]

Any chance this caused from my suppressor?

Factory cheap supersonic ammo, but it was very humid out.

Was just reading this thread:

Thread 'Pressure signs from suppressor?'

Feb 23, 2026

I just got my first suppressor (Unknown Reaper) and went out to rezero with my same hand loads I’ve been using the past 900 or so rounds on my gun, felt a slightly sticky bolt towards the end of the 10 round zero. After this I waited a couple min and went into a shooting drill and after a couple shots I started getting sticky bolt that progressed to heavy bolt lift and I stopped, ejector swipe on my brass.

Next day I went out to see if removing the can when I started to get sticky bolt lift would remedy this. I shot a 10 round string, waited approx 2 min then started another string...

• WoolyBugger
• Replies: 81
• Forum: Suppressors

Could be, part of it at least; would definitely increase back pressure. That said, there are lots of guys running suppressors on these with no issues, and the 300 BO is about the easiest extracting cartridge one can chamber in one of these.

Try firing without the suppressor, obviously, and see what happens, but I'd think there's probably some other issues going on. Ammo, chamber, extension or bolt issues, or some combination thereof. Kind of hard to say without more information.

 

[Trackselk]

Could be, part of it at least; would definitely increase back pressure. That said, there are lots of guys running suppressors on these with no issues, and the 300 BO is about the easiest extracting cartridge one can chamber in one of these.

Try firing without the suppressor, obviously, and see what happens, but I'd think there's probably some other issues going on. Ammo, chamber, extension or bolt issues, or some combination thereof. Kind of hard to say without more information.

Could be, part of it at least; would definitely increase back pressure. That said, there are lots of guys running suppressors on these with no issues, and the 300 BO is about the easiest extracting cartridge one can chamber in one of these.

Try firing without the suppressor, obviously, and see what happens, but I'd think there's probably some other issues going on. Ammo, chamber, extension or bolt issues, or some combination thereof. Kind of hard to say without more information.

I'd add a perfect layer of scotch tape to the cartridge face and see if it's then more difficult to extract without firing. I'm guessing you don't have enough headspace. If you reload you could bump the shoulder progressively further back to check. If you don't reload you might be able to fix it with a different bolt. I bet gunsmiths have a better fix.

 

[Trackselk]

I got a Sharpe's Relia-Bolt on order. Hopefully this will help with chambering 223/5.56 rounds in my now 223ai barrel for fireforming. The camming action of the lugs sounds like it might help, plus they're much stronger insurance for my hot reloads. Mainly getting tool steel bolt for its strength.

-has anyone tried these in a strait-pull?

"Improved Cycling: The Relia-Bolt features uniquely designed, curved camming lugs that help reduce friction and binding, making the manual, straight-back-and-forward motion of a custom straight-pull AR-15 smoother and more reliable.
Reduced Friction/Binding: By using S7 tool steel and a self-lubricating NP3 coating, the bolt reduces the chance of jams during the manual chambering process."

 

[Thegman]

I got a Sharpe's Relia-Bolt on order. Hopefully this will help with chambering 223/5.56 rounds in my now 223ai barrel for fireforming. The camming action of the lugs sounds like it might help, plus they're much stronger insurance for my hot reloads. Mainly getting tool steel bolt for its strength.

-has anyone tried these in a strait-pull?

"Improved Cycling: The Relia-Bolt features uniquely designed, curved camming lugs that help reduce friction and binding, making the manual, straight-back-and-forward motion of a custom straight-pull AR-15 smoother and more reliable.
Reduced Friction/Binding: By using S7 tool steel and a self-lubricating NP3 coating, the bolt reduces the chance of jams during the manual chambering process."

I haven't, but was considering trying one. Let us know what you think of it.

FWIW, I don't recall that description for use in a "custom straight-pull" back when I looked into these. Literally sounds like they've been reading this thread...

 

[Trackselk]

I haven't, but was considering trying one. Let us know what you think of it.

FWIW, I don't recall that description for use in a "custom straight-pull" back when I looked into these. Literally sounds like they've been reading this thread...

Will do. I was thinking of going back and noting that that was from google AI so all bets are off on its accuracy...

 

[Sundodger]

Could be, part of it at least; would definitely increase back pressure. That said, there are lots of guys running suppressors on these with no issues, and the 300 BO is about the easiest extracting cartridge one can chamber in one of these.

Try firing without the suppressor, obviously, and see what happens, but I'd think there's probably some other issues going on. Ammo, chamber, extension or bolt issues, or some combination thereof. Kind of hard to say without more information.

I'd add a perfect layer of scotch tape to the cartridge face and see if it's then more difficult to extract without firing. I'm guessing you don't have enough headspace. If you reload you could bump the shoulder progressively further back to check. If you don't reload you might be able to fix it with a different bolt. I bet gunsmiths have a better fix.

I put a layer of scotch tape on an unfired round from the same box I was shooting last weekend and was having this problem. Chambered fine, the second piece of scotch tape and it didn’t.

I should probably go buy some 300 black out go/no go gauges. If that checks out maybe I’ll buy a box of not quite the cheapest ammo in the store…

Emailed solo Monday and still haven’t heard back, which isn’t my favorite.

 

[Trackselk]

I put a layer of scotch tape on an unfired round from the same box I was shooting last weekend and was having this problem. Chambered fine, the second piece of scotch tape and it didn’t.

I should probably go buy some 300 black out go/no go gauges. If that checks out maybe I’ll buy a box of not quite the cheapest ammo in the store…

Emailed solo Monday and still haven’t heard back, which isn’t my favorite.

Hmm, shouldn't be a headspace issue from the sounds of it. A rough chamber is another thought, and I'd buy a few different boxes of different brands of ammo to get a better read on it

 

[Sundodger]

Hmm, shouldn't be a headspace issue from the sounds of it. A rough chamber is another thought, and I'd buy a few different boxes of different brands of ammo to get a better read on it

I need to run my borescope though it and get some footage.

Was also thinking of trying subsonic ammo. If it struggles to extract with subsonic ammo and no suppressor I can probably rule out pressure.

 

[Bearded Gnome]

Give the chamber a light cleaning. Split a dowel rod of a generously small size compared to the chamber. Into the split slide a bit of OOOO steel wool. Oil the chamber generously and spin the wool in the chamber on the dowel. Clean the chamber thoroughly. Clean it again with a spray solvent in a safe spot. I use brake cleaning spray. IT IS DANGEROUS STUFF. The fumes are wicked and it will "MELT" plastic. Sorry to sound like Dad but it is truly wicked stuff. But it works on most metals. I use it to clean the bore when at the outdoor range. It cleans the bore of fresh carbon and cools the barrel between groups. Be Well Brothers, Bearded Gnome.

 

[Trackselk]

Give the chamber a light cleaning. Split a dowel rod of a generously small size compared to the chamber. Into the split slide a bit of OOOO steel wool. Oil the chamber generously and spin the wool in the chamber on the dowel. Clean the chamber thoroughly. Clean it again with a spray solvent in a safe spot. I use brake cleaning spray. IT IS DANGEROUS STUFF. The fumes are wicked and it will "MELT" plastic. Sorry to sound like Dad but it is truly wicked stuff. But it works on most metals. I use it to clean the bore when at the outdoor range. It cleans the bore of fresh carbon and cools the barrel between groups. Be Well Brothers, Bearded Gnome.

Funny, I've been thinking about a high polish for my new 223ai barrels. Do you use a drill for this, and is this one of the ways to get a highly polished chamber? Lastly, how do you avoid touching/damaging the lands?

 

[Bearded Gnome]

I don't go into the neck but a tiny bit. If the neck is needing it I have to make up a neck size setup to spin a smaller piece of 4/0 steel wool with corresponding holder. One can overdo this thing fast. Lots of oil and don't get aggressive. You are just taking a rough spot out. If you scope it you may know where you are looking to smooth it. I had a 22 Hornet barrel reamed to the KHornet. The guy told me to do this method as his reamer had a flute/tooth broken. It looks rough after the steel wool but the loads don't stick. So It worked. But I know I could have gone too hard and ruined the chamber. It was in a Contender barrel so it was easy to access. A rifle barrel not so much. but at least it can be accessed by pulling a pin. Slightly better than a conventional bolt gun. Good luck and be Well Brother, BG.

 

[PistolPete]

I got a Sharpe's Relia-Bolt on order. Hopefully this will help with chambering 223/5.56 rounds in my now 223ai barrel for fireforming. The camming action of the lugs sounds like it might help, plus they're much stronger insurance for my hot reloads. Mainly getting tool steel bolt for its strength.

-has anyone tried these in a strait-pull?

"Improved Cycling: The Relia-Bolt features uniquely designed, curved camming lugs that help reduce friction and binding, making the manual, straight-back-and-forward motion of a custom straight-pull AR-15 smoother and more reliable.
Reduced Friction/Binding: By using S7 tool steel and a self-lubricating NP3 coating, the bolt reduces the chance of jams during the manual chambering process."

Wonder if this fancy strong bolt would allow 6 ARC bolt gun pressure loads in a BCA bolt upper? Hmm

EDIT Nevermind, no ARC bolts. Still seems cool, and my Solo is also pretty tough to cycle/close fully, so I'm still interested in how it goes.

 

[Sundodger]

Trying to sort out my extraction issue on my solo 300 in 300 black out.

Scoped the chamber, saw a few rough spots, so decided to remove the barrel and polish it up with some bronze wire brush.

Scoped it after the polish, not perfect, but better.

Took it too the range and extraction was better, but not great. First few shots it took more effort than I wanted to eject a case, but technically worked. Once it started warming up it got worse. Only needed a mallet to tap it out of battery once which is a huge improvement, but still pretty unacceptable. Coupled times I pulled hard enough to get it out of battery that the extractor let go of the case rim before the case could eject, leaving the empty case on top of my mag.

Letting the gun cool for about 15 min, it was back to extracting like it did when I first got to the range (not great, but good enough).

What do you guys think? Anything else to try before I send this thing back to solo 300? Not sure a second or third polishing is going to completely fix this.

Before polishing:

After polishing: