Ultralight Ultralight Rifles

[Thegman]

He just threaded the steel 90 and added an aftermarket bolt knob. You could probably lengthen the gas key portion and maybe not even have to cutout the upper much (but risk punching yourself in the face).

View attachment 1028221View attachment 1028222View attachment 1028223

We talked about some ideas like this a couple of years ago, but none of us ended up going that direction.

A

Post in thread 'Ultralight Ultralight Rifles'

Jun 5, 2024

Saw this yesterday and it looks like a good option for these types of builds, they even offer a grendel bolt face so maybe it extracts well.

Straight pull

• ARK_Ginger

There was something from the apparently now-defunct Atl opp shop (above) like this, and the Kali-Key. I think @Taudisio was even talking with his gunsmith about something like this (???).

This is kind of a simplified version of the Kali-Key idea, with the bolt handle moved forward to actually make cycling more ergonomic. If I could source the handle, I'd gladly make one on an upper with a dremel. He's using the same NBS upper here as the original Solos were using. I think the mod would be easy to do with a dremel.

The main issue I see is keeping it in battery with just friction. He's not really demonstrating any real field use as one might see in hunting.

 

[Trackselk]

@Thegman
Might we be able to combine the Solo's detent ball setup with this?
The funny solution is to just use an appropriately sized rubber band

 

[Taudisio]

We talked about some ideas like this a couple of years ago, but none of us ended up going that direction.

A

Post in thread 'Ultralight Ultralight Rifles'

Jun 5, 2024

Saw this yesterday and it looks like a good option for these types of builds, they even offer a grendel bolt face so maybe it extracts well.

Straight pull

• ARK_Ginger

There was something from the apparently now-defunct Atl opp shop (above) like this, and the Kali-Key. I think @Taudisio was even talking with his gunsmith about something like this (???).

This is kind of a simplified version of the Kali-Key idea, with the bolt handle moved forward to actually make cycling more ergonomic. If I could source the handle, I'd gladly make one on an upper with a dremel. He's using the same NBS upper here as the original Solos were using. I think the mod would be easy to do with a dremel.

The main issue I see is keeping it in battery with just friction. He's not really demonstrating any real field use as one might see in hunting.

I totally forgot about that project. He still has my cheap upper and bcg. We discussed it and he drew it up. It’s been a long time though and I’m sure it has slipped his mind too. I have him working on 2 other projects that I’d prefer to be done haha

 

[Thegman]

@Thegman
Might we be able to combine the Solo's detent ball setup with this?
The funny solution is to just use an appropriately sized rubber band

That would probably work okay, although due to the increased mass of the bolt handle, it might drop out of battery more easily when bounced around vertically, like when slung on your shoulder (???). Maybe not though.

I've thought of a few other ways to have it lock up, but have been pretty happy running the Solos as is.

 

[Bearded Gnome]

TheGman did you notice the thread count at 4,444 in your response? There is a lot of interest in advancements, but good old experimentation as well. I am using this thread as inspiration to make a few builds. Normally it would be about one ULUL but I got the itch. I have parts for six rifles, one being a gasser in 358 but the rest in the usual range of .223s and a Hamm'r. Thanks for the spark. Be Well Brothers, BG.

 

[Trackselk]

That would probably work okay, although due to the increased mass of the bolt handle, it might drop out of battery more easily when bounced around vertically, like when slung on your shoulder (???). Maybe not though.

I've thought of a few other ways to have it lock up, but have been pretty happy running the Solos as is.

Yeah, that's a good point on the mass, and a bigger handle is more likely to hang up on brush. I'll probably stick with the Solo also, although I did take a look at it and looks like we could attach it over the top of the existing detent setup, just need 2 longer screws. It'd be thin enough that it might require steel construction.
I also like to sling it on my back, and my minimalist bolt handle doesn't dig into me, which is why I made it so tiny. A bigger handle would make me have to sling it over my back left handed which isn't as easy to redeploy. FWIW

 

[Bearded Gnome]

Gman, how do you go about loading the Ham'r with LC cases? Just wondering about the whole process. I have some 5.56 cases processed for .223 Remington. Where to go from there? TIA; The Bearded Gnome.

 

[Trackselk]

Yeah, that's a good point on the mass, and a bigger handle is more likely to hang up on brush. I'll probably stick with the Solo also, although I did take a look at it and looks like we could attach it over the top of the existing detent setup, just need 2 longer screws. It'd be thin enough that it might require steel construction.
I also like to sling it on my back, and my minimalist bolt handle doesn't dig into me, which is why I made it so tiny. A bigger handle would make me have to sling it over my back left handed which isn't as easy to redeploy. FWIW

Actually, I think I'm smoking something, the bolt points outboard slung on the back for a righty, and this new bolt idea we're talking about affords the option of being on either side. Off to see how much those uppers cost that don't have the big slot cut...
As well as mine stays in battery I'm not too worried, but I haven't even pulled the spring(s?) Yet. I also haven't cycled it more than maybe 50-100 times. Just some thick red grease.
Conversely anyone could implement this mod on their Solo and then just pull it if it doesn't work out. Cheap experiment even if you had to buy a dremel.
Edit: this has me thinking again about the magnesium uppers that Packgoatguy uses. I decided against them due to cutting the large slot in an already reportedly weak upper (i read of at least one of them breaking) didn't sit well with me and my hot reloads. But, a tiny slot opposite the boom, that should be fine, especially since PGG's upper has been doing fine with the very warm UM or BH loads anyhow, unless that has changed? @packgoatguy

 

[Thegman]

Gman, how do you go about loading the Ham'r with LC cases? Just wondering about the whole process. I have some 5.56 cases processed for .223 Remington. Where to go from there? TIA; The Bearded Gnome.

It's pretty straightforward, but a couple of things to do to maximize success. The biggest issue is split necks when doing initial case forming.

Cut the 223/5.56 case down as close as possible to final 300 HAM’R length as step one. The less neck you're expanding the less chance the case mouth will split. This alone cuts split necks way, way down.

I anneal the cases after cutting before forming to further reduce split cases and soften what will become the 300 HAM’R shoulder. You don't have do a perfect annealing job, but softening the brass some seems to help.

Lube the body and inside the neck and size. I sort of tap the case through the expander rather running it straight through to further reduce split necks.

I leave the sizing die backed out a little and test a case to be sure I'm not forming the shoulder too far down for a particular chamber. Size that case shoulder down a bit at a time until the case is just past a crush fit. Form another case and make any final adjustments. By case three you should have the die set perfectly for you chamber and can start producing.

 

[Trackselk]

Before I do something crazy, is there any reason that the magnesium upper, or just about any upper for that matter won't work for this 'rear strait pull' design?

 

[Thegman]

Actually, I think I'm smoking something, the bolt points outboard slung on the back for a righty, and this new bolt idea we're talking about affords the option of being on either side. Off to see how much those uppers cost that don't have the big slot cut...
As well as mine stays in battery I'm not too worried, but I haven't even pulled the spring(s?) Yet. I also haven't cycled it more than maybe 50-100 times. Just some thick red grease.
Conversely anyone could implement this mod on their Solo and then just pull it if it doesn't work out. Cheap experiment even if you had to buy a dremel.
Edit: this has me thinking again about the magnesium uppers that Packgoatguy uses. I decided against them due to cutting the large slot in an already reportedly weak upper (i read of at least one of them breaking) didn't sit well with me and my hot reloads. But, a tiny slot opposite the boom, that should be fine, especially since PGG's upper has been doing fine with the very warm UM or BH loads anyhow, unless that has changed? @packgoatguy

It would definitely be worth trying.

Here's you upper to start with.

NBS Slick Side Billet Upper Receiver

The NBS Slick Side Billet Upper Receiver is a quality, American made billet upper featuring a unique design that sets it apart from traditional forged upper receivers. Manufactured to exacting standards on five axis CNC machines from a solid block of aircraft grade aluminum, this stripped upper...

ar15discounts.com

 

[Trackselk]

It would definitely be worth trying.

Here's you upper to start with.

NBS Slick Side Billet Upper Receiver

The NBS Slick Side Billet Upper Receiver is a quality, American made billet upper featuring a unique design that sets it apart from traditional forged upper receivers. Manufactured to exacting standards on five axis CNC machines from a solid block of aircraft grade aluminum, this stripped upper...

ar15discounts.com

Thanks! Maybe it's in there, but is the detent ball void already present in those? If not the Solo is the only way as far as I'm concerned. Maybe Solo would sell me one without the handle cutout(?)

 

[StupidLightweight]

Before I do something crazy, is there any reason that the magnesium upper, or just about any upper for that matter won't work for this 'rear strait pull' design?

Go for it with whatever upper you prefer. I cut a slit in my polymer upper and it has held up for 6+ years. Personally, i'd start with a forged slickside 9mm upper, but that's just me.

As for the ball detent, I've never needed one in my straight-pull builds. The friction of the bolt in battery and magazine tension on the carrier holds things just fine. To ensure it won't open, go hammer down on an empty chamber.

 

[Trackselk]

Go for it with whatever upper you prefer. I cut a slit in my polymer upper and it has held up for 6+ years. Personally, i'd start with a forged slickside 9mm upper, but that's just me.

As for the ball detent, I've never needed one in my straight-pull builds. The friction of the bolt in battery and magazine tension on the carrier holds things just fine. To ensure it won't open, go hammer down on an empty chamber.

Thanks! That's more weight loss without the (steel?) Detent ball and arm. What makes you choose that 9mm upper? I'd definitely like to go with a light press fit (barrel) for more precision, I'm hoping that's what you'll say. Do you know of a good make by chance?

 

[Thegman]

Thanks! Maybe it's in there, but is the detent ball void already present in those? If not the Solo is the only way as far as I'm concerned. Maybe Solo would sell me one without the handle cutout(?)

That cut-out is part of the AR upper design that Solo co-opted for the detent ball, so yes, it's there.

 

[Trackselk]

That cut-out is part of the AR upper design that Solo co-opted for the detent ball, so yes, it's there.

Good deal, thanks again. It's nice to have the option if it's popping open!

 

[Trackselk]

I'm thinking about a Roam magnesium upper @ 4.3oz ($300). Anybody have any experience with them? Before I buy, I'm going to take the file to the Solo and see how light I can get it, but last I looked I guessed I'd only get about an 1 oz shaved off. Maybe I can do some lightening cuts with the router as well.