Ultralight Ultralight Rifles

[Jesseb]

Another vote for Larue MBT-2S flat face. That’s all I run in my AR’s anymore. I 3D printed a spacer for my ulul to move the face forward .300” for a more comfortable fit with the scrawny hogue grip. Just stuck it on with spray adhesive. I much prefer a 2 stage in the AR platform for hunting/precision purposes. Never found the Geiselle’s did anything better besides drain my bank account.

 

[KyleR1985]

Another vote for Larue MBT-2S flat face. That’s all I run in my AR’s anymore. I 3D printed a spacer for my ulul to move the face forward .300” for a more comfortable fit with the scrawny hogue grip. Just stuck it on with spray adhesive. I much prefer a 2 stage in the AR platform for hunting/precision purposes. Never found the Geiselle’s did anything better besides drain my bank account.

Want to print spacers to go in the upper where the bolt catch/release would go, since it's not needed with the straight pull?

I would pay 5 bucks for it.

 

[Jesseb]

I should also clarify that the 2900 fps I saw with 77 tmk and Lever turned out to be a fast lot of powder from 2014. I ran a ladder with a 2021 lot and got 2829 with 26.3 grains and 2796 with 26.6 indicating I hit some kind of pressure spike. I still do not believe the older lot was higher pressure. All pressure signs look identical. If anything the older lot was more consistent without the odd speed spikes. Problem is I can’t go back to 2014! 8208 xbr is looking like it will still be the winner. Probably gonna end up in the 2725-2750 range.

 

[Jesseb]

Want to print spacers to go in the upper where the bolt catch/release would go, since it's not needed with the straight pull?

I would pay 5 bucks for it.

I can, but if it were me, I would grab an epoxy putty stick in grey or black color and mix up a bit and stuff it in there and shape it to fit. JB steel stick, HF, ACE, etc are a nice grey color. Black can be ordered off amazon if you can’t find it locally. You might even get away with 5 minute regular JB weld and just kinda keep shaping it as it starts curing. Sharpie also turns just about anything black right quick.

 

[Sundodger]

Thanks for the trigger suggestion guys, couple of questions:

I am surprised at how heavy most aftermarket AR triggers are, light weight ones seem to be advertised in the 3.5-4.5lbs with only a few options below that. All of my bolt guns are in the 2-3lb range, any idea why AR's triggers tend to be on the heavier side? Is there a reason for this?

I am relatively green to the AR world, but what is the reason there being so many 2 stage triggers vs bolt rifles where it's pretty rare?

Any opinions of the CMC single stage trigger? They sell it in a 2.5lb version and it's only $110.

 

[JBradley500]

A kid I know built a 308 ar10 with a light single stage to hunt deer with. He was bump firing all of the time. He thought something was wrong, but it was just the recoil combined with the short reset caused the issue. That's just one story, but it made me less of a believer in that setup in semiauto.

 

[Jesseb]

Thanks for the trigger suggestion guys, couple of questions:

I am surprised at how heavy most aftermarket AR triggers are, light weight ones seem to be advertised in the 3.5-4.5lbs with only a few options below that. All of my bolt guns are in the 2-3lb range, any idea why AR's triggers tend to be on the heavier side? Is there a reason for this?

I am relatively green to the AR world, but what is the reason there being so many 2 stage triggers vs bolt rifles where it's pretty rare?

Any opinions of the CMC single stage trigger? They sell it in a 2.5lb version and it's only $110.

It’s a function of the design of the AR trigger and hammer. Single stage triggers tend to have a noticeable creep, really no way around it. With the 2 stage you are getting an easy 2lb-ish first stage and then that crisp break at another 2lbs-ish. You really don’t even notice the first stage and get a lot less creep. The first stage essentially takes the creep out of the way. With the AR you are releasing a hammer to strike a floating firing pin. With a bolt gun you are releasing a spring loaded firing pin. I suppose one could adjust and or smith the creep out and lower the spring weight a bit for one of these bolt action AR builds since it is no longer auto. The hammer spring is part of this equation though and not easy to get around without risking light strikes. No bueno for a hunting gun imho. I tried 2 and 3lb single stage triggers and came back to the 2+2lb 2 stage.

Edit: just tested the mbt-2s on my ulul. 1.75lb 1st stage and second stage breaks at 3.5lb

 

[packgoatguy]

Looking for a trigger for my lightweight AR build, what do you guys like?

Not afraid to spend a little money, but love a good value too.

I like a crisp, single stage, that can be adjusted to 2ish lbs.

With you guys building ultralightweight rifles I figured you guys will have good triggers figured out.

Recommendations?

I like the cheap poly trigger that comes with the NFA polymer lpk. Had a Giselle on there before... and I can shoot it just as well with the poly... but for more than an ounce weight savings. This is the ultralight-ultralight thread after all LOL

 

[Thegman]

Thanks for the trigger suggestion guys, couple of questions:

I am surprised at how heavy most aftermarket AR triggers are, light weight ones seem to be advertised in the 3.5-4.5lbs with only a few options below that. All of my bolt guns are in the 2-3lb range, any idea why AR's triggers tend to be on the heavier side? Is there a reason for this?

I am relatively green to the AR world, but what is the reason there being so many 2 stage triggers vs bolt rifles where it's pretty rare?

Any opinions of the CMC single stage trigger? They sell it in a 2.5lb version and it's only $110.

I have a CMC single stage and it's a nice trigger, with a couple of caveats.

In order to get it to fit in the TN Arms lower, I had to take the trigger apart and sand down the bottom of the trigger housing. I don't blame that on the trigger though, that's most likely an issue with the polymer lower.

The second issue was that the trigger pull was heavier than the stated weight. CMC was very good about taking care of that and got it running at the advertised weight.

All said though, I'd take my modified-spring Schmid over that trigger (and as stated, the NFA polymer trigger seems to work pretty darn well for what it is). Mine have enough initial creep to simulate a 2S, most of the time...

 

[PistolPete]

Sorry to break up the trigger talk, but I'm doing a 6x45 barrel group buy:

Thread 'ULUL Stainless/Portless 6x45 16" AR15 Barrel Group Buy NOW CLOSED'

May 28, 2025

***UPDATE: THIS GROUP BUY IS NOW CLOSED***

With blessing from @hereinaz who had this idea, I'm going to move forward with a group buy for the above barrel. Dimensions will be similar to the Shaw but ~0.020" larger to account for the 6mm barrel, 16.5", 1:8 twist. This will be to fit bolt action AR15 "ultralight ultralight" rifles described in other threads.

I'm not interested in making money, or risking money, so I'll need to collect it beforehand. I'm also not interested in much tweaking of this design, since this is what I want, ha. If you have any suggestions I'll listen, of...

• PistolPete
• Replies: 79
• Forum: Firearms

• 
• 

Thought some may be interested!

 

[Sundodger]

This lightweight AR build will be a straight pull bolt action, but you guys are making me think about going with a 2 stage trigger.

I am still having a hard time with how heavy these triggers are; 2ish lbs for a first stage and another 2ish lbs for the second. I have bolt guns twice the weight and half the trigger pull. Maybe I need to go shoot one, but the idea that the first stage is about what I am used to for an entire trigger is hard sell especially in such a light rifle.

Most of the bolt gun guys I know (including myself) would throw a fit about a 4-6lb trigger, what am I missing?

 

[Megastink]

I want to build a ULUL bolt gun in 6x45. I have a 9# 6x45 now, but it sucks hiking up and down these PA hills with it. If I can get around 6# scoped (SWFA Ultralight), I'd be really happy.

 

[Megastink]

Sorry to break up the trigger talk, but I'm doing a 6x45 barrel group buy:

Thread 'ULUL Stainless/Portless 6x45 16" AR15 Barrel Group Buy NOW CLOSED'

May 28, 2025

***UPDATE: THIS GROUP BUY IS NOW CLOSED***

With blessing from @hereinaz who had this idea, I'm going to move forward with a group buy for the above barrel. Dimensions will be similar to the Shaw but ~0.020" larger to account for the 6mm barrel, 16.5", 1:8 twist. This will be to fit bolt action AR15 "ultralight ultralight" rifles described in other threads.

I'm not interested in making money, or risking money, so I'll need to collect it beforehand. I'm also not interested in much tweaking of this design, since this is what I want, ha. If you have any suggestions I'll listen, of...

• PistolPete
• Replies: 79
• Forum: Firearms

• 
• 

Thought some may be interested!

If they'd toss in a savage prefit with the same specs, I'd be down. Cant deer hunt with an AR here in PA *yet*

 

[Thegman]

This lightweight AR build will be a straight pull bolt action, but you guys are making me think about going with a 2 stage trigger.

I am still having a hard time with how heavy these triggers are; 2ish lbs for a first stage and another 2ish lbs for the second. I have bolt guns twice the weight and half the trigger pull. Maybe I need to go shoot one, but the idea that the first stage is about what I am used to for an entire trigger is hard sell especially in such a light rifle.

Most of the bolt gun guys I know (including myself) would throw a fit about a 4-6lb trigger, what am I missing?

Personally, I don't think you're really missing anything. Like @Taudisio says, the Trigger Tech 1S Diamond trigger would probably be the most precise, but the difference between a light 2S probably isn't much. Might not even be any difference. My Larue MBT isn't as light as everyone else's, apparently, but I think my re-sprung Schmid would give any 1S a run for its money.

 

[The Guide]

If they'd toss in a savage prefit with the same specs, I'd be down. Cant deer hunt with an AR here in PA *yet*

It isn't an AR persay. It is made with no gas port and has to be manually operated. Doing it this way it is a straight pull, slide action repeater with no Semi-auto functionality.

Jay

 

[Taudisio]

I want to build a ULUL bolt gun in 6x45. I have a 9# 6x45 now, but it sucks hiking up and down these PA hills with it. If I can get around 6# scoped (SWFA Ultralight), I'd be really happy.

That’s easily achievable. Follow the steps! I’m a little over 4lbs loaded, suppressed, scoped. And like @The Guide says, I would dig into your laws. You couldn’t make a non-ported ulul barrel into a gas rifle without significant changes.

 

[robtattoo]

Well, I've decided to switch out barrels to 6x45 & I know.... no sales.... but if anyone is in the market for a blocked port, 16" pencil profile Wilson Combat, stainless .300 Ham'r barrel, along with a set of 3 Lee dies, 100 bits of brass & +/- 420 125/130gr bullets; hit me up for a price!
No splitting up. It's going as a ready to go package deal.

 

[Jesseb]

Anyone know if Primary Arms does a good 4th of July sale? Trying to decide if I should jump on the current sale or wait for 4th of July to grab a 5x microprism.

 

[Taudisio]

Anyone know if Primary Arms does a good 4th of July sale? Trying to decide if I should jump on the current sale or wait for 4th of July to grab a 5x microprism.

They usually run a sale for every holiday. I forget which sale I got mine at but it was 15% off and I got 20% back in store credit. It was enough to buy the steel target from their shop the I use a lot.

 

[gtriple]

I just got an open box one for $250 pre tax.