Ultralight Ultralight Rifles

[BREAKCONTACT]

What OD CF tube did you use?

I may try a glue in like @goalie + Farrow tech.

I 3d printed a mold and did a wet layup with carbon fiber fabric. If you want to use a tube and plate, I would get a 28mm ID tube with around a 2mm wall thickness. The max milspec for rifle reciver extensions is 1.115", which is just a hair over 28 mm, you might have to wrap sand paper around a socket to bore it out a hair for a tight fit. And I would get 3mm plate for the buttplate.

 

[Trackselk]

I 3d printed a mold and did a wet layup with carbon fiber fabric. If you want to use a tube and plate, I would get a 28mm ID tube with around a 2mm wall thickness. The max milspec for rifle reciver extensions is 1.115", which is just a hair over 28 mm, you might have to wrap sand paper around a socket to bore it out a hair for a tight fit. And I would get 3mm plate for the buttplate.

The wall thickness of the tube I used is 1.1mm as per my calipers, and it's plenty strong. Might save you an ounce+.
Total with the buffer tube stub and forrowtech glued together is 3.2 oz.

 

[jaws4951]

Might be off the mark here but looking myself for more of a lightweight hunting build...Anyone try the Outlier Modular Chassis? Seems like it would be super light. Was thinking of having it set up with a MDT Composite Carbine Stock and want to put a 7 PRC barrel on it. Have a Remington 783 LA currently chambered in 7mm Rem Mag. Outlier/Arken barrels seem fairly inexpensive too. Apologies if this is off the mark but wanted to see if anyone has any input/experience with Outlier.

 

[JBradley500]

Finished my lightweight gasser build last night, quite a handy piece of plunder. Could definitely shave some weight off if i decide to go lighter (bcg, handguard, buffer tube, stock and optic could reduce weight significantly, but this is mybstarting place). Being my first ar built it was pretty satisfying going from a box of parts to a gun.

However, my 16.5" faxon barrel is grouping horrendously at 50 yards. How much time are you guys allowing between shots to cool with these thin barrels? I sampled a medly of ammo from 55gr fmj to 77gr aac tmk and none of it grouped worth a flip. The barrel was super hot the whole time, i could see mirage through the handguard. I shot roughly 100 rounds in about an hour.

is there anything i could have screwed up during assembly that would affect accuracy? How many rounds to "break in"? Or do i just need to take a chill pill ad slow down?
View attachment 805014

I have a 16" faxon pencil and I can hammer rounds through it, like 15 in a row and there is no noticable shift.

 

[packgoatguy]

Might be off the mark here but looking myself for more of a lightweight hunting build...Anyone try the Outlier Modular Chassis? Seems like it would be super light. Was thinking of having it set up with a MDT Composite Carbine Stock and want to put a 7 PRC barrel on it. Have a Remington 783 LA currently chambered in 7mm Rem Mag. Outlier/Arken barrels seem fairly inexpensive too. Apologies if this is off the mark but wanted to see if anyone has any input/experience with Outlier.

No experience with outlier... but i like what they are trying to do... but it is still going to be heavier than the lightest options out there.

By my math, id estimate that the final chassis will be at least 25.5oz (assuming you went with a 3oz minimalist buffertube stock setup like has been noted in this thread) and the lightest pssible CF grip like the mdt one at 1oz
(per their website)
16.96oz (chassis)
4.6oz (shortest foregrip)
3oz (minimalist buffertube stock)
1oz mdt CF grip

If you want ultralight, the mdt hnt26 chassis is the one to beat... if you ditch their stock, replace with a buffertube adapter and minimalist buffertube stock, you can get it to under 20oz.

 

[jaws4951]

No experience with outlier... but i like what they are trying to do... but it is still going to be heavier than the lightest options out there.

By my math, id estimate that the final chassis will be at least 25.5oz (assuming you went with a 3oz minimalist buffertube stock setup like has been noted in this thread) and the lightest pssible CF grip like the mdt one at 1oz
(per their website)
16.96oz (chassis)
4.6oz (shortest foregrip)
3oz (minimalist buffertube stock)
1oz mdt CF grip

If you want ultralight, the mdt hnt26 chassis is the one to beat... if you ditch their stock, replace with a buffertube adapter and minimalist buffertube stock, you can get it to under 20oz.

This is helpful, thank you.

 

[packgoatguy]

Shaved nearly half an ounce off of a Hogue 15degree grip... its now only 1.4grams heavier than the MDT CF grip, for a fraction of the price.

 

[Hardly_Hangin]

Cold bore groups much better today. Final 9 shot group was after 10 or so unpictured shots. Tried to wait a minute or so between shots. Still need one more trip hopefully to verify zero and get a good 10rd group

75gr aac bthp

 

[Trackselk]

Cold bore groups much better today. Final 9 shot group was after 10 or so unpictured shots. Tried to wait a minute or so between shots. Still need one more trip hopefully to verify zero and get a good 10rd group

75gr aac bthp
View attachment 805948View attachment 805949View attachment 805952View attachment 805954

Just to clarify, the last 9 had no cool down in-between shots?

 

[KyleR1985]

Finished my lightweight gasser build last night, quite a handy piece of plunder. Could definitely shave some weight off if i decide to go lighter (bcg, handguard, buffer tube, stock and optic could reduce weight significantly, but this is mybstarting place). Being my first ar built it was pretty satisfying going from a box of parts to a gun.

However, my 16.5" faxon barrel is grouping horrendously at 50 yards. How much time are you guys allowing between shots to cool with these thin barrels? I sampled a medly of ammo from 55gr fmj to 77gr aac tmk and none of it grouped worth a flip. The barrel was super hot the whole time, i could see mirage through the handguard. I shot roughly 100 rounds in about an hour.

is there anything i could have screwed up during assembly that would affect accuracy? How many rounds to "break in"? Or do i just need to take a chill pill ad slow down?
View attachment 805014

Something is off.

I’ve had the BCA pencil barrel, Shaw pencil barrel, and faxon 6ARC barrel in my two builds. Nothing has shot over 2moa through factory or hand loaded pressure and velocity checking random stuff. Hot and cold. Fast and slow.

I’m not a good shot.

I did torque my barrel nuts pretty tight though.

Don’t take shooting or loading advice from me. But, it’s a good data point that if I can get them to shoot you can, for sure.

 

[Taudisio]

Cold bore groups much better today. Final 9 shot group was after 10 or so unpictured shots. Tried to wait a minute or so between shots. Still need one more trip hopefully to verify zero and get a good 10rd group

75gr aac bthp
View attachment 805948View attachment 805949View attachment 805952View attachment 805954

I probably missed it, but what optic are you using? Have you had someone else try to shoot it?
That’s my step one. Check the Indian first, then mess with the bow. This Indian has been known to have some off days.