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.

 

[Hardly_Hangin]

normally i might blame budget ammo being inconsistent but 5 on the chrono were very close. It was someone elses chrono they let me borrow while they were taking a break.

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

Between 30s and 3 minutes between each shot. I had a timer going to slow me down. Total was less than 30 rounds in an hour so averaged a shot every 2 minutes.

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.

Yeah, beats me. I dont remember the exact ft-lbs but i torqued the barrel nut halfway between the min and max recommended range (60ish?)

I probably missed it, but what optic are you using?

SWFA 2.5-10 on an aeroprecision cantelevered mount. The mount has blue loktight on threads connecting to the rifle.

Have you had someone else try to shoot it?

I havent, but thats a good idea.

That’s my step one. Check the Indian first, then mess with the bow. This Indian has been known to have some off days.

Im the indian that has to split and carry firewood while all my friends go kill wallhangers :') lol

 

[ezwy]

Well, I have only had a bolt action AR set up for a couple days, but I’m jonesin for a 6x45 barrel on another one. It sounds like satern and Shaw have been talked to. Would x caliber or black hole do a batch if we had 10 plus? Who should I bug about it?

I’m pretty happy with the Shaw in 223 wyld. I got a high tech optic as a gift, so it’s not exactly ultralight at the moment, but after a rough sight in I took it out to 300, 400 and then 550 yards on steel. Hit the 550 on my second shot.

 

[Hardly_Hangin]

Went back to the range again today to do a more controlled test. Both with 75gr AAC BTHP ammo off a very stable bench.

The first target is a 10 shot group at 50 yards waiting 3 minutes between shots, timed. After each shot i removed mag, opened chamber, and leaned it vertically hoping stack effect would cool barrel quicker.

Next target is all the same variables as the first, but i dumped the 10rd mag as fast as i could reaquire target.

I observe no difference in group size. Nobody else has shot the rifle for comparison.

Either i assembled something wrong or i guess maybe i got a dud? Does gas pressure affect accuracy?

Maybe ill try taking my flash suppressor off and see what that does. Eventually when my can gets out of jail ill have to repeat the whole process anyway.

Disappointed to say the least. Really wanted to have it done before season ends to shoot something.

 

[Thegman]

Before you try muc

Went back to the range again today to do a more controlled test. Both with 75gr AAC BTHP ammo off a very stable bench.

The first target is a 10 shot group at 50 yards waiting 3 minutes between shots, timed. After each shot i removed mag, opened chamber, and leaned it vertically hoping stack effect would cool barrel quicker. View attachment 806431

Next target is all the same variables as the first, but i dumped the 10rd mag as fast as i could reaquire target.
View attachment 806430
I observe no difference in group size. Nobody else has shot the rifle for comparison.

Either i assembled something wrong or i guess maybe i got a dud? Does gas pressure affect accuracy?

Maybe ill try taking my flash suppressor off and see what that does. Eventually when my can gets out of jail ill have to repeat the whole process anyway.

Disappointed to say the least. Really wanted to have it done before season ends to shoot something.

Before you try much else, it would be worth trying a couple different types of ammo. It could be simply that your rifle doesn't shoot this ammo very well, but might be fine with something else.

 

[goalie]

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

Sometimes a barrel doesn't shoot. If the scope and mount is good, and you've tried a bunch of different bullet weights and powders, I'd punt.

I lucked out with my Shaw. 10 rounds into two inches at 100 yards with a 3x micro prism is all I can ask for. And that's with AAC 77g OTM, I'll be loading for my hunting rounds

 

[Tailwind5sw]

I had a Bear creek barrel that would not stay on your target at 25yds. But the faxon pencil barrel was right on an inch. Some barrels don’t hold up.

 

[robtattoo]

I had a Bear creek barrel that would not stay on your target at 25yds. But the faxon pencil barrel was right on an inch. Some barrels don’t hold up.

 

[Trackselk]

Went back to the range again today to do a more controlled test. Both with 75gr AAC BTHP ammo off a very stable bench.

The first target is a 10 shot group at 50 yards waiting 3 minutes between shots, timed. After each shot i removed mag, opened chamber, and leaned it vertically hoping stack effect would cool barrel quicker. View attachment 806431

Next target is all the same variables as the first, but i dumped the 10rd mag as fast as i could reaquire target.
View attachment 806430
I observe no difference in group size. Nobody else has shot the rifle for comparison.

Either i assembled something wrong or i guess maybe i got a dud? Does gas pressure affect accuracy?

Maybe ill try taking my flash suppressor off and see what that does. Eventually when my can gets out of jail ill have to repeat the whole process anyway.

Disappointed to say the least. Really wanted to have it done before season ends to shoot something.

I'm tired right now as it's 1:15am, but verifying the scope on something that does shoot seems like a good idea, and then there's the possibility of pressure against the barrel, and probably a few more that I'm not thinking of. One of those plus a Terrible trigger on a light rifle and maybe you get those Terrible groups.
If scope tests good and mount is solid maybe bed the barrel like SLW mentioned? I don't think you're at the point of calling the barrel bad just yet...