Like any self respecting firearm enthusiast I always have some number of projects going on concurrently.  One of them is a fast twist 22-250 bolt gun.  

Every once in a while Tikka makes a run of 22-250 T3x rifles with 1-8” twist barrel and I happen to have one.  That dramatically changes the varminty character of the 22-250. With a modern 80gr bullet, it is a nicely viable hunting rifle for small and medium game (just about perfect for pronghorn).  It is also a very capable long range number.  At the altitude where I live, it does not go subsonic until you get to about 1400 yards.

1-8” twist will not stabilize the heaviest available 22 bullets, but works well enough for anything up to about 80grains, depending on the bullet construction.

Since my ultimate goal with competition is to shoot NRL Hunter matches in an Open Light class (to more closely resemble the rifles I actually hunt with), I set up my 308Win Fix and 6.5PRC Stag Pursuit for Open Light and Factory respectively.
I have a lot more 308Win ammo than 6.5CM anyway, so that is the rifle I prefer to practice with.

Now that I have a little time before the next Hunter match, I decided to see if I can properly control the muzzle rise with the lighter rifles.  To that extent, I went and sighted them in before proceeding with shooting at various plates mostly between 500 and 600 yards to see if I can control the  muzzle well enough to spot my misses.

The wind was pretty sporting and inconsistent today.  On top of that, I decided to use the lightweight pint-sized gamechanger bag to add to the challenge.  While we were at it, I also tested the new tripod plate from Sunway photo.  I generally like it, but it needs to be a bit wider for shooting purposes.  It is great for holding binos and a wind meter.

Here is how the bag fits on it:

Not bad, but a little more width would help.  The tripod is Field Optics Research's Dome Top Hunter 32.

The 308 Fix is a known quantity since I have talked about it quite a lot in the past.  In this iteration, I have it set up with Tangent Theta 5-25x56 in an Aadmount. 

The muzzle device is Q's Bottle Rocket on top of a Cherry Bomb.  

The bipod is Gunwerks' Elevate.

Rather amazingly, the balance on this thing is just right as is.

However, I must have made a miscalculation somewhere because I thought this would weigh just a hair below 12lbs.  It weighed in at exactly 11lbs and based on the Arizona match, my scales measure a little higher than the ones they used over there (about 5 ounce difference for my 6.5CM gun).

Despite that, I had no real issues controlling the muzzle rise with this setup.  I was able to comfortably spot my shots and see trace as long as I was properly square behind the rifle.  Interestingly, at this weight, it is something I might actually hunt with, but a lighter scope might not be a bad idea.

This also means that I have enough weight budget to use Q's Trash Panda suppressor instead of the Bottle Rocket brake.  While the brake is not obnoxiously loud, I do prefer to run with a suppressor when possible, so I will try that next.  

With the 6.5PRC, I know for a fact that without a decent brake, I could not spot my own shots, so I have Area 419's titanium Hellfire brake on it.  This was my first time shooting with it.

It was substantially loud, but not as obnoxious as some competition brakes I have seen.  More importantly, muzzle rise was minimal at most.  I doubled up on the hearing protection, but the rifle became impressively more mild mannered.  Again, shooting standing off of a tripod in the wind, I had not problem at all spotting my own shots and watching trace when shooting a bit further out.

The rifle is Stag Pursuit in 6.5PRC

The scope is Vortex Razor HD-LHT 4.5-22x50 in Talley MSR rings (the lightest 30mm rings I had on hand).

The bipod is Gunwerks' Elevate.

As shown, the rifle clocked in at 11.7lbs on my scales.  I am inclined to not mess with it too much, but if it comes to that, I can mount a somewhat heavier scope without too much trouble, but I am inclined to let it be.

I did a good number of dry presses and live fire with both rifles.  One thing that surprised me a little was that the Fix had a smaller wobble zone than the Pursuit.  I think I can attribute that to the balance point on the Fix being a little further forward, but some experimentation is in order.

I was definitely shooting better with the Fix, despite the Pursuit being chmabered for a much flatter cartridge.  Perhaps, a heavier bipod will shift the balance point sufficiently.

That is one of the advantages of the Fix design: the buttstock, while sturdy and comfortable, is so light that it is very easy to balance.  Pursuit's beefy buttstock while comfortable, could use some weight cutting.  If I want to ever use this rifle for NRL Hunter's Factory division, I can not make any mods, so I'll do with what I have.  If my arithmetic is correct, I could probably get a lightweight Ckye-pod to shift the weight a little forward.

With all that, I am not sure how I feel about trying to game this too much.  For now, I'll just shoot the rifle as is and see if I can train my way out of this wobble zone issue with some deliberate practice.

I have to admit that Area 419's muzzle brake is pretty impressive.  The rifle is now extremely soft shooting and the muzzle stays down.

The next step for the 6.5PRC is to either buy or work-up some proper match ammo.  All I have is Hornady's 143gr ELD-X which shoots pretty well in this gun, but isn't match ammo.

Hornady loads their 147gr ELDM in 6.5PRC, so that is probably the first option to try.  Looking at the costs, this might be one of the few calibers I have to reload for.

If I were to go compete with a sub-12lbs rifle today, I think I would still take the 308 Fix despite all the ballistic disadvantages.  It is probably just the familiarity factor, but I simply shoot that rifle better.  In the future... we'll see how it goes.

At this point, I do not remember any more how I stumbled on this barrel, but it is not unusual for me to be looking for relatively random things while I can't sleep at night.
Then again, given how much time I spend at the range, looking at different AR barrels is not all that random.
My take on AR-15s is that they are supposed to be lightweight and accurate enough to reach to the outer limits of the capability envelope of whatever they happened to be chambered for.  I know they are plenty of people out there with freakishly accurate AR-15s that are set up with thick barrel.  They are impressively consistent, but a heavy AR-15 sorta defeats the purpose of an AR-15 to me.
Then again, I do have a couple of moderately heavy small frame AR variants.  One is built around an 18" 223Wylde WOA barrel and the other around a 22" Satern 224 Valkyrie barrel.  I'll talk about those builds in due time and I enjoy shooting both of those rifles quite a bit.  However, I view them as practice rifles since 5.56 and 224V are nice practice rounds for longer range stuff and it is easier to balance heavy barrel rifles for shooting off bags.
Most of my ARs are a lot lighter than that and they are built around 16" barrels of moderate weight.
Ideally, I want this rifle to weigh no more than 8lbs with a scope, typically an LPVO of some sort.  This is the type of rifle I expect to be equally comfortable doing timed short range drills and shooting plates between 600 and 800 yards (with appropriate ammo).
Over the years, you have seen pictures of several of these variants.  One of my favourites is built around a 16" Proof Research carbon fiber barrel.  That's the AR in this video:

I have another one built around an experimental 16" barrel that is sleeved in AlSiC, a rather exotic material.  That way of making barrels did not go into production, unfortunately.  It is not the most intrinsically accurate barrel I have, but it is very well behaved when hot.
Naturally, I also have a couple that simply have thin, near-pencil profiles.
The basic problem with most of the light weight barrels I have seen to date, is what happens when the barrel heats up.  Most barrels end up with substantially larger groups when hot, which is OK.  However, quite a few of them end up with the group centroid also changing, sometimes significantly, which is not OK.
That is an especially commo problem with carbon fiber wrapped barrels.  Christensen barrels are famous for their wandering zero.  Proof Research barrels seem to be better and the two I have do not wander around when warmed up.  However, it appears that some do.  With carbon fiber wrapped barrels I tested, Proof was the best, but it has been a little while since I experimented with it.  More recently, I have heard from others that Helix6 and Bartlein barrels are more consistent, but heavier. 

Most lightweight barrels designed for light weight have an odd (to me) profile with too much metal removed by the chamber.  Some years ago, Adams Arms had their own pencil profile barrel that left a lot more metal near the chamber, then went thing quickly.  The way Q does their light weight barrel is also done with heat distribution in mind.  Their barrel leave a lot of metal near the chamber, then run what is essentially a straight taper.

All this barrel research is probably how I stumbled onto the Trident Barrel from X2 Devgroup https://x2devgroup.com/trident-barrel/

It has very deep flutes which dramatically cuts weight.  It is about five ounces lighter than my carbon fiber Proof barrel of the same length.  Fluting can often cause problems when not properly stress relieved, but it seemed like they were paying attention to this kind of stuff and taking care to not introduce stress.  After digging through my memory banks a little, I remembered that a know someone at that company.  It was time to pick his brain.  He is a pretty serious shooter, and he was happy with these barrels.  Then he said something that made me perk up and pay attention.  He talked about vibration and how these barrels felt "dead".  That is a lot of the same verbiage I hear about structured barrels from TacomHQ.  Once my interest was properly peaked, I looked around, relaized I have enough spare parts to build an upper and that I have a built up AR-15 lower that is not attached to anything.

Once the barrel got here, I gave it a careful look.  In terms of the quality and consistency of the machining, it looked very good.  Those are some seriously deep flutes though.

The barrel, somewhat unusually, is dimpled for both of the gasblock screws and in a way that will work with the majority of gas blocks out there.

I had an Aero upper and an Aero handguard of relatively ghastly color, that probably explains why it was heavily discounted.  Since I fully expect it to be scratched up and covered by dust before too long, I could not care less.

I plan to run it with and without a suppressor, so I added Q's Cherry Bomb compensator to it.  As this is written, I have not fired it yet, but will shotly.  After some consideration, I decided to mount March's excellent 1.5-15x42 MPVO on it. https://alnk.to/b7zh0YQ  That is still the purest expresssion of the MPVO concept on the market today, so I thought it was appropriate.  Depending on how it performs, March may or may not stay on there permanently.  However, for initial break in, long range practice and accuracy evaluation, it knocks the socks off of any and every LPVO ever made.

Most AR-15s are reasonably broken in somewhere between 200 and 500 rounds, so I am not going to stress about accuracy too much in the beginning.  I'll get it sighted in, do some positional shooting and keep an eye on whether there is any abnormal behavious.

The rifle ended up weighing a bit under 6lbs without optics and a bit under 8lbs with March 1.5-15x42 in Burris XTR Signature rings. https://alnk.to/4MBZHCL The suppressor will push it a hair over 8lbs, but that's close enough.  With the bipod as pictured it just under 9lbs.  The bipod is not going to be on there permanently.  If I have to choose between a suppressor and a bipod for weight reasons, Jumbo Shrimp it is  https://alnk.to/880ol8Y

Eventually, I will likely switch to a lighter LPVO on this gun since I prefer the March on a hunting rifle, but in the meantime, configuration-wise, it is a near perfect SPR.

The nice thing about all these AR variants is how easy they are to accessorize, but all those extra gadgets do add weight.  For example, if I throw Steiner's excellent C35 v2 clip-on on there, it is another pound. https://alnk.to/8iV9jU9

An offset red dot sight will not add much weight, but it still adds a little.  Same goes for the light/laser (I think I have an extra CMR-301 https://alnk.to/880olc5 somewhere here that I can use.  It is not super fancy, but it works).

Before it is all said and done, if I keep everything on there, I will end up with am 11.5 to 12 lbs gun.  It sounds like a lot and it is.  However, if I did not start with a sub-6lbs gun before everything that I plan to latch onto it, we'd be talking about a 15lbs setup.  That's why I want a truly accurate sub-6lbs AR-15 and that is why I am always on this "holy grail" barrel search.

Stay tuned for the updates as I test this thing.