Problem child barrel

[BillB]

Well, I dont think hes in the business of making crap barrels, he has a fanatical following and believe it or not I emailed him during my lunch today hoping to reserve a 12.5" barrel that's due some time in October. So no, I dont think he is doing bad business. $#!+ happens, I understand that and have no I'll will towards the man, if I did I sure as hell wouldn't be trying to get another one.

The just of my OP was simply to ask if the copper deposits on top of the lands was normal, I've never seen it happen, it's always along the edges down in the grooves or just a wash of copper filling in the roughness in the grooves, maybe some at the muzzel. And if this copper in the obviously very rough lands could be causing the poor accuracy and extreme flyers I get constantly.

[BillB]

I'm not sure if there is a "gold standard" 6.8 loading but I have shot some Hornady 110gr BTHP loads through it, but some cheap bulk H and higher end 110gr V-max load and their 100gr GMX loading and basically the same result. So, I dont know. I'm no reloading genius but I only use a single stage, take my time, prep is king, quality components. a multitude of powders, bullets and seating depths. S&B cases sized for my chamber minus .004". Been using Lee dies but just bought a set of RCBS to see but I've always had Lee dies for other calibers and had success with them. Anything is possible though I guess.

[Coal Dragger]

If both decent quality factory ammo, and carefully assembled reloads aren’t working then there’s probably not much to be done.

The fact headspace is a bit excessive is a big red flag that there is something wrong. Some barrel makers have issues with salt bath nitride barrels and barrel extensions, depending on the procedures used when assembling them it’s possible the barrel and barrel extension to loosen from specified torque.

Good luck.

[NWcityguy2]

The just of my OP was simply to ask if the copper deposits on top of the lands was normal, I've never seen it happen, it's always along the edges down in the grooves or just a wash of copper filling in the roughness in the grooves, maybe some at the muzzel. And if this copper in the obviously very rough lands could be causing the poor accuracy and extreme flyers I get constantly.

I honestly don't pay attention to copper fouling enough to say yes or no. I tend to notice it by the muzzle myself. To me, it seems like a good question for ARP.

[Glacierwolf]

I am a reloading instructor and former US Coast Guard National Shooting team member. I do not usually post - way too much AR reloading dis-information. Usually from bolt gun shooters.

400rds. Your barrel and new upper is barely broken in. Sounds like you have done right so far. The key to your issues - those flyers - you get a nice group going - X,10,X,10,X and then one shows in the 7 ring. Assuming the barrel nut is 35ftlbs (I have gone to 87ftlb to get the right fit and that rifle was a tack driver) and you are a competent marksman this is always and ammunition issue. Go buy a coaxial concentricity gauge and check your ammo. In EIC matches were ammo is issued I will quickly run all the ammo - .000" to .003" true are my 600yd slow fire, .004" to .008" are my 300yd, .009" to .015" are 200yd slow fire. Anything past .015" become sighters. I have found Lake City Match at .027" and got a Federal Gold Medal that was .047". Saved those as training aids.

Your ammo has to be totally identical from round to round. I teach people to process all their brass in batches. This way you have a pool of 500 or so rounds that even if something is a tad kittywampus they are all kittywampus the same way. All brass with the same headstamp. Then you sit down with primed brass, cal the scale - and spend the rest of day assembling rounds. Digital scale+powder measure will make the job much easier and more accurate. You want RCBS match dies - or just buy the match seating die since you have the other. That match die will make sure the bullet is aligned with the brass to make your ammo all in the .000" to .015". It will also let you adjust each round so they are identical length. This is another important metric - identical COL. Longer rounds are going to have a shorter jump to the lands and grooves. Shorter ones get more of a running start at the rifling - and will come out faster, and faster means it hits a tad higher.

Another tool to consider. Chronograph - you want to see all those rounds come out at nearly the same speed + or - 30fps for 600yd competition. I have made loads that were 2.1fps for 10 rounds. You get them to all come out the barrel the same speed and still have those flyers - then you look at concentricity issues.

Me? I would loan you a chronograph first to check speed and everyone was coming out the the barrel at the same fps. Fix that first. Then match dies to kill those really big flyers. Then the coaxal gauge to put your ammo into groups.

Hope this helps.
Kevin M

[Fast Pat]

I think something is loose. Either the barrel or the scope/mounts if so equipped.

[BillB]

Nope, checked both and both were tight, loosened, torqued to spec, again.

I bought a borescope and I'll post pics or a video later.