A little help figuring it out

[dag52]

[LRRPF52]

Welcome aboard. I'll have to break this down, since we are dealing with no less than 8 different variables.

Shooting experience/background?
Is the upper receiver face squared?
Is the barrel bedded into the upper?
Is the scope leveled?
What scope mount are you using?
Are the scope mount bolts and ring fastener screws balanced in torque value?

Did you dry-fire until you were comfortable with the reticle not jumping off the diamond?

[NugginFutz]

Welcome, Dave!

With respect to the carbon on your cases, there are a few things you didn't mention:

Which Buffer and spring are you using?

How is your gas block set? (Barely locking back the bolt, WFO or something in between?)

Do you clean the sizing lube from the cases prior to loading and seating or firing? (Some reloaders do not)

Did you happen to notice where the brass was landing when shooting factory vs. your loads?

[dag52]

Welcome aboard. I'll have to break this down, since we are dealing with no less than 8 different variables.

Shooting experience/background?
Average shooter, hunting, plinking etc. No military or organized training. I shoot pistol more than rifle.

Is the upper receiver face squared?
I did not even check, just purchased from a reputable manufacturer.

Is the barrel bedded into the upper?
No, I have read various things about Loctite bedding and decided against it for now. Barrel extension to receiver fit was decent, but not perfect. I would guess about .001 - .002 slop.

Is the scope leveled?
Yes

What scope mount are you using?
Burris Pepr QD, yes it's tight and has not been dismounted since mounting the scope.

Are the scope mount bolts and ring fastener screws balanced in torque value?
Yes

Did you dry-fire until you were comfortable with the reticle not jumping off the diamond?

Yes

A little more about my range time...
I was using a Caldwell LeadSled to eliminate shooter issues. It was absolutely rock steady on the target, much better than I could manage on my own. My plan was to find out what the rifle could do, before seeing what "I" could do.

Thanks for the quick follow-up!

Dave

[dag52]

Welcome, Dave!

With respect to the carbon on your cases, there are a few things you didn't mention:

Which Buffer and spring are you using?
The lower is not dedicated to this rifle, it came of my CQB AR, until I can afford to get a matching Vltor Lower. I'm not sure what buffer or spring are in there, as they are not marked, but it is off of a carbine length gas system rifle.

How is your gas block set? (Barely locking back the bolt, WFO or something in between?)
While breaking in the barrel, I set it to just lock open on an empty mag, but I opened it up another half turn when I noticed the case mouth getting dinged pretty good. It now ejects at 4:00 and no denting of the case mouth.

Do you clean the sizing lube from the cases prior to loading and seating or firing? (Some reloaders do not)
Yes. My methodology is, deprime (dedicated decapping die), clean with ultransonic, lube, size, clean, prime, seat.

Did you happen to notice where the brass was landing when shooting factory vs. your loads?

It looked like the Hornady factory loads would end up about 3:30, compared to my handloads at 4:00, but it was not a huge difference. The Horandy loads did group quite a bit higher on the target, about 2.5". Leading me to believe that they were running considerably faster, but without a chrono, it's just a guess.

[dag52]

Sorry about the weird "half quote", "half reply" thing...

Dave

[Klem]

G'day Dave, and welcome.

Interested in the carbonised cases
Any chance of posting a photo of these carbonised-neck cases?
Was the carbonising the same extent across all your reloads or graduated, with more carbon from the lower loads and less from the higher loads?
Is the gas setting generously open or tuned to lock back on last round?

[dag52]

Klem,

It seemed pretty consistent across the 40 rounds I shot, but probably less during the first few. I do think the last 10 rounds of Hornady factory loads were cleaner and based on them grouping about 2-3 inches higher at 200 yards, leads me to believe they were running hotter/faster. I tuned the gas block initially to lock back, but I found that my case necks were getting dinged and they were ejecting at about 4:30-5:00. I opened it up another half turn, mouths are fine and it's ejecting around 3:30-4:00. These cases are probily a little cleaner that when they were just after ejection due to handling, transportation, etc. Even the Range Master commented on how dirty they were.

[dag52]

What is the Horde consensus on Barrel Bedding? Yes, No, maybe? I've read plenty of opinions either way on different forums. I figured I would leave it un-bedded, knowing I could always do it later and have some comparative data. LRRPF52's question leaves me with the impression that maybe I should have.

Thanks again for the help, I am learning something new everyday.

[dag52]

Welcome aboard. I'll have to break this down, since we are dealing with no less than 8 different variables.

Shooting experience/background?
Is the upper receiver face squared?
Is the barrel bedded into the upper?
Is the scope leveled?
What scope mount are you using?
Are the scope mount bolts and ring fastener screws balanced in torque value?

Did you dry-fire until you were comfortable with the reticle not jumping off the diamond?

LRRPF52,

I just got my new hand guard today and will need to remove the barrel nut to install it. So, while I'm at it, do you recommend I square the receiver and bed the barrel extension? If bedding the barrel, is Loctite the way to go or is there something better?

Thanks,
Dave

[Klem]

Thanks for posting the photo.

If the carbon coating is not related to the amount of fill then that debunks my earlier theory.

That's a nice clear line of carbon so looks like a seal line to me. Maybe they are all expanding as they should, but then being dragging out while still sealed. Whatever's coating the inside of that chamber gets dragged out with them. This would happen if they are being extracted before the round exits and the brass deflates. Too much dwell time for the time/pressure curve of that powder maybe. If this is the cause then you need to delay that bolt carrier. A heavier buffer is the normal fix, and/or full-mass carrier.

The only other theory I have is there is something wrong with the annealing and they are NOT expanding and sealing properly. The clean lower half is where the case makes contact with the chamber in battery, and the top half gets coated in crud on firing.

[dag52]

Thanks Klem, I'll try a heavier buffer. I'm using a full mass BC now.

[jurassic]

If the barrel fits snugly in the upper I would not glue it in and a Vltor upper should not need squaring. Any barrel that slides right in or has some wiggle gets a new upper, or green loctite when I build. I do remember reading Bill Alexander saying that all the rifles they build are bedded to the receivers so it may be a good idea I would rather find an upper that fit the barrel better. Mega forged uppers have fit the best and I've had a bunch of different makes.

I also experimented with a different spring and H2 buffer in my rifle when setting up, it made a huge difference, the brass comes out perfectly clean. I have a NM carrier which is essentially an M16 carrier. My rifle works better set up as a carbine then it did with a rifle stock setup.

[VASCAR2]

I normally see people bed the barrel into the reciever with red or blue Loctite as Green makes it much more difficult to remove your barrel at a later date. I also bedded my adjustable gas block before tightening down. I'm using the same Shilen barrel as you but mine is mounted into a PSA blem upper which was square. I agree the Hornady ammo is hotter than my reloads and my brass using CFE 223 look like yours after firing. I'm using an M-16 carrier with a 6 position PSA adjustable stock with standard carbine buffer and spring. I tried a T-2 buffer but my rifle functions better with the carbine buffer.

I can not seat my bullets that long with my Shilen, just curious if your bullets are being jammed into the lands? With my two 6.5 Grendel barels I get more consistent groups loading shorter than longer. I use a Lock N Load chamber tool to measure each particular brand of bullet and at what length the ogive hits the lands. I usually try for 3-5 thousandths off the lands as with some match bullets there is a slight variation in the nose from bullet to bullet.

[LRRPF52]

LRRPF52,

I just got my new hand guard today and will need to remove the barrel nut to install it. So, while I'm at it, do you recommend I square the receiver and bed the barrel extension? If bedding the barrel, is Loctite the way to go or is there something better?

Thanks,
Dave

Especially for 20" barrels and longer, I would bed it. I personally bed any barrel/upper where accuracy is important, which is basically all of my guns. The other way to ensure a super tight fit is a thermo-fit process, where you get an undersized extension tunnel, and over-sized barrel extension OD. Freeze the pipe, and bake the upper, then mate them. Precision rifle builders have been doing that longer than most of us have been riding this planet, Steyr coming to mind as just one example with the SSG-69.

I prefer Blue Loc-tite, since it is easier to pull the barrel when that time comes, but I've heard of several different adhesive or filling compound methods ranging from Red Loc-tite to JB weld to Acra Glass. When I had my .260 Rem built, I told GA Precision that I didn't care if the barrel ever came out of the upper, make that thing one unit, and didn't ask what they used.

There have been people that complain about their .25 MOA-shooting Les Baer 6.5 Grendel's, because they want to install a different handguard, but couldn't get the nut off.

Check your receiver face for square with the Brownell's tool or a lathe, Blue loc-tite it, and move on to how you will set up the gas block for a secure fit. I use Red Loc tite for the gas block mating to the journal. These aren't the only ways to do this, just some common approaches.

Knight's has probably the best solution for sealing up the gas block and gas tube with the Mod 2 system, with no adhesives necessary at all at the block.