Carbon/soot on Case Shoulders

[spudgun]

Glowing red neck is far too hot. You were not testing what you were trying to test with those pieces.

Yes, if you dim the lights in the shop you will be able to see the brass get to a dull glow easier.

 

[AckleymanII]

Last Year, ran not this soot on the shoulder issue in a 6.5x47 lapua using AA4350 with 147 Hornady's.

The soot was increasing in the chamber to where the bolt was getting hard to close. After some research, the lot# of powder I was using was in a recall from Accurate Arms. I changed to H4350 and AA2700 and my issue disappeared.

Dies can be a mis-match from Chamber reamers, also. Large dimension at the shoulder in the barrel, much smaller full length sized Shoulder dimension. The mis-match in chamber/die dimensions , with slow burning powders can cause problems.

There is the simply solution of just barely bumping shoulders back enough, perhaps as little as .001-.0005 that will seal the chamber quicker.

 

[lawrence97]

Are you still running through this process or was a solution found?

Shooting a Proof pre-fit 6.5, Staball 44.1, 140g pills, Lapua LRP, Fed210....hilarious reading your first post it's literally me. Fire forming has been the only time my shoulders weren't messy(no FL resizing done on virgin brass). After 1st full length poof there ya go. Most accurate rifle I've ever owned and at ELR doesn't make a hill of beans. Checked velo and SD/ES at 2500 rounds and same as after barrel sped up at around 200 rounds.

At this point I just look at it as an annoyance, but would be fun to eventually find out the culprit. Have my next Proof back up ready to go on any day when this one says no mas. So interested to see if it's possibly something just with this barrel and my replacement takes care or it. Either way not inclined to burn too many brain cells or time over it given how well it shoots.

Thanks for your input.

Annealing the No turn brass significantly longer seemed to help. I just stopped caring since I was doing everything right and everything on target and chrono looked good. This issue is also dependent on the amount of clearance your chamber has. My no turn bra is .274. Maybe a .273 or .272 would solve the issue but the risk is there if it’s too tight and then you are forced to neck turn. More clearance does not seem detrimental to accuracy but too little will hurt you. There’s also a difference between the thickness of Lapua vs Alpha.

Eventually I just rechambered my 6bra into a 6x47 since the 6bra was falling short at 1000 yards with 20 shot strings and the environment. I am using a No turn 6x47 with Lapua brass and I don’t have any soot/carbon issues. I am very surprised with the performance of this cartridge and how easy it was to get up and running. The good thing is I can use the 2-3 powders I use for my 7mm in the 6x47 such as h4831sc, h4350, rl23 and rl16. The downside is that it uses about 40 grains of powder vs 30gns for the br and the bra.

For your 6.5 I’d suggest longer dwell time under the flame if you are annealing to soften the necks.

 

[Dave M.]

Yes, if you dim the lights in the shop you will be able to see the brass get to a dull glow easier.

I agree 100%. I just annealed today with all the lights off to develop an induction program for some 6BRDX brass. This is by far the single most consistent manner to identify the proper induction annealing temp for brass. This method is very difficult when using flame, that’s why it is so easy to overheat brass using torch annealing.
Dave

 

[DocCarbon]

That previously posted annealing video WAS WRONG !. I caution anyone watching this video to remember We are not privileged to know the Power of the induction coil and it would be 240V European .
However the COLOR of the case and Ductility test are Valid indicators ,that this man Knows what he's doing .

 

[dskogman]

How long are the throats? I get the problem if the bullet isn't seated very deep in the case.

 

[chootem]

Annealing the No turn brass significantly longer seemed to help. I just stopped caring since I was doing everything right and everything on target and chrono looked good. This issue is also dependent on the amount of clearance your chamber has. My no turn bra is .274. Maybe a .273 or .272 would solve the issue but the risk is there if it’s too tight and then you are forced to neck turn. More clearance does not seem detrimental to accuracy but too little will hurt you. There’s also a difference between the thickness of Lapua vs Alpha.

Eventually I just rechambered my 6bra into a 6x47 since the 6bra was falling short at 1000 yards with 20 shot strings and the environment. I am using a No turn 6x47 with Lapua brass and I don’t have any soot/carbon issues. I am very surprised with the performance of this cartridge and how easy it was to get up and running. The good thing is I can use the 2-3 powders I use for my 7mm in the 6x47 such as h4831sc, h4350, rl23 and rl16. The downside is that it uses about 40 grains of powder vs 30gns for the br and the bra.

For your 6.5 I’d suggest longer dwell time under the flame if you are annealing to soften the necks.

Thanks appreciate it. Similar it's quite frankly just an annoyance and you will laugh at my reason for still looking to tackle it. Performance is outstanding, but when they get that dirty I have to clean my brass/barrel b/c I'm only bumping back .001(which hasn't helped with soot) and it can get hard to close after 100 or so. Back when I didn't have this barrel/issue I'd go several hundred b/t brass tumbling and barrel cleaning. Yes I know a total slouch. Going to see if possibly it's just how my pre-fit chamber was on this barrel when I swap it out for the new one(same Proof) sometime soon. Maybe my die matches up with it a bit better.

 

[JMayo]

When My bra got 1k rounds on it, it started getting the ring on the sholder, when it used to stop at the neck junction. I changed barrels at 1400 rounds so i didn't get continue trying to fix it.
But Hardening of the brass and too much sholder bump is what i came up with.
Try Bumping it back only .001 and anneal it.

Brass may be too long keeping sholder from mating to chamber. A bore scope from the muzzel end while case is chambered, imo

 

[Scooby-93]

Just bumping this thread as I have the same issue with 22 creedmoor

 

[6.5 forever]

Just bumping this thread as I have the same issue with 22 creedmoor

Maybe you will be able to kickstart this two year old thread.

 

[Scooby-93]

Also having the issue now with a 22-250.

Happening only with FL sized brass - stripped bolt method so bolt only just drops so .001-.002 shoulder bump.

I am thinking I’m not removing all of the case lube sufficiently?

Hornady one shot and using brake cleaner on tissue paper to remove.

I use the exact same sizing / lube / cleaning method on another 2 calibres and have no issues.

Anyone have any other ideas or experiences with this?

 

[6.5 forever]

Also having the issue now with a 22-250.

Happening only with FL sized brass - stripped bolt method so bolt only just drops so .001-.002 shoulder bump.

I am thinking I’m not removing all of the case lube sufficiently?

Hornady one shot and using brake cleaner on tissue paper to remove.

I use the exact same sizing / lube / cleaning method on another 2 calibres and have no issues.

Anyone have any other ideas or experiences with this?

I would think the difference is probably the type of powder and burn characteristics. Not anything to do with your process.

 

[Scooby-93]

I would think the difference is probably the type of powder and burn characteristics. Not anything to do with your process.

It’s happened with different powders in the same cartridges.

I’m actually thinking it may be the hornady one shot? I wipe it off the outside of the case with brake cleaner after sizing but I don’t remove or brush inside the necks

 

[Scooby-93]

Picture of 2 times fired, first time since FL sized using oneshot.

On 22creedmoor the carbon soot is at least double what’s in this picture, almost half the shoulder

 

[Scooby-93]

22 creedmoor