carbon

sako2 · June 5, 2021, 01:54 PM

I'm getting a lot of carbon on the outside of the case neck with hornady brass. The same load with adg brass doesn't do it. I weighed the case's both hold the same amount of h2o. Seems like i'm not getting the same pressure.

**Unclenick** · June 5, 2021, 03:09 PM

One possibility is that the ADG may be annealed a little softer at the neck at the factory than Hornady is. Another is that your Hornady brass has been subjected to more reloading cycles. The Hornady alloy probably isn't identical. Either can make the Hornady necks require greater pressure to fully expand to fill the chamber. Another possibility is the Hornady neck walls are thicker, though that seems unlikely.

Did you compare the water capacity as-fired? That's the form that affects peak pressure.

Shadow9mm · June 5, 2021, 03:29 PM

How many time have they been fired? Have either been annealed?

hounddawg · June 5, 2021, 04:26 PM

take a measurement of the neck OD of both cases with a round loaded. Are they the same? Tiny Boyle goes into carbon rings and analyzing them in his book. It could be caused by a number of things but the bottom line is are you happy with how they both shoot? I get carbon bad on my 6BR but I load for accuracy not speed and my loads tend to be on the light side

sako2 · June 5, 2021, 05:29 PM

The adg brass has more firing on it. The adg cases have about 15 firings on them. The hornady has about 12 firings on them. They have all been annealed after each firing. They shoot good. I'm happy with them. Never thought i would get that many firings on them. Haven't lost a hornady case yet.

zeke · June 5, 2021, 08:01 PM

When not shooting great volume, am using damp rag to wipe off any carbon on case neck immediately/soon after brass is ejected. But do not shoot any sort of timed competition, and sometimes tough to gather the brass from semi.

sako2 · June 5, 2021, 08:27 PM

It comes off when i wet tumble them. Isn't it a sign of under pressure?

zeke · June 6, 2021, 05:14 AM

It can be, but more details would help. Some calibers have greater brass variations than others. It might also matter at what level (near min/near max) the powder charge is.

If you are using mid to high level powder charge and everything else being the same except brass, would agree with others that the brass thickness in the neck may be less. Some chambers will have get carbon on the necks simply because the chamber neck is not real tight, or you fired enough rounds to get it dirty.

sako2 · June 6, 2021, 06:20 AM

It's a 6.5 prc. With a max charge of magpro.

zeke · June 6, 2021, 10:04 AM

With max charges am gonna guess the loads using Hdy brass are not "under pressure" . Are they slightly enough less pressure to not seal the case necks against the case walls to keep carbon from getting on the neck? Would have no idea, but again guessing the carbon is just due to metallurgic/dimensional differences.

Did you chrono the average velocity's of the loads using differing brass?

scatterbrain · June 6, 2021, 10:54 AM

Your well used brass may not have a uniform neck thickness on all the surface of the neck. The seal to the barrel neck will not be uniform a allow soot to escape.

sako2 · June 6, 2021, 02:40 PM

Yes i chronoed the 2 loads average is 2980. I have 1500 rounds down the tube. I'm going to give it a cleaning and go from there.

June 5, 2021, 01:54 PM	#1
sako2 Senior Member Join Date: April 12, 2009 Posts: 738	carbon I'm getting a lot of carbon on the outside of the case neck with hornady brass. The same load with adg brass doesn't do it. I weighed the case's both hold the same amount of h2o. Seems like i'm not getting the same pressure.

June 5, 2021, 03:09 PM	#2
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,060	One possibility is that the ADG may be annealed a little softer at the neck at the factory than Hornady is. Another is that your Hornady brass has been subjected to more reloading cycles. The Hornady alloy probably isn't identical. Either can make the Hornady necks require greater pressure to fully expand to fill the chamber. Another possibility is the Hornady neck walls are thicker, though that seems unlikely. Did you compare the water capacity as-fired? That's the form that affects peak pressure. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

June 5, 2021, 03:29 PM	#3
Shadow9mm Senior Member Join Date: March 21, 2012 Location: Indianapolis, IN Posts: 3,967	How many time have they been fired? Have either been annealed? __________________ I don't believe in "range fodder" that is why I reload.

June 5, 2021, 04:26 PM	#4
hounddawg Senior Member Join Date: March 1, 2009 Posts: 4,232	take a measurement of the neck OD of both cases with a round loaded. Are they the same? Tiny Boyle goes into carbon rings and analyzing them in his book. It could be caused by a number of things but the bottom line is are you happy with how they both shoot? I get carbon bad on my 6BR but I load for accuracy not speed and my loads tend to be on the light side __________________ “How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek

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June 5, 2021, 05:29 PM	#5
sako2 Senior Member Join Date: April 12, 2009 Posts: 738	The adg brass has more firing on it. The adg cases have about 15 firings on them. The hornady has about 12 firings on them. They have all been annealed after each firing. They shoot good. I'm happy with them. Never thought i would get that many firings on them. Haven't lost a hornady case yet.

June 5, 2021, 08:01 PM	#6
zeke Senior Member Join Date: November 17, 1999 Location: NW Wi Posts: 1,671	When not shooting great volume, am using damp rag to wipe off any carbon on case neck immediately/soon after brass is ejected. But do not shoot any sort of timed competition, and sometimes tough to gather the brass from semi.

June 5, 2021, 08:27 PM	#7
sako2 Senior Member Join Date: April 12, 2009 Posts: 738	It comes off when i wet tumble them. Isn't it a sign of under pressure?

June 6, 2021, 05:14 AM	#8
zeke Senior Member Join Date: November 17, 1999 Location: NW Wi Posts: 1,671	It can be, but more details would help. Some calibers have greater brass variations than others. It might also matter at what level (near min/near max) the powder charge is. If you are using mid to high level powder charge and everything else being the same except brass, would agree with others that the brass thickness in the neck may be less. Some chambers will have get carbon on the necks simply because the chamber neck is not real tight, or you fired enough rounds to get it dirty.

June 6, 2021, 06:20 AM	#9
sako2 Senior Member Join Date: April 12, 2009 Posts: 738	It's a 6.5 prc. With a max charge of magpro.

June 6, 2021, 10:04 AM	#10
zeke Senior Member Join Date: November 17, 1999 Location: NW Wi Posts: 1,671	With max charges am gonna guess the loads using Hdy brass are not "under pressure" . Are they slightly enough less pressure to not seal the case necks against the case walls to keep carbon from getting on the neck? Would have no idea, but again guessing the carbon is just due to metallurgic/dimensional differences. Did you chrono the average velocity's of the loads using differing brass?

June 6, 2021, 10:54 AM	#11
scatterbrain Senior Member Join Date: February 7, 2015 Posts: 160	Your well used brass may not have a uniform neck thickness on all the surface of the neck. The seal to the barrel neck will not be uniform a allow soot to escape.

June 6, 2021, 02:40 PM	#12
sako2 Senior Member Join Date: April 12, 2009 Posts: 738	Yes i chronoed the 2 loads average is 2980. I have 1500 rounds down the tube. I'm going to give it a cleaning and go from there.