Fouling patterns on brass

sir_n0thing · March 19, 2011, 07:44 PM

I'm really glad places like this forum exist, my Google-fu is failing me on some of these questions...

I fired a couple rounds of handloads today and noticed that the pattern of the fouling on the case neck is different than what I am used to seeing with factory ammo. I stopped at that point and went back to factory ammo for the remainder of my day at the range.
In general, with most standard ~$18/box ammo such as Core-Lokt and Winchester silver box, I get a wavy pattern around the neck. With premium ammo such as Federal's "good stuff" I get NO pattern on the neck.
With my handloads, I got a solid straight ring around the base of the neck.
The first attached image shows the wavy pattern I'm used to seeing, and the second shows the straight ring from my handloads. It almost makes me wonder if the neck wasn't sealing properly when fired?
Please forgive my lack of knowledge on this stuff. Reloading is brand new to me and I'm trying to be very careful about it.
In case it matters, my handloads were...
New Remington brass, full length sized in a Lee press/Lee dies
CCI 200 LR primers
52gr H4350 (starting low and working up)
110gr Sierra Pro Hunter bullets

I also noticed three of them were a bit harder than normal to chamber (I chambered all five rounds that I had brought to test). It appears the cases are within spec as far as length and neck dimensions, but I had to push harder on the bolt to chamber them. Yeah, I'm being paranoid about every little thing.

jimbob86 · March 19, 2011, 07:51 PM

Quote:

I also noticed three of them were a bit harder than normal to chamber (I chambered all five rounds that I had brought to test). It appears the cases are within spec as far as length and neck dimensions, but I had to push harder on the bolt to chamber them. Yeah, I'm being paranoid about every little thing

I suspect you set the shoulder back to far when sizing your cases, allowing no headspace. Follow the die adjustment directions exactlyto make a dummy round and see if it does not chamber without difficulty.

amamnn · March 21, 2011, 03:06 PM

I did not see in the original post a great many details which would affect an answer but---Assuming we are talking about FL sizing the same brass that had been bought as factory loaded and shot one time then reloaded, resulting in the problem and post here:

If he had set the shoulder back further then it would have more, not less headspace. Or more correctly the case would be incorrectly formed to chamber easily in the headspace provided in the rifle's chamber, if the shoulder was not set back sufficiently. Hard chambering rounds might be caused from not setting the shoulder back enough in the case of a tight chamber or by a lot of neck tension or by over crimping the bullet/casemouth if crimping was done. Also hard chambering can be encountered if the case body has been allowed to expand without outside limits (the chamber walls) and is not resized completely. This is why semi auto rifles require ammo that has been FL sized. Still, going back and reviewing the die seating is a good idea as is comparing all measurements of a handloaded round to the factory round which chambered easily.

As to the original Q one should not expect to be able to exactly reproduce "fouling" patterns on the brass when handloading since you will not be reproducing the exact cartridge components. You should be able to tailor your cartridges to your rifle producing a more accurate round and the hell with the soot on the case................as an example, the well respected for accuracy AR direct gas impingement setup is going to make really sooty cases depending upon the powder used an the pressures to which it is loaded. The little bit of soot on the casemouth in the pix is not really indicative of an under pressure round. If you get one of those you'll know it, believe me.

hk33ka1 · March 21, 2011, 03:31 PM

They look fine to me. Are they accurate? I think you're doin everything ok.

Sometimes lower pressure loads allow more gas to leak back if the case isn't expanding to fill the chamber, just as primers can back out and no be reseated by some low pressure loads.

Doodlebugger45 · March 21, 2011, 05:00 PM

Ehhh... I dunno exactly what makes some loads look like they do on the neck. I see differences in my .243 brass that I got from firing factory ammo. Some of them hardly have any fouling at all. But the most accurate factory load in my rifle is some Hornady stuff and it leaves some black fouling on the neck close to the shoulder junction that is nearly impossible to get off even after soaking in mineral spirits or carb cleaner. No big deal though. It fires accurately, doesn't harm the brass and it loads up again just fine. For he most part though, my own loads seem to have less fouling on the necks than factory ammo. I don't really notice a correlation between the fouling and the pressure of the load.

mehavey · March 21, 2011, 06:42 PM

Quote:

"...first shows the wavy pattern I'm used to seeing [on commercial loads], and the second shows the straight ring from my handloads. ...I also noticed three of [my handloads] were a bit harder than normal to chamber...."

Drumroll, please.....

The commercial loads are all SAAMI-minimal sized at the factory and the gas leaks back along the neck while the case is streching foward to seal the chamber. The wavy pattern likely reflects variations in neck thickness/runout/expansion while this is happening and the case shoulder/neck is simultaneouly seating/deforming itself to best fit.

Your handload's resized headspace is [very, very] slightly too long for the chamber [hence the bolt resistance to closing]. The case shoulder/neck is thereby [mostly] force-sealed at the chamber/shoulder interface ...and you get a clean gas impingement line around the case at that seal point.

FrankenMauser · March 21, 2011, 11:03 PM

What's the actual measurement on neck wall thickness?
They look a little thick, to me. (And could cause resistance while chambering.)

It does look as though you're not fully sizing those cases, though. (This assumption is based on the difficult chambering and photo #2.)

As for the Federal factory stuff sealing better ...
Federal runs faster powders than most manufacturers, and does so in softer cases. It makes for a quick-sealing load, that almost never shows soot marks.

It's not at all uncommon for bottleneck rifle cases to show soot around the neck, even with hot loads.

sir_n0thing · March 22, 2011, 01:13 PM

Thanks for all the replies. I will look into the suggested points!
To answer one question, my handloads were in new Remington brass. I used a Lee full length die, set per the instructions that came with them ...

Set die to just touch the ram when it is fully up, then lower ram, turn die in 1/3 - 1/4 turn more, raise ram and tighten the nut.

Accuracy with the hand loads was ok, not great.

I suspect as someone mentioned that the low starting charge caused less of a seal and allowed the fouling farther down the neck.

Sent from my GSBv1.8.1 ERIS using Tapatalk

snuffy · March 22, 2011, 02:20 PM

I never even look at the outside of case necks. It makes little or no difference to the performance of the load.

Sir-N you're grasping at straws. Or nit picking. Call it what you want, pay no more attention to it.

NESHOOTER · March 22, 2011, 04:58 PM

I suspect something is not set properly each completed round should chamber go into battery without (being harder) do you mean by that excessive force to put the bolt handle down in its locked firing position? Chamber one of your handloads (DO NOT SHOOT IT) remove it and inspect it do you see marks on the bullet end? Did you perform a COL with a gauge to the specific bullet you are shooting in the rifle? If you remove and you COL on the case is ok and set to spec's then what does you bullet end say if it has marks then it maybe seated too far OUT... and if you don't have a COL gauge then blacken the bullet end each time to measure until the bullet is off the lands/rifling of the barrel.

sir_n0thing · March 22, 2011, 05:57 PM

@snuffy: Call it "new to reloading paranoia because I want to maintain a full count of digits on my fingers"

@NESHOOTER: I'll check that again, but I'm 90% certain that my COL is good, and maybe a couple thousandths under. I'll double check that though.

snuffy · March 22, 2011, 06:08 PM

Quote:

@snuffy: Call it "new to reloading paranoia because I want to maintain a full count of digits on my fingers"

Sir-N, nothing wrong with that! I suspected you were unsure if it made a difference.

sir_n0thing · March 22, 2011, 10:27 PM

Quote:

Sir-N, nothing wrong with that! I suspected you were unsure if it made a difference.

I'm over-analyzing every little thing right now.... triple checking powder charges, zeroing the scale every other charge...

Heck, I'm weighing every bullet just to see how many 10ths of a grain they vary from one to the next!

m&p45acp10+1 · March 22, 2011, 10:42 PM

I may have missed it somewhere if you posted it, or someone else did.

Are you checking the length of your brass to see if it is in spec and trimming if necessary?

Also try seating without crimping, or backing off of the crimp just a tad, also you may try seating the bullet just a slight tad deeper in a dummy round to see if it helps with the closing of the bolt.

I keep one dummy round for every bullet style I reload for to help with adjusting the seating die when changing bullet types. I bag each one in a coin envelope with the bullet Mfg, weight, and type, as well as COL written on the envelope.

oneoldsap · March 23, 2011, 02:25 PM

That little smudge is caused by the Chamfer on the outside of the case mouth applied when prepping cases . A little bit of gas sneaks out before the case seals to the chamber . That's my story and I'm sticking to it ! Regular Chamber cleaning keeps it from being any kind of issue .

89blazin · March 23, 2011, 04:14 PM

It almost makes me wonder if the neck wasn't sealing properly when fired

The neck does not seal, the chambered body does.

March 21, 2011, 03:06 PM	#3
amamnn Senior Member Join Date: May 13, 2006 Location: WA, the left armpit of the USA Posts: 1,323	I did not see in the original post a great many details which would affect an answer but---Assuming we are talking about FL sizing the same brass that had been bought as factory loaded and shot one time then reloaded, resulting in the problem and post here: If he had set the shoulder back further then it would have more, not less headspace. Or more correctly the case would be incorrectly formed to chamber easily in the headspace provided in the rifle's chamber, if the shoulder was not set back sufficiently. Hard chambering rounds might be caused from not setting the shoulder back enough in the case of a tight chamber or by a lot of neck tension or by over crimping the bullet/casemouth if crimping was done. Also hard chambering can be encountered if the case body has been allowed to expand without outside limits (the chamber walls) and is not resized completely. This is why semi auto rifles require ammo that has been FL sized. Still, going back and reviewing the die seating is a good idea as is comparing all measurements of a handloaded round to the factory round which chambered easily. As to the original Q one should not expect to be able to exactly reproduce "fouling" patterns on the brass when handloading since you will not be reproducing the exact cartridge components. You should be able to tailor your cartridges to your rifle producing a more accurate round and the hell with the soot on the case................as an example, the well respected for accuracy AR direct gas impingement setup is going to make really sooty cases depending upon the powder used an the pressures to which it is loaded. The little bit of soot on the casemouth in the pix is not really indicative of an under pressure round. If you get one of those you'll know it, believe me. __________________ "If the enemy is in range, so are you." - Infantry Journal Last edited by amamnn; March 21, 2011 at 03:28 PM.

March 21, 2011, 11:03 PM	#7
FrankenMauser Senior Member Join Date: August 25, 2008 Location: In the valley above the plain Posts: 13,424	What's the actual measurement on neck wall thickness? They look a little thick, to me. (And could cause resistance while chambering.) It does look as though you're not fully sizing those cases, though. (This assumption is based on the difficult chambering and photo #2.) As for the Federal factory stuff sealing better ... Federal runs faster powders than most manufacturers, and does so in softer cases. It makes for a quick-sealing load, that almost never shows soot marks. It's not at all uncommon for bottleneck rifle cases to show soot around the neck, even with hot loads. __________________ Don't even try it. It's even worse than the internet would lead you to believe.

March 22, 2011, 01:13 PM	#8
sir_n0thing Senior Member Join Date: February 27, 2011 Location: WI, USA Posts: 281	Thanks for all the replies. I will look into the suggested points! To answer one question, my handloads were in new Remington brass. I used a Lee full length die, set per the instructions that came with them ... Set die to just touch the ram when it is fully up, then lower ram, turn die in 1/3 - 1/4 turn more, raise ram and tighten the nut. Accuracy with the hand loads was ok, not great. I suspect as someone mentioned that the low starting charge caused less of a seal and allowed the fouling farther down the neck. Sent from my GSBv1.8.1 ERIS using Tapatalk __________________ You can take the Texan out of Texas, but you can't take Texas out of the Texan.

March 22, 2011, 02:20 PM	#9
snuffy Senior Member Join Date: May 20, 2001 Location: Oshkosh wi. Posts: 3,055	I never even look at the outside of case necks. It makes little or no difference to the performance of the load. Sir-N you're grasping at straws. Or nit picking. Call it what you want, pay no more attention to it. __________________ The more people I meet, the more I love my dog They're going to get their butts kicked over there this election. How come people can't spell and use words correctly?

March 22, 2011, 05:57 PM	#11
sir_n0thing Senior Member Join Date: February 27, 2011 Location: WI, USA Posts: 281	@snuffy: Call it "new to reloading paranoia because I want to maintain a full count of digits on my fingers" @NESHOOTER: I'll check that again, but I'm 90% certain that my COL is good, and maybe a couple thousandths under. I'll double check that though. __________________ You can take the Texan out of Texas, but you can't take Texas out of the Texan.

March 21, 2011, 03:31 PM	#4
hk33ka1 Senior Member Join Date: April 20, 2010 Posts: 275	They look fine to me. Are they accurate? I think you're doin everything ok. Sometimes lower pressure loads allow more gas to leak back if the case isn't expanding to fill the chamber, just as primers can back out and no be reseated by some low pressure loads.

March 21, 2011, 05:00 PM	#5
Doodlebugger45 Senior Member Join Date: April 15, 2009 Location: Wyoming Posts: 1,717	Ehhh... I dunno exactly what makes some loads look like they do on the neck. I see differences in my .243 brass that I got from firing factory ammo. Some of them hardly have any fouling at all. But the most accurate factory load in my rifle is some Hornady stuff and it leaves some black fouling on the neck close to the shoulder junction that is nearly impossible to get off even after soaking in mineral spirits or carb cleaner. No big deal though. It fires accurately, doesn't harm the brass and it loads up again just fine. For he most part though, my own loads seem to have less fouling on the necks than factory ammo. I don't really notice a correlation between the fouling and the pressure of the load.

March 22, 2011, 04:58 PM	#10
NESHOOTER Senior Member Join Date: October 16, 2009 Posts: 517	I suspect something is not set properly each completed round should chamber go into battery without (being harder) do you mean by that excessive force to put the bolt handle down in its locked firing position? Chamber one of your handloads (DO NOT SHOOT IT) remove it and inspect it do you see marks on the bullet end? Did you perform a COL with a gauge to the specific bullet you are shooting in the rifle? If you remove and you COL on the case is ok and set to spec's then what does you bullet end say if it has marks then it maybe seated too far OUT... and if you don't have a COL gauge then blacken the bullet end each time to measure until the bullet is off the lands/rifling of the barrel.

March 22, 2011, 10:42 PM	#14
m&p45acp10+1 Senior Member Join Date: May 3, 2009 Location: Central Texas Posts: 3,930	I may have missed it somewhere if you posted it, or someone else did. Are you checking the length of your brass to see if it is in spec and trimming if necessary? Also try seating without crimping, or backing off of the crimp just a tad, also you may try seating the bullet just a slight tad deeper in a dummy round to see if it helps with the closing of the bolt. I keep one dummy round for every bullet style I reload for to help with adjusting the seating die when changing bullet types. I bag each one in a coin envelope with the bullet Mfg, weight, and type, as well as COL written on the envelope. __________________ No matter how many times you do it and nothing happens it only takes something going wrong one time to kill you.

March 23, 2011, 02:25 PM	#15
oneoldsap Senior Member Join Date: September 16, 2009 Location: I live in the foot of the Green Mountains of Vermont Posts: 1,602	That little smudge is caused by the Chamfer on the outside of the case mouth applied when prepping cases . A little bit of gas sneaks out before the case seals to the chamber . That's my story and I'm sticking to it ! Regular Chamber cleaning keeps it from being any kind of issue .

March 23, 2011, 04:14 PM	#16
89blazin Senior Member Join Date: March 13, 2009 Posts: 107	It almost makes me wonder if the neck wasn't sealing properly when fired The neck does not seal, the chambered body does.