Black sealant in military LC-69 case necks

GWV · January 20, 2012, 03:38 PM

I purchased 500 new LC-69 cases, over 15 years ago.
I went to reload some and found a black sealant in side the case necks.
I want to fl resize these before loading, and am afraid in doing so, will crud up my resizing die.
How can I remove this sealant ?

3kgt2nv · January 20, 2012, 03:41 PM

try a 22cal copper bore brush or tumble them to remove it.

**Unclenick** · January 20, 2012, 04:00 PM

That sealant is asphaltum, or pitch, so your cases were pull-downs from loaded ammo. Nothing wrong with that. The sealant dissolves completely and pretty quickly in odorless mineral spirits and probably any of a dozen other solvents. A Q-tip wet with mineral spirits will get it out with some rubbing, but it's easier just to stand the cases mouth-down in a covered dish with half an inch of mineral spirits in it and let them sit overnight. Pull them out and let them dry the next day.

medalguy · January 21, 2012, 02:15 AM

Unclenick is right. There's maybe another way also. Several years ago I bought several thousand pulldown .30 M2 bullets with the sealer on them. I just put them in the tumbler and added a fair amount of mineral spirits to the cob, and tumbled them clean in 2-3 hours. I'm not sure if this would work with brass or not, but it might be worth a try. It's easier than having to brush every neck.

**Unclenick** · January 21, 2012, 06:44 PM

I think that should be OK. You don't want corncob to swell inside cases, or it will get stuck, but mineral spirits won't swell it as much as water does. Try just a small capful at a time, checking every hour. I know a lot of folks add that small amount to tumble just to wake the polish up a little.

hagar · January 21, 2012, 09:46 PM

I think it more than a sealant, it also prevents the case bonding with the bullet, a problem I have run into with reloads I loaded a longgg time ago.

sob (sweet ole bill) · January 22, 2012, 04:38 AM

Try brake cleaning fluid. Used it on pulled .308's worked fast and easy

SOB

**Unclenick** · January 23, 2012, 04:52 PM

Hagar,

It doesn't usually cover the whole bullet. They just painted a stripe or two inside each neck to act sort of like O-rings. Bullets still get stuck hard if the ammo gets old enough. Normal pull weight is well under 100 lbs, but a former Aberdeen Proving Grounds employee said he'd measured up to 600 lbs pull in some old stock. Still fired properly, though.

FM12 · January 24, 2012, 12:25 PM

If these have not been fired, I doubt they need sizing at all. YMMV.

GerryG · January 26, 2012, 07:43 AM

At the minimum, neck sizing may be needed for proper bullet tension.

January 20, 2012, 03:38 PM	#1
GWV Junior Member Join Date: October 7, 2009 Location: Ruffs Dale , PA. Posts: 11	Black sealant in military LC-69 case necks I purchased 500 new LC-69 cases, over 15 years ago. I went to reload some and found a black sealant in side the case necks. I want to fl resize these before loading, and am afraid in doing so, will crud up my resizing die. How can I remove this sealant ?

January 20, 2012, 04:00 PM	#3
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,060	That sealant is asphaltum, or pitch, so your cases were pull-downs from loaded ammo. Nothing wrong with that. The sealant dissolves completely and pretty quickly in odorless mineral spirits and probably any of a dozen other solvents. A Q-tip wet with mineral spirits will get it out with some rubbing, but it's easier just to stand the cases mouth-down in a covered dish with half an inch of mineral spirits in it and let them sit overnight. Pull them out and let them dry the next day. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

January 21, 2012, 06:44 PM	#5
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,060	I think that should be OK. You don't want corncob to swell inside cases, or it will get stuck, but mineral spirits won't swell it as much as water does. Try just a small capful at a time, checking every hour. I know a lot of folks add that small amount to tumble just to wake the polish up a little. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

January 21, 2012, 09:46 PM	#6
hagar Senior Member Join Date: February 20, 2000 Location: Colombia, SC Posts: 745	I think it more than a sealant, it also prevents the case bonding with the bullet, a problem I have run into with reloads I loaded a longgg time ago. __________________ I don't have time for busy people

January 22, 2012, 04:38 AM	#7
sob (sweet ole bill) Member Join Date: October 13, 2008 Location: coastal North Carolina Posts: 65	Back Sealant Try brake cleaning fluid. Used it on pulled .308's worked fast and easy SOB

January 20, 2012, 03:41 PM	#2
3kgt2nv Senior Member Join Date: January 7, 2012 Location: hudson valley NY Posts: 517	try a 22cal copper bore brush or tumble them to remove it.

January 21, 2012, 02:15 AM	#4
medalguy Senior Member Join Date: August 31, 2009 Location: New Mexico Posts: 1,033	Unclenick is right. There's maybe another way also. Several years ago I bought several thousand pulldown .30 M2 bullets with the sealer on them. I just put them in the tumbler and added a fair amount of mineral spirits to the cob, and tumbled them clean in 2-3 hours. I'm not sure if this would work with brass or not, but it might be worth a try. It's easier than having to brush every neck.

January 23, 2012, 04:52 PM	#8
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,060	Hagar, It doesn't usually cover the whole bullet. They just painted a stripe or two inside each neck to act sort of like O-rings. Bullets still get stuck hard if the ammo gets old enough. Normal pull weight is well under 100 lbs, but a former Aberdeen Proving Grounds employee said he'd measured up to 600 lbs pull in some old stock. Still fired properly, though. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

January 24, 2012, 12:25 PM	#9
FM12 Senior Member Join Date: February 5, 2007 Location: Monroeville, Alabama Posts: 1,683	If these have not been fired, I doubt they need sizing at all. YMMV.

January 26, 2012, 07:43 AM	#10
GerryG Member Join Date: March 21, 2007 Location: Michigan Posts: 17	At the minimum, neck sizing may be needed for proper bullet tension.

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