Very bad leading with CMMG conversion

My friend has a conversion and we took it out for some fun. Couldn't hit a damn thing with it thought it was the barrel (1/7), and then blamed the ammmo. Finally took it apart and looked down the barrel to find it full of lead. Tried my extra conversion I had in the rnage bag and it ran fine.

Figured out the chamber adapter was causing the lead to melt and fouling the barrel very bad. I took the adapter off and cleaned/looked at it and it appears very rough. Tried to polish it out but It still looks bad.

My friend was devistated as he thought his gun was crap (1st AR). I assured him if it happens again we will get it fixed. At least I know it will run with my conversion (original ceiner)

Anyone else have these problems?

Never heard of it but CMMG will take care of it. Just give them a call.
With the volume going out right now, there are bound to be some bad parts occasionally.
Dave N

Never use mechanical/abrasive methods to de-lead a heavily lead fouled chamber/
bore/barrel/muzzle device. As careful as you may be, any use of polish or abrasive may
result in further roughing which will cause rapid fouling.
Use the proper chemical soultion and follow the manufacturers'
directions. These may help, but CMMG will definately help.

http://www.midwayusa.com/product/588466/sharp-shoot-r-wipe-out-no-lead-bore-cleaning-solvent-8-oz-liquid

http://www.midwayusa.com/product/134766/montana-x-treme-usa-shooting-team-rimfire-blend-bore-cleaning-solvent-6-oz-liquid

Ted

I've used a .22 conversion kit (have Ceiner and CMMG) in five different AR15's. No issues in 4 of them. The 5th one leaded up badly. Took a couple of weeks, lots of different solvents/cleaners, soaking, patching, brushing, etc. and finally got most of the rough looking stuff out and will only shoot .223 ammo in that AR from now on. It is a chrome lined barrel, too, 1 turn in 9". Don't know what happened but it really mess that barrel up.

Unfortunately, chrome bores are not exempt from defects. What is really at the core of their
fouling is a rough surface that is now, after the chrome plating deposit, nearly impossible to
lap out. That barrel will always foul, be it copper or lead (especially lead due to its soft nature),
the many imperfections which are as hard as, well, chrome, will always abrade the bullet.

When they are done properly, a chrome barrel is nearly impervious to fouling and cleaning one
is a snap, as is true for any quality barrel made with great attention to detail, care, and precision.

In the benchrest game, we will frequently resort to Tubb's final finish, while primarily helpful to the
freebore, leade, and throat of a worn barrel, it has been known to help smooth out rough barrels too:

http://www.midwayusa.com/product/152946/tubb-final-finish-tms-throat-maintenance-system-224-caliber

Ted

What ammo were you using?

uh no. I was not de-leading. I was trying to get the damn thing smooth. You can see the abrasions in the adapter.

Its kinda hard to rough up the chamber using the correct polish. I was not sanding or honing, but polishing

It didn't matter. CCIMMs, and some blazer. The other conversion ran it all fine.

You need to call CMMG. Sounds like the chamber adapter needs to be replaced if it's
improperly machined. Should be no problem at all for them to ship a new one. Sorry
but with the volume of kits they ship your friend got one of the very very few that have
a problem...

Dave S

my friend is in the process. I just wanted to see if this has happened to others.

I personally have 3 original ceiner kits and a keuhl upper, and I have shot with friends that have multiple kits, just never seen something like this

I'm sure CMMG will make it right. I've never had the severity of lead buildup you describe through my kits.

Copyright © 1996 - 2013 :: AR15.Com LLC :: All Rights Reserved.
Any use of this content without express written consent is prohibited.