View Full Version : AR-15 Silver Bear Ammo problem???
May 9, 2010, 03:55 PM
Well it looks like I opened my big mouth on another thread about how I never have any problems shooting cheap Silver Bear ammo too soon. I did never have a problem until the past two times out.
I will explain I have a Smith & Wesson M&P15-T I have put thousands of rounds threw it with no problems. The problem I am having is the bolt will not open and eject the spent case I will have to pull back on the charging handle pretty hard to get it to open and eject the spent case. I thought it was the case actually getting stuck in the chamber, but found out after tinkering with it that its not the case getting stuck some how the bolt is not unlocking and wanting to come back, let me add that I am not having any problems with brass cased ammo, just steel cased Silver Bear. I don't get it I can take live rounds(unspent rounds with bullet) and cycle them no problem, but when I take a spent case and reinsert it in the chamber to check if it will pull back out I have to jimmy the charging handle back and forth a few times to get it to unlock. Keep in mind that the spent case will slide in and out the chamber no problem, for some reason the bolt will not unlock with the steel case ammo. Any ideas why or whats not happening or is happening.
Thanks for any help.:confused:
May 9, 2010, 06:18 PM
Those silver bear cases I believe are zinc coated, you might have some of that building up in your chamber and the casings are sticking to it when fired. Might want to get after the chamber with a brush and lots of solvent, should help. I've been using a few hundred rounds of silver bear and wolf , but I scrub the chamber after less than 100 rounds. I don't shoot a whole lot at once with my AR. Good luck with this Palmetto and let us know how you are doing with this.
May 9, 2010, 08:09 PM
I think thats why Wolf went to the enamel coating on their rifle ammo instead of zink. The Russian weapons had chamber dimentions for it but US weapons did not. The build up from the enamel coating is still a problem from what I have heard...
May 9, 2010, 08:23 PM
I don't think Silver Bear has a Zinc coating, but it is Zinc plated which is not suppose to build up, also if it was some kind of build up in the chamber why would brass ammo not be giving me any problems.........:confused:
Come and take it.
May 9, 2010, 08:34 PM
laquer or polymer coating is the way to go.
I wonder sometimes if a small amount of lubrication on the cases might prevent case stickage. It used to be a practice for some semi-automatic weapons before and during the second world war.
May 9, 2010, 08:59 PM
I've used Silver Bear in a couple ARs. One was way overgassed and ripped part of the rim off the case. Another had no issues.
Some ARs have no issues with steel cased ammo. Some do. I personally wouldn't try it in an unchromed chamber- the extra lubricity will ease case extraction. It could be that your rifle just doesn't like it. I'd either try some lacquered stuff in there or just stick to brass.
May 9, 2010, 09:21 PM
Id just stick to brass ammo. A lot of my buddys have had trouble with their ars when using steel coated ammo.
PMC makes decently priced brass ammo that shoots fine.
May 9, 2010, 09:32 PM
Well like I said I have shot well over 500 rounds of Silver Bear ammo with no problem at all, so something has happened to cause this problem. I am thinking its some kind of build up.....:confused:
May 10, 2010, 08:43 AM
It seems to me that you are suffering from a defect in the gas system somewhere. I'd really double or even triple check the gas system.
May 10, 2010, 12:10 PM
Yea but, I can't even manualy pull the charging handle back at times its like the bolt doesn't want to rotate and unlock to let the bolt carrier groub come back.
May 10, 2010, 03:21 PM
I started having the same issue(s) with my DPMS after thousands of Silver Bear with sporatic FTE. I simply bought the "O" ring or Delta ring and installed it under my extractor. No issues since.:o
My rifle WILL NOT RUN anyother steel cased ammo - Silver Bear is it.
May 10, 2010, 03:30 PM
So, you either contaminated your chamber with zinc residue that has bonded to the chamber walls, or scratched up your chamber by using steel cases in a steel chamber, so that the steel can grip against something and fight the process of extraction.
Scrub it out WELL.
Then only shoot brass cased ammo.
I've now worked behind the line at about 20 Appleseeds. At nearly every single one of them, someone brought steel cased 5.56 or 7.62x51 ammo for an American rifle. At every single one of those rifles, they had to be taken off the line for a serious extraction related failure that rendered the rifle inoperable for the remainder of the day or weekend.
Well like I said I have shot well over 500 rounds of Silver Bear ammo with no problem at all, so something has happened to cause this problem. I am thinking its some kind of build up....
Most folks who like to defend the use of steel cased ammo like to bring up however many hundreds, or even thousands, of steel rounds they've shot in their rifle.
The simple fact is, when you rub steel against steel at high pressure and velocity, you alter the surface texture of both surfaces. When you rub an extremely soft and ductile material against a steel chamber (such as brass), the brass may shave little bits... but the steel will last a LOT longer.
You may have hosed up your chamber, and need to buy a new barrel to ultimately fix your rifle. If cleaning it WELL won't do the trick.
Friends don't let friends shoot steel cased ammo in American/NATO chambered rifles.
May 10, 2010, 08:03 PM
Well I cleaned the heck out of the chamber, BCG, and barrel there was alot of carbon build up in the BCG. I took the BCG apart and soaked it in Easy Off oven cleaner over night last night, I don't know if my gun is fixed, but it sure did remove every bit of carbon from the BCG, I also scrubed the chamber with a chamber brush to the chrome. Haven't had a chance to take it out yet will see what happens.
May 12, 2010, 05:33 PM
Well I took the gun out today didn't have any problems shooting brass or steel ammo, but I think I am going to go back to brass only. Anybody want to buy 500rds of Silver Bear real cheap.......:)
Come and take it.
May 12, 2010, 09:14 PM
foreign military brass cased surplus will have a higher probability of sticking in a chamber than steel cased.
It has nothing to do with steel case ruining the chamber. Chamber tolerances are pretty tight for most commercial ars to squeeze out accuracy. There isnt much room in there for the inevitable oil and dirt to float around. There also is less ability for cases to expand and contract.
Even lower tier AR barrels are made of some pretty hard stuff. It will take a lot more than even thousands of steel cased zinc plated or lacquer coated cases to wear the chamber out.
The barrel throat will have long ago been eroded to the point of needing to replace the barrel before the chamber will be ruined. A barrel throat that has to endure pure friction of a bullet passing through it followed by multi-thousand degree blasts of explosive gases.
A case chucking in and out of a chamber seems wimpy in comparison.
I wonder if reaming out the chamber of some AR 15s to increase the demensions slightly might fix a lot of these issues. Also bolstering extractor resistance.
May 23, 2011, 03:11 PM
SB sticking in the chamber is a known problem and happens in all levels of ARs from Colt down to Olympic. Google "Silver Bear stuck case" or "Silver Bear FTE" and follow the links.
The consensus is that the same red lacquer that is around the primer is also used when the bullet is pressed. After a few mags, the lacquer builds up and you get stuck cartridges.....especially if the round is allowed to "cook" in a hot chamber.
The only remedy seems to be to shoot slowly so your chamber stays cool (no fun with an AR) and clean the chamber every 30rds (again, no fun). You can also try wiping down all your rounds to remove any external lacquer.
If your AR doesn't run SB well, find an ammo that will. And always carry a cleaning rod to the range to push out the stuck cartridge!
Come and take it.
May 23, 2011, 03:32 PM
zinc bonds to metal alloys readily.
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