I notice some of my spent brass has signficant cracks at the neck and "see through" cracks at the cartridge base, above the indented primer area.  What's up? is it the gun or the ammo?  The first clip actually lost the bottom plate and seemed to have expanded at the base.  Three clips did this in sequence using this ammo.  One was a bushmaster clip and the other two were made by Center Industries in Kansas and marked "Restricted use Law Enforcement or Government use Only".  I don't think it is the gun... a Bushmaster...shorty...carbine that has seemed to do okay in the past before someone gave me their old ammo.  I think I'll toss the old stuff.  Would appreciate anyone's opinion of whether they believe it is a ammo issue or something terribly bad with the weapon.  Thanks!
Lonnie132

My first guess, ammo. The line "someone gave me their old ammo" and not mentioning a brand tips me off. Despite the stories of "I found a box of 30-06 from WWI, cracked it open, and it ran flawlessly in my Garand", ammo does not last forever, brass corrodes, and gets weaker with time.

I think you should take out some of the variables and and see if it's really your gun's fault. First, give it a really good cleaning. Follow the military cleaning manual, make sure your bolt and carrier are very clean, all that stuff. Next, buy some high quality ammo, and I don't mean moving from Wolf to Winchester White Box. Spend maybe $15 and buy two boxes of quality .223 ammunition in 55 grain. Go to the range and blast away. If your cases continue to fail, you'll know it's something to do with the gun, and you can either post your results (hopefully with pics of the cracked casings) or call up Bushmaster. Happy (trouble)shooting!

If I understand this correctly you're having case failures and mini Kbooms on every magazine ???

Get rid of that crap ammo ASAP.   You're lucky your rifle didnt come apart, it is not normal for this to happen and bulged mags are bad!     Dont fire a single round of this crap ever again or you risk life and limb.

Thank you...I'll do just that!  Lonnie132

Thank you, I'll trash the mag parts, and use some new Bushmaster mags and some high quality 223 and let you know.  It has worked fine in the past with Winchester, Hornaday and Federal manufactured ammo.  Thank you again,  Lonnie132

I had a similar thing happen with some almost 20 year old ammo. It blew the bottom of a magazine and ripped the case head off the cartridge. I tossed all the old stuff ASAP.

Quoted: I notice some of my spent brass has signficant cracks at the neck and "see through" cracks at the cartridge base, above the indented primer area.  What's up? is it the gun or the ammo?  The first clip actually lost the bottom plate and seemed to have expanded at the base.  Three clips did this in sequence using this ammo.  One was a bushmaster clip and the other two were made by Center Industries in Kansas and marked "Restricted use Law Enforcement or Government use Only".  I don't think it is the gun... a Bushmaster...shorty...carbine that has seemed to do okay in the past before someone gave me their old ammo.  I think I'll toss the old stuff.  Would appreciate anyone's opinion of whether they believe it is a ammo issue or something terribly bad with the weapon.  Thanks! Lonnie132

what is a clip?

Thanks, I'll do the same thing.  Lonnie132

Yes, toss the ammo...

Thanks, it was the old ammo.  The gun functions as it should with factory ammo. Thanks again for you advice.  Lonnie132

Another satisfied customer. Happy shooting.