I just purchased a new Bushmaster M-4 i took it to the range to day for the first time and i kept getting a double feed malfunction. A few years ago I got a 20 in. bushmaster that had the same problem but it has since seemed to work its self out is this normal? or is there something wrong.

Troubleshooting Forum

Did you clean and lube the weapon before the range trip?

What type of mags were you using?

What type of ammo, and have you used it successfully in other ARs?

live round empty case.

Quoted: Did you clean and lube the weapon before the range trip? What type of mags were you using? What type of ammo, and have you used it successfully in other ARs?

cleaned thourouly and lubed well. im using new gi mag's. and im using winchester 55gr fmj. ive used this ammo in other ar's with no problem. this is the 4th ar that ive broken in between mine and some friends and have the same problem

With what ammo?
New carbine did the same with wolf  for the first 500 rds.  hotter stuff worked no problems

Quoted: With what ammo? New carbine did the same with wolf  for the first 500 rds.  hotter stuff worked no problems

winchester 55gr fmj

Quoted: I just purchased a new Bushmaster M-4 i took it to the range to day for the first time and i kept getting a double feed malfunction. A few years ago I got a 20 in. bushmaster that had the same problem but it has since seemed to work its self out is this normal? or is there something wrong.

And here I am sitting here giggling as I'm left wondering if you used the same mag in both bushys. LOL!!!....point being...from my experience with a number of box fed auto's most true "Double Feed" malfunctions are caused by "mag issues" rather than "reciever/bolt issues" as follows...the three most common mag related causes are...

1. The catch tang/tit on the mag (the protrusion that engages the mag release mechanism) that keeps it locked in place is mis-adjusted/set on the high side...then as the shot is fired the bolt/bolt carrier assy. conflicts with and kicks the top round out of the mag lips...on it's rearward travel...then after it's ejected the spent brass and starts it's way forward?..it picks up another round (as it's supposed to) on it way back home...except now there's two live rounds...which is a real bad situation as the point of the rear round can slam fire the first one that popped out...not good...stop firing until it's addressed....to wit?...a process called "Setting The Mag"...which involves seperating the upper so you cane insert the mag and SEE how high the first round is setting...and if it's too high?...file away a little of the mag catch protrusions bottom surface to let it sit lower....or?...if you have several mags and they are ALL seated to high then chances are you need to whiddle some off your mag catch surface...cause this would indicate your mag catch surface is too high and not the mags.

and....

2. (which can also co-exist and amplify condition #1 above)...is where you mag lips have opened up to wide...either deformed or worn out....and they're barely keeping the rounds in the mag when loaded....especially with a topped off/full mag....again...stop firing and address this situation asap....either bend the mag retention lips inward slightly or...buy a new mag if the lips are worn away.

3. "A Hanging/Sticky Mag Follower"....which can get stuck at a certain point rendering all preceding rounds loose in the mag with zero spring tension and could theoretically "BOUNCE" under recoil...but it's rare and I don't think that's your situation here...but check that your mag follower is operating smoothly anyways.

That's all I can think of and hope it may help. L8R, Bill.

Quoted: Quoted: I just purchased a new Bushmaster M-4 i took it to the range to day for the first time and i kept getting a double feed malfunction. A few years ago I got a 20 in. bushmaster that had the same problem but it has since seemed to work its self out is this normal? or is there something wrong. And here I am sitting here giggling as I'm left wondering if you used the same mag in both bushys. LOL!!!....point being...from my experience with a number of box fed auto's most true "Double Feed" malfunctions are caused by "mag issues" rather than "reciever/bolt issues" as follows...the three most common mag related causes are... 1. The catch tang/tit on the mag (the protrusion that engages the mag release mechanism) that keeps it locked in place is mis-adjusted/set on the high side...then as the shot is fired the bolt/bolt carrier assy. conflicts with and kicks the top round out of the mag lips...on it's rearward travel...then after it's ejected the spent brass and starts it's way forward?..it picks up another round (as it's supposed to) on it way back home...except now there's two live rounds...which is a real bad situation as the point of the rear round can slam fire the first one that popped out...not good...stop firing until it's addressed....to wit?...a process called "Setting The Mag"...which involves seperating the upper so you cane insert the mag and SEE how high the first round is setting...and if it's too high?...file away a little of the mag catch protrusions bottom surface to let it sit lower....or?...if you have several mags and they are ALL seated to high then chances are you need to whiddle some off your mag catch surface...cause this would indicate your mag catch surface is too high and not the mags. and.... 2. (which can also co-exist and amplify condition #1 above)...is where you mag lips have opened up to wide...either deformed or worn out....and they're barely keeping the rounds in the mag when loaded....especially with a topped off/full mag....again...stop firing and address this situation asap....either bend the mag retention lips inward slightly or...buy a new mag if the lips are worn away. 3. "A Hanging/Sticky Mag Follower"....which can get stuck at a certain point rendering all preceding rounds loose in the mag with zero spring tension and could theoretically "BOUNCE" under recoil...but it's rare and I don't think that's your situation here...but check that your mag follower is operating smoothly anyways. That's all I can think of and hope it may help. L8R, Bill.hr

Thank's for your help.

thanks for your help