Bushmaster carbon 15 problems

[klutchless]

I have a carbon 15 that wont load remington jacketed hollowpoints it loads steelcase wolf fmj and winchester cxp1 just fine but with the remington it fires the first round and jams the second in the mag. I tried magpul 5 and 30 rounders along with a pmag 30 and two bushmaster 30 i think the recoil is maybe disengaging the mag when i shoot the mag comes loose but is still locked in the lower im lost on this gun. I wouldnt make a big fuss over it normaly i know some ar's are fussy about ammo but I ordered 500 rounds and have nothin to shoot them out of unless I go single shot .Any help advise or even opinions and guesses are appreciated.:banghead:

 

[rcmodel]

It woulld help if you could describe exactly how the jam occurs?

Is the bolt running over the round in the mag?
Or failing to even pick it up and start it towards the chamber?
Or is the bullet jammed down into the front of the mag?
Or is the bUllet jammed up into the barrel extension?
Or is the cartridge case dented or bent in the middle?

Without knowing exactly what type of jam you are getting I can't be of much help.

rc

 

[klutchless]

Sorry about not being clear it jammes front of bullet into mag thats why i thought it was the mag spring an bought a bunch of new mags and still no luck. Unless i have six new mags with messed up springs the bolt is half engaged on the rear of the bullet like its supposed to to push it into battery but the shell wont move my uncle said it was the way i load my mags and it causes the second round to be to far forward and nose dive into the mag but i dont this is the issue because i load my other rounds the same way and no malfunction.Are remington rounds shorter than cxp1 they dont look to be but i dont have a caliper to go into .00 millameters.

 

[rcmodel]

O.K.
You said it works fine with Wolf steel case & Win CXP1, but doesn't work with Remington?

I know the Wolf steel has polymer coated cases, and I believe the CXP1 has nickle plated cases. Both are very slick.

The Remington has plain brass cases.

That leads me to believe it is friction on the mag feed lips causing excess drag on the Rem ammo, which in turn is causing it to nose dive into the mag.

1. It may be due to all your new magazines having rough finish build-up under the feed lips.
2. It may be due to the mag springs not providing enough upward pressure on the front of the followers.

Both can be addressed by taking the floor-plate off the mag and removing the spring and follower.

1. Use some 400 grit emery paper to polish the bottom edges of the feed lips where the rounds rub on them.
2. Bend the front of the mag spring UP a little to put more pressure under the front of the follower.
See this about that:
http://www.zediker.com/articles/AR_magazines.pdf

The other thing to do is, once you fully load a mag, whack the back edge against your boot heel or a wood bench leg to seat all the rounds against the back of the mag.

That insures they are all properly aligned and against the back of the mag and can get a good running start out of the mag when the bolt shoves them out.

You also said:

i think the recoil is maybe disengaging the mag when i shoot the mag comes loose but is still locked in the lower

Try holding the mag fully up in the gun with your support hand while shooting and see if that makes any difference.

If it does, you may have a defective or improperly installed mag catch.
Or an out of spec lower receiver with a loose or out of position mag catch hole.
Carbon-15's are known to be problematic at times due to the plastic molding not being as good as it should have been.
My hunting buddies son had one we never could get to work like an AR-15 should.
He finally sold it and cut his losses.

However, with that said, I doubt the mag being loose and dropping down too far is causing the nose-down jams. If it were causing a problem by dropping too low in the lower, it would likely manifest itself with the bolt over-running the rounds all together and failing to even pick them up.

If all the above fails to solve your feed problem, I would suggest you give Bushmaster customer service a call and see if they can fix it under warranty.
The phone number is: 1-800-998-7928

BTW: A properly built AR-15 is not ammo sensitive in the slightest.
I have an early 1970's Colt Carbine that has never failed to feed anything I put in it & about 20 different magazines in the last 40 years!

rc

 

[halogrinder]

how "wet" is it?


AR15's like to run WET.


i take the bolt, and literally dunk it in motor oil for 2-3 seconds, then give it one SHAKE and stick it in.

whatever it doesnt want, it spits/burns out. i have GREAT success with that.

i also oil the hell out of the buffer tube and spring.

 

[klutchless]

Thanks for the advice tore down the bushmaster 30 rounder and polished it op with some 800 grit wet sand paper and finished it with a touch of miguires wax going in the same direction back to front functions perfect should I repaint the bare metal at the front of the follower or just keep it waxed and forget it. As for the mag you were correct and the release was installed off kilter because the hole in the lower was full of plastic burrs took it out with the help of bushmaster customer service on the phone as i did it sanded off the burrs went right in and works great. p.s id love to have a steel ar but cant afford one yet they seem to eat up whatever load is hot enough function the gun. I seriously debated building one but with all the ffl fees its cheaper just to buy a smith in Ohio anyways and i didnt want a 400 dollar you assemble gunshow box of parts.again thanks for all your help.