King Arms M4 Midcap magazine jamms

theburi

HI
Did anyone expirience with jamming mid-cap magazines?
I've got 5 King Arms m4 120 rounds magazines and all of them jam bb's.

Silicon oil didn't do the trick.

And yes, one of the magazines split in half under loading pressure when half filled.

Any sugestions?

Cheeky monkey

Is the spring like just stopping on its way up?

theburi

I think it's two bb's get jammed in a channel agains each other.
After a strong bang they usually unlock.

Cheeky monkey

I was thinking it could just be a bend in the spring but I'm not sure tbh

Masada

ya must of have a conciderable amount of force on it to split a mag but it could be something as simple as left over mounding flash inside the mags thats interfereing with the path of the spring. open one up and make sure theres nothing in the springs path that might catch it on the way up., if there is you can smooth it with a dremel or a piece of sandpaper.,

theburi

Ok, I give up. Polishing inside is no good.
Silicon doesn't do the trick
Does anybody have KingArms M4 120 rounds mags working?

Puding

How many bbs are you filling the mag with each time? i had a some of the king arms m16/m4 mags with the hk markings and to get them to reliable feed i had to only load them with about 100bbs if i tried to go load them with the max i would constantly get jams as the bbs would not feed properly.

theburi

I've tried different combinations from 4-120 rounds.
Magazine get jammed every4-5 round. It will let 4 rounds through and will get jammed. After a kick it will let out another 4-6 rounds.
All my 5 mags are the same.

The only explanaition is that I use Silicon oil may be too much. I'll try to see if drying it will solve the problem.

Cheeky monkey

Grab yourself some tissue and get rid of the silicon and then get some sand paper and sand down the inside a little just to make sure theres no in perfections that are causing it to jam

Puding

this is more a problem with ka m14 mid caps but it does come up know and then with other mags they produce the parted labeled bellow can sometimes be a bit too long and cause jams, normal only about 1mm need to be sanded away.