AR-Whisper feeding problems

[sgms18]

I am shooting 220gr Sierra pro hunters. when I load less than 10 rounds in a mag they work like a champ, more than 10 rounds the soft round nose cathhes the very front top of the mag when the bolt trys to strip off a round, every time. Anyone else had feeding issues like this? What mags are yall using? I am using Colt 20 rounders. Any Sugestions??

[nwcid]

I tried the Colts and I shoot 220gr Hornady RN bullets. They would not feed for me, IIRC the bullet would start out but the case would hang up on the mag lip.

I got a 20rd Pmag locally to try and it works great. Since I am running OD color mags as soon as they came out I ordered a dozen of them and have run about half and no problems.

[Alleycat]

I use a Dremel. Round off all the edges especially the front of the mag. You usually catch the mouth of the case on the sharp edge of the mag and then all kinds of bad things happen.