Woo Hoo! Finally got this stupid phone to grant access to Tactical22.net. Everytime I tried accessing the site "Web Guard" blocked it. Couldn't resolve this on line so had to call CS. Dear God, what an ordeal. Unblocked now though. Damn, that phone screen is small.
On the back of the CMMG mags, near the top are two tabs that must be filed to fit your particular lower. This is to ensure a rattle free fit with any rifle. The plastic is soft and very easy to file so go a little at a time.
Hyper velocity 22lrs are usually just high velocity w/lighter bullets. Of course, the laws of physics still apply, if the bullet is traveling faster the bolt will also be traveling faster.