http://www.canonshooter.com/photos2/M4-3.jpg
If this AR is to be used hard for possible self defense or at a training course I'd do the following:
1. Better staking of gas key (
I'd replace key with a BCM key and screws and stake with a MOACKS)
2. Install mil-spec receiver extension and stake (
Not needed your AR currently, Mil-Spec receiver extenstions are for CAR stocks, your Sully uses a 'entry length' rifle receiver extension which use a CAR buffer and spring)
3. Install heavy-duty extractor spring and insert (
I'd get the BCM SOPMOD upgrade kit which includes an extractor, pin, spring, buffer, Crane O-ring and gas rings or better yet replace the bolt with a BCM unit and use your Bushmaster bolt as a backup.)
4. I am also considering the
MGI Buffer - is it worth it? (
I'd just use an H buffer from CMT and a standard power chrome silicon spring)
5. Chip McCormick trigger group - any comments on this product (I've been shooting competitively for over 25 years and can make good use of a crisp trigger pull)? (
McCormick trigger groups are pretty good but they have a tendency to double after awhile, for a 'social' gun I'd run a stock FCG or a Geiselle)
Not related to reliability, but I am also having the AK Concepts FSC556 compensator installed in place of the lame "Izzy brake" that came from the factory (and not indexed perfectly straight as typical of BM QC). (
If the FSC556 perm. mounted will make 16" it's a good choice it's a great brake and flash hider).