Carbon build up on the crown

[Spadguya1]

Pulled the brake on my Grendel earlier for cleaning and found a lot of carbon build up on the crown. Its thick and has a very uneven surface. I noticed that before the last match i was going to shoot, it no longer grouped at all at 100yds. Over the last two to three hundred rounds ive noticed it open up and no longer an MOA rifle. Can this build up affect grouping for zero check? Thanks for any info. [ATTACH=CONFIG]14707[/ATTACH]

[FRB6.5]

More likely it is the brake itself:
http://bulletin.accurateshooter.com/2019...-cleaning/

[Lemonaid]

Builds up on the crown using flash hiders as well. I like just a thread protector now.

[A5BLASTER]

Looks like your brake isn't sitting square to the crown face.

When I pull my brake or flash hider off its a nice even star pattern in the carbon build up.

I haven't noticed any degration of accuracy in my rifles due to it but I will keep a log on it now to see if I can find a pattern to it.

I typically clean the crown bout every 500 rounds when I do my 500 round tear down for cleaning and maintenance.

[centerfire]

Looks normal, leave it alone and shoot it.

[Spadguya1]

Thanks foe the heads up to all. Ive loaded up more rnds with fresh XBR and gonna give it a work out saturday. Ill post the results then.

[snarkscarbine]

I wouldn?t worry about it. All my rifles have that, and my most accurate rifles shoot 1/3moa whether clean or caked up. I stopped paying any attention to carbon cake after a while because it didn?t seem to make any difference.