Gunsmithing QD flash suppressor / muzzle break effect accuracy?

[ken226]

A few years ago I rebarreled on old Vangaurd .223 youth model for a tactical rifle build. I chambered and installed an 8.4 twist Obermeyer blank, finished at 21 inches, and opened the bolt face to .308 specs.

Im thinking I might thread the barrel on it and install a Yankee Hill QD mount.

I would be threading between centers, 5/8 x 24, using an HSS single point tool on my 12x37 lathe.

How likely is this to effect accuracy as the gun is a tack driver with 140 Amaxes?

 

[ORD]

Anytime you go messing around with your muzzle, changing the contour of the barrel which is necessary for threading, adding addt'l weight to the muzzle (be it with just a simple thread, brake/suppressor mount, and/or suppressor), or otherwise go off changing anything that can impact barrel harmonics, there is a POTENTIAL that you will impact the rifle's accuracy/performance (either positively OR negatively). Additionally, the specific design/mfg/type of brake/muzzle device itself can impact accuracy either negatively or positively, as can the manner in which the device is installed/work done to permit installation (i.e. - muzzle threaded concentrically; threads cut in/out of spec; etc.). There is no universal truth that such modifications will/won't impact your accuracy, but the potential to do so is nonetheless there.

Now, with all that said, I have had multiple plain-muzzle barrels turned down and threaded to run a muzzle device without issue over the years and I count my blessings that none have experienced any accuracy woes after the fact. YMMV!