Saturday, July 2, 2016

Re-cutting a muzzle crown by hand....

The AR-15 accuracy project rifle displayed a wonky pattern on the muzzle crown after a disappointing first day at the range. Perhaps it was part of the issue with this rifle throwing patterns instead of groups, or perhaps not.  In either case, It's no longer an issue.

Using a chamfer kit purchased from Brownells a lifetime ago,  the first step after cleaning the muzzle was to square the face of the barrel at 90 degrees.

With the .22 pilot fitted to the cutting head, and a bit of lube applied, the cutter was turned by hand while applying light pressure.  Stopping to clean every few turns, it took only minutes to get what I was looking for.

The next step, after cleaning the bore once again, was to set up the 11 degree cutter and repeat the job till the rifling ended cleanly at the muzzle.

Once again, the barrel was scrubbed, and then a thread protector screwed on to.. well.... protect the threads.

The next step is a range test, to see if this work has any effect at all on the fliers and lack of accuracy.

Easy peasy, if this was all it was!


Long Island Mike said...

Quick question based on the photos. It sure looks like the crown has chattering marks on it. Was there provision for polishing the crown?

Carteach said...

Not in the kit, no. Marks like that are nearly inevitable since it's turned by hand.

I have found that a couple minutes with very fine Emery cloth covered in oil puts a nice polish on the muzzle. Just light finger pressure is all it takes

JAFO said...

Thanks for this, it looks like it will be applicable when I thread my muzzle for (gasp!) a flash suppressor. Very similar procedure, just working on the outside of the barrel.