Hello to All,

Juts had a quick peek in the Interweb :

Some tests here : http://www.accuratereloading.com/crownr.html

From http://forum.accurateshooter.com/thr...stion.3804295/ (mentioning the Precision Shooting Tests) :

March 2011 issue. .308 HB model 70...w/ fresh 11' crown 5-shot group =1.02"....w/ notch in crown @12 o'clock w/ dremel tool 5-shot group = 1.15 (mostly vertical)....dinged crown at a land with a pin punch enough to cause serious burr with metal protruding into bore, 5-shot group =.68"....half-moon cut around 1/8 of crown circumference gouging it with carbide tool, 5-shot group = .75". Finally after dinging more of the crown AND gouging the inside of the bore 1/2" deep they netted a 1.75 in group for first 5 shots....BUT the next 5-shots were .700. Go figure. ???

In the July 2000 issue they tested muzzles that were not perpendicular to the bore. One @ a 12' angle facing up and to the right, crowns finished by using JB and a brass round head screw spun in a drill. The groups from the cocked crown followed the direction of the muzzle. The factory crowned .222 TCR'83 yielded a 5-shot group of .87 moa, the cocked crown yielded a two groups that averaged .70 moa, 3-1/4" above and right of POA. Finally, the author cut the muzzle square, lapped in the crown using the JB_brass screw, and netted .72 MOA groups.
I really miss the PS rag, the issues prior to 2009.

Have fun & a good weekend

Best regards

Russ