The Firing Line Forums - View Single Post - Where the heck are all the muzzle crowning tools??

BobGee · September 18, 2012, 09:51 AM

Hi Unclenick, Thanks for the advice in your attachment (Crown Ball Lapping2.PDF). I shall be re-crowning my Walther GPS-C barrel using it this weekend.

However, although this post is old, for the sake of posterity I think I should mention that the formula for choosing the lapping ball size is incorrect. The diameter (phi) should be: D/sin"theta", not 2D/sin"theta".

Thanks again for the info.

September 18, 2012, 09:51 AM	#13
BobGee Junior Member Join Date: September 18, 2012 Location: Sydney, Australia Posts: 1	Ball size Hi Unclenick, Thanks for the advice in your attachment (Crown Ball Lapping2.PDF). I shall be re-crowning my Walther GPS-C barrel using it this weekend. However, although this post is old, for the sake of posterity I think I should mention that the formula for choosing the lapping ball size is incorrect. The diameter (phi) should be: D/sin"theta", not 2D/sin"theta". Thanks again for the info.