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Bart B. · October 9, 2012, 08:45 AM

Regarding lubing any inside part of the case, that lube needs to be removed before putting powder in the case. Otherwise, that lube will contaminate the powder it touches and change its burning characteristics. And different amounts of lube in the case mouth changes the bullet's release force needed increasing muzzle velocity and peak pressure spread. This increases vertical shot stringing on the target.

As for setting up one's die in the press, fired case shoulders need be set back enough so the bolt closes on them with zero force; no binding whatsoever. Otherwise, when the bolt binds (even the slightest amount) on the case head, it won't seat in battery exactly the same for each shot. And that degrades accuracy. If accuracy's not important, then go ahead and let the bolt bind any amount you want on your loaded rounds. Note the ejector pushes the loaded round forward perfectly centering its shoulder in the chamber shoulder where it stops even with several thousandths case head clearance to the bolt face.

Yes, set fired case shoulder back 2 to 3 thousandths; you'll get better accuracy and case life.

October 9, 2012, 08:45 AM	#11
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	Regarding lubing any inside part of the case, that lube needs to be removed before putting powder in the case. Otherwise, that lube will contaminate the powder it touches and change its burning characteristics. And different amounts of lube in the case mouth changes the bullet's release force needed increasing muzzle velocity and peak pressure spread. This increases vertical shot stringing on the target. As for setting up one's die in the press, fired case shoulders need be set back enough so the bolt closes on them with zero force; no binding whatsoever. Otherwise, when the bolt binds (even the slightest amount) on the case head, it won't seat in battery exactly the same for each shot. And that degrades accuracy. If accuracy's not important, then go ahead and let the bolt bind any amount you want on your loaded rounds. Note the ejector pushes the loaded round forward perfectly centering its shoulder in the chamber shoulder where it stops even with several thousandths case head clearance to the bolt face. Yes, set fired case shoulder back 2 to 3 thousandths; you'll get better accuracy and case life. Last edited by Bart B.; October 9, 2012 at 11:38 AM.