View Single Post
Old December 9, 2018, 01:59 PM   #21
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 16,192
Case pressures that aren't too high don't stick the case to the chamber walls faster than the case backs up against the breech. When that happens, there is no case growth. The exact threshold varies with the chambering and how rough the chambers are inside. Right around 30,000 psi peak loads is the general rule of thumb with bottleneck rifle cases, but they have some forward pressure via their shoulders, so they don't back up as fast. Bottom line, it's not surprising to hear many have never seen the cases stretch. The 45 Auto rather famously gets a little shorter each load cycle. Around half a thousandth per cycle in my measurements.

As mentioned, if you have mixed brass or brass made by a manufacturer who just didn't bother to keep his manufacturing stations dialed-in to matching case cut lengths, and then combined their output later (common). Your best bet is just to sit there with a caliper and measure them all and sort them into groups by length before deciding to trim. As mentioned, this should be done after resizing.

Like the others, I assume you got a model 629 (stainless 29) or a model 69 Combat Magnum. Fingers typing faster than brain recall is all too familiar to me.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is online now  
 
Page generated in 0.09854 seconds with 8 queries