Originally Posted by robocop10mm
I agree with Tango, STOP! If the results you are getting are that erratic, there is something VERY wrong. Continuing to "experiment" with an explosive device inches from your face will very likely result in the removal of said face.
What powder are you using? What primers? Very light loads can give higher pressures than compressed loads with some powders. How long have you been reloading? There are some complexities that can get you seriously hurt.
I did stop thats why I'm here. As for reloading I've been doing it for ten years. I know not very long compared to some of you (that's also why I'm here)
The problem is not the powder (868 mil surplus) the primer (WLRM) or the bullet 140 gn sierra spitzer (I know cheapies, but I didnt want to waste all the good ones) or the book Lyman #6.
I've been reloading this rifle for a while now without problems. The only time it's presented issues it with "new" or "factory" brass. My 2-3-4th fired brass holds up just fine up to 72 gns of the 868. At that point it shows pressure with squared corner on the primer and a slight "pit" where the pin hit (raised edge)
I can NOT run the same load in a fresh case! when I did it blew the primer right out and ruined the case, not to mention my nerves. Thinking It had to be operator error I loaded 2 more identical rounds (double checked my loads with 2 scales digital and old school rcbs) old and new cases with exactly the same results. Thats when I loaded down the charge to the minimums. When those didn't work either (in the new cases) I examined EVERYTHING in the rifle including mag'ing the bolt for cracks (to restore my faith in it)
So since then:
cleaned chamber with saami spec reamer from PTG
throated barrel to saami spec
purchased belted mag go/no-go gages
re-headspaced reciever to barrel (was out .007 over no-go)
mag inspected bolt for cracks
checked barrel twist
checked barrel for straightness
fire formed 1 new case with 25 gns 868
re fired case with 55 gns (ok)
re fired case with 60 gns (ok)
re fired case with 65, and then 70 (ok)
The same case works flawlessly with IMR 4064 and 4350 (48 and 53 gns respectivly) The same charges in new cases destroys them! The rifle is secured in a shooting bench, sand bagged in, and remotely fired
I do understand your need for concern and safety because you never know who you end up talking to on a forum and I do heed your warnings I'd also NEVER do this to someone elses weapon LOL. but since it's mine and only $75...... ummm $250 by now I felt free to figure it out. I've gone through curiosity to puzzlement to frustration to anger back to curiosity now.
Checked every aspect of the new vs old case
weight, volume, neck thickness etc.... only slight variations. the volume was off by 1 gn, neck thickness .002
So while I can make a "safe" load using fire formed brass I'm not happy with that result. I want to know why the new brass will not function properly. It's a HUGE safety issue with me! I know I'm missing something I just don't know what.