Thanks for the reply. I was about to ask about this as well. I had some the actually just stuck in the chamber, Not bolt lift, as the cam action was not discernably heavy, but the cases were sticking, again on pretty low end loads. That cleared up after a good cleaning of the chamber, but I can see how this might contribute to the chamber getting fouled easier as well.
Concave Primers, Academic Question
- Thread starter JPB4BAMA
- Start date
Dusty Stevens
Shiner
I had the same issue with Norma pre primed brass. It turned out to be the primers… I have had no issue since I have fired and reprimed my Norma rounds. Those pre primed Norma rounds will pierce also if not careful probably slightly higher (.5 gr) load as I had this happen also. I believe they are just either bad primers or really soft primers. I also started a thread on these primers on 20 practical primers caving
dcali
Bullet Maker
Just speculation, but it could be high pressure gas working back along the outside of the case and behind the primer. Then the primer hits the boltface, sealing that gas (partially at least). Then pressure drops and the high pressure behind the primer pushes it forward until the seal is broken.
I just made that all up, so take it for what it's worth.
I just made that all up, so take it for what it's worth.
Just to make sure I understand. Are you suggesting upping the FF load by half grain?, I actually went the opposite direction thinking it was the primers or higher pressure and it did not resolve the issue. Might try again at a higher load once I get a new firing pin spring.
No, when I went up a 1/2 gr I popped 2 or 3 primers. I found my load at the concave and then reloaded with cci 400’s or cci 450’s and I have been fine with both.. I tried to go up higher as I felt the primers concaved early since I had no hard bolt lift but it was a no go.. If you want to go up higher I would recommend cci450 or br4 primers but you might start working your brass a little hard. You can always go buy more brass though
So for my education, do you think springs have a "shelf life" when installed? Ask this because I traded out the whole firing pin group with one I had in storage for an upcoming build and there was no discernable difference. Waiting on my new spring now and will see how that goes, but for now changing out to another one had no effect.
Thanks
Dusty Stevens
Shiner
It may have been a bit weaker to start with. Then again you may have other issues too
My guess is that I have something else going on. Brand new firing pin assembly from PTG, and same issue, or maybe even getting worse. I'm going to go the bushing route now, as I've started piercing Remington 7-1/2 primers on the first hits of a powder ladder. Looks to be somewhere around the 45-47,000 psi Range as calculated by Quickload when tuned to observed MV from LabRadar. Using the Default Ba values i'm right at 55k. But EVERYTHING I try in consistently 100 to 200 FPS slower than the default settings predicts, and this holds pretty true through the entire charge ladder range.
Hey educate me.
I was under the belief AI brass could be formed with normal factory loads in a AI chamber and they also had the advantage of shooting well.
Then why would you download normal loads and possible invite Murphy to the party ?
Just reading this thread wants me to shovel more coal into the cases to know what a full power load would do with all other factors unchanged.
I was under the belief AI brass could be formed with normal factory loads in a AI chamber and they also had the advantage of shooting well.
Then why would you download normal loads and possible invite Murphy to the party ?
Just reading this thread wants me to shovel more coal into the cases to know what a full power load would do with all other factors unchanged.
This was a decision made from recommendations from others. The Logic goes (True or not??) that on this initial firing a lower pressure load serves to partially work harden the case head from the initial impulse without having enough pressure to cause head expansion, thus in theory making the primer pockets last longer. Does it work? I think it at least does not hurt, but since my rifle really likes the lower velocity loads best, I can't say that I am a fair test, but with that in mind, I quit counting load cycles at about 15 to 18 and the pockets are still really tight.
I also only fire form brass on fouling rounds, so for me there is no waste of components.
Well based on that why not just push them harder.
My logic tells me any load down near a starting charge has the possibility of misbehaving so if also blowing out brass to a AI chamber it seems you have left the door wide open for Murphy to come visiting.
It seems to me you made a rod for your own back.
The last comment got lost in translation between your NZ English and my South Alabama dialect.
"It seems to me you made a rod for your own back."
Would you translate please?
Made your own problem.....rod as in beat yourself up.
Take a 223 and fire it in a SAMMI chamber, result = x pressure
Take a 223 and fire it in a AI chamber, result = less than x pressure
Take a 223 case, load it light and fire it in a 223AI chamber, result is insufficient pressure to fireform the case in a AI chamber and also bring to the table other unexpected results.
Look, I'm no ballistician but the above seems just common sense to me and my advice would be to load your Norma cases with full power 223 loads and then fire them in a AI chamber where I predict you will get very different results......those results you seek.
Once formed it is just like the other Norma and Lapua. From what I see on other comments, I going with the primers are something like the rem 6-1/2 variant, just not up to snuff for a 223 load. Might be why the price was so good??? Anyway they serve the purpose as is and then look to be decent brass, but only time will tell after a few rounds around the park so to speak.
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