Primer Blow Out with NO Over Pressure Signs?

[BuffCyclist]

Wow. All this time I have been trimming to min length or maybe a little less, sticking a bullet in 10-15 thou off the lands and calling it good.

My seat dies do not care how long my brass is. They reference the bottom of the case.

I prefer compressed charges. Lower ES and SDs normally results from it.

Are you surprised at how little of a change you get when trimming to 2.005" instead of 2.015" or surprised at the depth Belly is making me analyze the situation?

And for the record, this math is quite simple too so this level of analyzing isn't difficult. If I made a mistake, I retract my previous statement

[TheBelly]

Are you surprised at how little of a change you get when trimming to 2.005" instead of 2.015" or surprised at the depth Belly is making me analyze the situation?

And for the record, this math is quite simple too so this level of analyzing isn't difficult. If I made a mistake, I retract my previous statement

hoser cutting in kinda ruined the fun.

I was waiting to see how much further you were going to play along until you realized that those changes don't matter that much. I poked you with a stick by using math to hook you in.

Bottom line: be consistent and try to make things the same. Certain measurements matter, others don't need to be worried about as much. The measurements I worry about are:

trim to length
distance from the lands
charge weight

[Hoser]

hoser cutting in kinda ruined the fun.

Thats cause Im a dick.

[BuffCyclist]

hoser cutting in kinda ruined the fun.


I was waiting to see how much further you were going to play along until you realized that those changes don't matter that much. I poked you with a stick by using math to hook you in.


Bottom line: be consistent and try to make things the same. Certain measurements matter, others don't need to be worried about as much. The measurements I worry about are:


trim to length
distance from the lands
charge weight

No no, I ENJOY math, I was doing that on my lunch break so I win. :P


I knew those measurements would be too insignificant to matter, but the math was easy and I was bored. But that’s precisely WHY I am still befuddled, because I trimmed all brass to 2.005” with my Wilson trimmer (brand new and worked perfectly), chamfered/deburred. They all were measured exactly the same and unless the ogive moved, the rounds were all within 0.005” of each other (closer based on bullet tip measurement but as we’ve established, that isn’t a standard measurement). The charge weight is what I was trying to nail down.


Sure, I will admit now that the 42.8gr charge was probably a little too hot (why the bolt didn’t even get slightly stick on 42.4gr I don’t know) but the charges were all double checked after recalibrating the scale so why did the 38.0gr charge blow out the primer. At this point, I am still leaning towards the primers being on the smaller side of the tolerance and loose primer pockets (faulty brass), combine the two and there you have it.